ICs for Communications
ISDN Subscriber Access Controller for Terminals
ISAC®-S TE
PSB 2186
User’s Manual 10.94
Data Classification
Maximum Ratings
Maximum ratings are absolute ratings; exceeding only one of these values may cause
irreversible damage to the i ntegrat ed circu i t.
Characteristics
The listed characteristics are ensured over the operating range of the integrated circuit. Typical
characteristics specify mean values expected over the production spread. If not otherwise
specified, typical characteristics apply at TA = 25 °C and the given supply voltage.
Operating Range
In the operating range the functi ons given in the circuit description are fulfilled.
For detailed technical information about “Processing Guidelines” and “Quali ty Assurance ”
for ICs, see our “Product Overview”.
PEB 2186
Revision History: 10.94
Previous Re leases: 11.88; 3.89; 12.89; 02.95
Page Subjects (changes since last revision)
The present doc umentation is an editorial updat e of the
Technical Manu al 12.89
Edition 10.94
This edition was realized using the software system FrameMaker
Published by Siemens AG, Breech Belittler, Marketing-Communication,
Banisters 73, D-81541 Munching.
Siemens AG 1994. All Rights Reserved.
As far as patents or other rights of third parties are concerned, liability is only assumed for components per se, not
for applications, processes and circuits implemented within components or assemblies.
The information describes the type of component and shall not be considered as assured characteristics.
Terms of delivery and rights to change design reserved.
For questions on technology, delivery, and prices please contact the Offices of Semiconductor Group in Germany
or the Siemens Companies and Representatives worldwide (see address list).
Due to technical requirements components may contain dangerous substances. For information on the type in
question please contact your nearest Siemens Office, Semiconductor Group.
Siemens AG is an approved CECC manufacturer.
General Infor mati on
Table of Contents Page
Semiconductor Group 3
1Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.1 Pin Definitions and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.2 Logic Symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.3 Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.4 System Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
1.4.1 ISDN Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
1.4.2 Microprocessor Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2 Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.1 General Functions and Device Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2 Interface and Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.3 IOM®-2 Mode Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.3.1 Basic IOM®-2 Frame Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.3.2 IOM®-2 Interface Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.3.3 mP Access to B and IC Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.3.4 MONITOR Channel Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.3.5 C/I-Channel Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.3.6 TIC-Bus Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.4 Layer-1 Functions for the S/T Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.4.1 S/T Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.4.2 Analog Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.4.3 S/T-Interface Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
2.4.4 S/T Interface Pre-Filter Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
2.4.5 Receiver Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
2.4.5.1 Receive Signal Oversampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
2.4.5.2 Adaptive Receiver Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
2.4.5.3 Level Detection Power Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
2.4.6 Timing Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
2.4.7 Activation/Deactivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
2.4.7.1 FAinfA_1fr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
2.4.7.2 FAinfB_1fr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
2.4.7.3 FAinfD_1fr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
2.4.7.4 FAinfA_kfr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
2.4.7.5 FAinfB_kfr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
General Infor mati on
Table of Contents Page
Semiconductor Group 4
2.4.7.6 FAinfD_kfr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
2.4.7.7 FAregain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
2.4.8 D-Channel Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
2.4.9 S- and Q-Channel Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
2.5 Terminal Specific Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
2.6 Test Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
2.7 Layer-2 Functions for the ISDN-Basic Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
2.7.1 Message Transfer Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
2.7.2 Protocol Operations (auto-mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
2.7.3 Reception of Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
2.7.4 Transmission of Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
2.7.5 Documentation of the Auto Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
2.7.5.1 Legend of the Auto-Mode Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
2.7.5.2 Additional General Considerations when Using the Auto Mode . . . . . . . . . . . . . . 77
2.7.5.3 Dealing With Error Conditions in Auto Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
3 Operational Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
3.1 Microprocessor Interface Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
3.2 Interrupt Structure and Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
3.3 Control of Layer 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
3.3.1 Activation/Deactivation of IOM® Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
3.3.2 Activation/Deactivation of S/T Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
3.3.2.1 Layer-1 Command/Indication Codes and State Diagrams . . . . . . . . . . . . . . . . . . 125
3.3.3 Example of Activation/Deactivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
3.4 Control of Layer-2 Data Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
3.4.1 HDLC-Frame Reception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
3.4.2 HDLC-Frame Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
3.5 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
3.6 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
4 Detailed Regi ster Descriptio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
4.1 HDLC Operation and Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
4.1.1 Receive FIFO RFIFO Read Address 00-1FH . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
4.1.2 Transmit FIFO XFIFO Write Address 00-1FH . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
4.1.3 Interrupt Status Register ISTA Read Address 20H . . . . . . . . . . . . . . . . . . . . . . . 146
General Infor mati on
Table of Contents Page
Semiconductor Group 5
4.1.4 Mask Register MASK Write Address 20H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
4.1.5 Status Register STAR Read Address 21H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
4.1.6 Command Register CMDR Write Address 21H . . . . . . . . . . . . . . . . . . . . . . . . . . 149
4.1.7 Mode Register MODE Read/Write Address 22H . . . . . . . . . . . . . . . . . . . . . . . . . 150
4.1.8 Timer Register TIMR Read/Write Address 23H . . . . . . . . . . . . . . . . . . . . . . . . . . 152
4.1.9 Extended Interrupt Register EXIR Read Address 24H . . . . . . . . . . . . . . . . . . . . 154
4.1.10 Transmit Address 1 XAD1 Write Address 24H . . . . . . . . . . . . . . . . . . . . . . . . . . 155
4.1.11 Receive Frame Byte Count Low RBCL Read Address 25H . . . . . . . . . . . . . . . . 156
4.1.12 Transmit Address 2 XAD2 Write Address 25H . . . . . . . . . . . . . . . . . . . . . . . . . . 156
4.1.13 Received SAPI Register SAPR Read Address 26H . . . . . . . . . . . . . . . . . . . . . . 156
4.1.14 SAPI1 Register SAP1 Write Address 26H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
4.1.15 Receive Status Register RSTA Read Address 27H . . . . . . . . . . . . . . . . . . . . . . 157
4.1.16 SAPI2 Register SAP2 Write Address 27H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
4.1.17 TEI1 Register 1 TEI1 Write Address 28H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
4.1.18 Receive HDLC Control Register RHCR Read Address 29H . . . . . . . . . . . . . . . . 160
4.1.19 TEI2 Register TEI2 Write Address 29H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
4.1.20 Receive Frame Byte Count High RBCH Read Address 2AH . . . . . . . . . . . . . . . 161
4.1.21 Status Register 2 STAR2 Read/Write Address 2BH . . . . . . . . . . . . . . . . . . . . . . 162
4.2 Special Purpose Registers: IOM®-2 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
4.2.1 Serial Port Control Register SPCR Read/Write Address 30H . . . . . . . . . . . . . . . 163
4.2.2 Command/Indication Receive 0 CIR0 Read Address 31H . . . . . . . . . . . . . . . . . 164
4.2.3 Command/Indication Transmit 0 CIX0 Write Address 31H . . . . . . . . . . . . . . . . . 165
4.2.4 MONITOR Receive Channel 0 MOR0 Read Address 32H . . . . . . . . . . . . . . . . . 166
4.2.5 MONITOR Transmit Channel 0 MOX0 Write Address 32H . . . . . . . . . . . . . . . . . 166
4.2.6 Command/Indication Receive 1 CIR1 Read Address 33H . . . . . . . . . . . . . . . . . 166
4.2.7 Command/Indication Transmit 1 CIX1 Write Address 33H . . . . . . . . . . . . . . . . . 166
4.2.8 MONITOR Receive Channel 1 MOR1 Read Address 34H . . . . . . . . . . . . . . . . . 167
4.2.9 MONITOR Transmit Channel 1 MOX1 Write Address 34H . . . . . . . . . . . . . . . . . 167
4.2.10 Channel Register 1 C1R Read/Write Address 35H . . . . . . . . . . . . . . . . . . . . . . . 167
4.2.11 Channel Register 2 C2R Read/Write Address 36H . . . . . . . . . . . . . . . . . . . . . . . 167
4.2.12 B1-Channel Register B1CR Read Address 37H . . . . . . . . . . . . . . . . . . . . . . . . . 168
4.2.13 Synchronous Transfer Control Register STCR Write Address 37H . . . . . . . . . . . 168
4.2.14 B2-Channel Register B2CR Read Address 38H . . . . . . . . . . . . . . . . . . . . . . . . . 169
General Infor mati on
Table of Contents Page
Semiconductor Group 6
4.2.15 Additional Feature Register 1 ADF1 Write Address 38H . . . . . . . . . . . . . . . . . . . 170
4.2.16 Additional Feature Register 2 ADF2 Read/Write Address 39H . . . . . . . . . . . . . . 171
4.2.17 MONITOR Status Register MOSR Read Address 3AH . . . . . . . . . . . . . . . . . . . . 172
4.2.18 MONITOR Control Register MOCR Write Address 3AH . . . . . . . . . . . . . . . . . . . 172
4.2.19 S-, Q-Channel Receive Register SQRR Read Address 3BH . . . . . . . . . . . . . . . 173
4.2.20 S, Q Channel Transmit Register SQXR Write Address 3BH . . . . . . . . . . . . . . . . 174
5 Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
6ISAC®-S TE Low Level Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
6.1 Architecture and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
6.2 Summary of LLC Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
6.2.1 Layer-1 Related Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
6.2.2 HDLC-Controller Related Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
6.2.3 External Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
6.3 LLC-Code Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
6.3.1 Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
6.3.2 Definitions and Naming Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
6.3.2.1 Type Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
6.3.2.2 Macro Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
6.4 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
6.5 LLC-Routine Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
6.5.1 ISAC®-S TE Layer-1 Functions: The SBC Part . . . . . . . . . . . . . . . . . . . . . . . . . . 201
6.5.2 ISAC®-S TE HDLC-Controller Related Functions: The ICC Part . . . . . . . . . . . . 202
6.6 Listing of Driver Routines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
7 Package Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
IOM®, IOM®-1, IOM®-2, SICOFI®, SICOFI®-2, SICOFI®-4, SICOFI®-4µC, SLICOFI®, ARCOFI® , ARCOFI®-BA, ARCOFI®-SP,
EPIC®-1, EPIC®-S, ELIC®, IPAT®-2, ITAC®, ISAC®-S, ISAC®-S TE, ISAC®-P, ISAC®-P TE, IDEC®, SICAT®, OCTAT®-P,
QUAT®-S are registered trademarks of Siemens AG.
MUSAC™-A, FALC™54, IWE™, SARE™, UTPT™, ASM™, ASP™ are trademarks of Siemens AG.
Purchase of Siemens I2C components conveys a license under the Philips’ I2C patent to use the components in the I2C-system
provided the system conforms to the I2C specifications defined by Philips. Copyright Philips 1983.
Semicond uctor Group 7
General Information
Introduction
The PSB 2186 ISAC®-S TE implements the four-wire S/T interface used to link voice/data
terminals to an ISDN.
The PSB 2186 combines the functions of the S-Bus Interface Circuit (SBC: PEB 2080) and the
ISDN Communications Controller (ICC: PEB 2070) on one chip.
The compo nent switch es B- and D-cha nnels be tween the S/ T and the ISDN Ori ented Mo dular
(IOM®) interfaces, the latter being a standard backplane interface for the ISDN-basic access.
The device pro vides all electr ical and logica l functions of the S/T interf ace, such as: activat ion/
deactivation, mode dependent timing recovery and D-channel access and priority control.
The HDLC pa ckets of the IS DN D-channe l are ha ndled by t he ISAC -S which int erface s them
to the associated microcontroller. In one of its operating modes the device offers high level
support of layer-2 functions of the LAPD protocol.
The ISAC-S is a CMOS device, available in a P-DIP-40, P-LCC-44, P-MQFP-64 package. It
operates from a single + 5 V supply and features a power-down state with very low power
consumption.
Semicond uctor Group 8
10.94
ISDN Subscriber Access Controller PSB 2186
for Terminals (ISAC®-S TE )
Preliminary Data CMOS IC
P-MQFP-64
P-LCC-44
P-DIP-40
1Features
Terminal IOM®-2 terminal specific version of the
PEB 2086:
●Pin and software compatible to P EB 2086
●Compatible to PEB 2085 (Symmetrical Receiver)
●Full duplex 2B+ D S/T interface transcei ver accordi ng to
CCITT I.430
●Conversion of the frame structure between the
S/T interface and IOM-2
●Receive timing recovery
●D-channel access control
●Activation and deactiv ation procedures with automatic
wake-up from power-d own st ate
●Access to S and Q bits of S/T interface
●Adaptively switched receive thresholds
●Support of LAPD protocol
●FIFO buffer (2 x 64 bytes) for efficient transfer of
D-channel pac kets
●8-bit microprocessor interface, multiplexed or
non-multiplexed
●Serial interface: IOM-2 interface including bit clock and
strobe signal
●Implementation of IOM-2 MONITOR and C/I-channel
protoc ol to co ntrol peripheral devices
●Microprocessor access to B- and intercommunication-
channels
●Watc hd og ti me r
●Advanced CMOS technology
●Low power consumption: standby: 8 mW; active: 80 mW
The PSB 2186, ISAC-S TE is software compatible to the PEB 2085, ISAC-S.
Type Ordering Code Package
PSB 2186H Q67100-H6412 P- MQFP- 64 (SMD)
PSB 2186N Q67100-H6390 P-LCC-44 (SMD)
PSB 2186P Q67100-H6389 P-DIP-40
Semiconductor Group 9
Features
Pin Configuration
(top view)
ITP04470
PSB 2186
16 33
N.C.
63
V
DD
V
SSA
A3
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
N.C.
17
N.C.
18
N.C.
19
20
SX1
21
SX2
22
IDP0
23
IDP1
24
ALE
25
CS
26
WR(R/W)
27
RD(DS)
28
A0
29
N.C.
30
N.C.
31
SR1 N.C.
N.C.
34
N.C.
SR2
35
N.C.
36
N.C.
XTAL1
37
AD0
XTAL2
38
AD1
39
AD2
N.C.
40
AD3
INT
41
AD4
BCL
42
AD5
43
AD6
N.C.
44
AD7
N.C.
45
N.C.
N.C.
46
N.C.
N.C.
47
N.C.
N.C.
48
N.C.
62
A4
61
N.C.
60
59
N.C.
58
FSC1
57
DCL
56
55
EAW
54
A5
53
RST
52
N.C.
51
SDS1
50
A1
49
A2
N.C.
32
64
DD
V
V
SSD
SSD
V
/D7
/D6
/D5
/D4
/D3
/D2
/D1
/D0
(DU)
(DD)
SSD
V
P-LCC-44
P-MQFP-64
ITP04471
PSB 2186
AD2
A0
AD0
AD1
AD3
AD4
AD5
AD6
AD7
A2
SDS1
N.C.
RST
EAW/A5
DCL
FSC1
N.C.
N.C.
A4
6 5 4 3 2 1 44 43 42 41 40
17
16
15
14
13
12
11
10
9
8
739
38
CS
37
ALE
36
IDP1
35
IDP0
34
SX2
33
SX1
32
31
N.C.
30
N.C.
29
SR1
SR2
XTAL1
XTAL2
INT
BCL
N.C.
A3
2827262524232221201918
V
SSA
V
SSD
V
DD
A1
N.C.
SSD
V
SSD
V
/D0
D1/D2/D3/D4/D5/D6/D7/
RD(DS)
WR(R/W)
(DU)
(DD)
Semicond uctor Group 10
Features
Pin Configuration
(top view)
ITP04469
PSB 2186
INT 20
BCL 19
18
N.C. 17
N.C. 16
N.C. 15
14
N.C. 13
FSC1 12
DCL 11
10
EAW 9
RST 8
N.C. 7
SDS1 6
N.C. 5
AD7 4
AD6 3
AD5 2
AD4 1
XTAL2
XTAL1
SR2
SR1
N.C.
N.C.
SX1
SX2
IDP0
IDP1
ALE
CS
WR
RD
AD0
AD1
AD2
AD340
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
V
SSD
V
SSA
V
DD
SSD
V
SSD
V
(DU)
(DD)
P-DIP-40
Semicond uctor Group 11
Features
1.1 Pin Definitions and Functions
Pin No.
P-DIP-40 Pin No.
P-MQFP-64 Pin No.
P-LCC-44 Symbol Input (I)
Output (O)
Open
Drain (OD)
Function
37
38
39
40
1
2
3
4
37
38
39
40
41
42
43
44
41
42
43
44
1
2
3
4
AD0/D0
AD1/D1
AD2/D2
AD3/D3
AD4/D4
AD5/D5
AD6/D6
AD7/D7
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
Multiplexed Bus Mode:
Address/data bus transfers
addresses from the µP system
to the ISAC-S TE and data
between the µP system and
the ISAC-S TE.
Non-Multiplexed Bus Mode:
Data bus. Transfers data
between the µP system and
the ISAC-S TE.
34 27 37 CS I Chip Select: A “Low“ on this
line selects the ISAC-S TE for
a read/write operation.
–
35
28
28
38
38
R/W
WR
I
I
Read/Write: When “High”
identi fies a valid µP access as
a read operation. When “Low”,
identi fies a valid µP access as
a write oper ation (Motorola
bus mode ).
Write: This signal indicates a
write operation (Intel bus
mode).
–
36
29
29
39
39
DS
RD
I
I
Data Strobe: The rising edge
marks the end of a valid read
or write operation (Motorola
bus mode ).
Read: This signal indicates a
read operation (Intel bus
mode).
20 8 23 INT OD Interrupt Request: The signal
is activated when the ISAC-S
TE requests an interrupt. It is
an open drai n out put.
Semicond uctor Group 12
Features
33 26 36 ALE I Address Latch Enable: A
high on this line indicates an
address on the address/data
bus (mul tiplexed bu s type
only). ALE also selects the
microprocessor interface type
(multiplexed or non-
multiple xed) P-LCC and
P-MQFP only.
8 54 9RSTI/OReset: A “High“ on this input
forces the ISAC-S TE into
reset state. The minimum
pulse length is four DCL-clock
periods or four ms. If the
terminal specific functions are
enabled, the ISAC-S TE may
also supply a reset signal.
12 59 13 FSC1 O (I) Frame Sync 1:
Fram e sync output. “Hig h“
during channel 0 on t he IOM-2
interface. FSC1 becomes
Input if Test Mode is
programmed (ADF1).
11 58 12 DCL O (I) Data Clock: Clock of
frequency equal to twice the
data rate on the IOM-interface
Clock output 1536-kHz
IOM-2 mode
DCL becomes Input if Test
Mode is programmed (ADF1).
–
–
–
–
–
–
30
51
50
64
63
55
40
6
5
18
17
10
A0
A1
A2
A3
A4
A5
I
I
I
I
I
I
Address Bit 0
Address Bit 1
Address Bit 2(Non-multiplexed
Address Bit 3bus mo de)
Address Bit 4
Address Bit 5
1.1 Pin Definitions and Functions (cont'd)
Pin No.
P-DIP-40 Pin No.
P-MQFP-64 Pin No.
P-LCC-44 Symbol Input (I)
Output (O)
Open
Drain (OD)
Function
Semicond uctor Group 13
Features
9 56 10 EAW I External Awake (terminal
specific function). If a falling
edge on t hi s i np ut is det ecte d,
the ISAC-S TE generates an
interrupt and, if enabled, a
reset pulse.
6 52 7SDS1OSerial Data Strobe 1.
A programmable strobe signal,
selecting either one or two B-
or IC-channels on IOM-2
interface, is supp lied via this
line. After reset, SDS1 takes
on its function only after a write
access to SPCR is made.
19 7 22 BCL O Bit Clock: Clock of frequency
768 kHz, IOM-2 mode.
10, 14, 18 57, 6, 61 11, 15, 21 VSSD – Digital ground
21 10 24 VSSA – A na l og ground
28 13, 21 31 VDD – Pow e r suppl y (5 V ± 5%)
23
22
12
11
26
25
XTAL1
XTAL2
I
O
Connection for crystal or
external clock input
Connection for external
crystal.
Left unconnected if external
clock is used.
24
25 14
16 27
28 SR2
SR1 I
IS-Bus Receiver Input
S-Bus Receiver Input
29
30
22
23
32
33
SX1
SX2
O
O
S-Bus Transm itter Output
(positive)
S-Bus Transm itter Output
(negative)
31
32 24
25 34
35 IDP0(DD)
IDP1(DU) I/O
I/O IOM-D ata Port 0 (DD)
IOM-Data Port 1 (DU)
Open drain without internal
pull-up resistor or push-pull
(ADF2:ODS)
1.1 Pin Definitions and Functions (cont'd)
Pin No.
P-DIP-40 Pin No.
P-MQFP-64 Pin No.
P-LCC-44 Symbol Input (I)
Output (O)
Open
Drain (OD)
Function
Semicond uctor Group 14
Features
1.2 Logic Symbol
Figure 1
Logic Symbol of the ISAC®-S TE PSB 2186
IDP0
V
DD
XTAL1 XTAL2
SR2
SX2
SX1
SR1
ITL04472
+ 5 V 0 V 0 V Reset
RST
SSA
VV
SSD
7.68 MHz ±100 ppm
IDP1
FSC
DCL
BCL
SDS
TR = 100 *)
(D0...7) CS (R/W) (DS) INT ALE
*) Terminating resistors only at the far ends of the connection
Clock Frame
Synchronization
S/T
µP
AD0...7 WR RD
(A0...5)
Ω
EAW
1
1
(DD)
(DU)
ΩTR = 100 *)
R
IOM -2
Semicond uctor Group 15
Features
1.3 Functional Block Diagram
Figure 2
Block Diagram of the ISAC®-S TE
ITB05406
FIFO
D-Channel
Handling
B-Channel
Switching Interface
Control
Buffer ISDN
Basic
Access
Layer-1
Functions
P Interface
P
S
-
R
IOM -2
R
IOM
µ
µ
Semicond uctor Group 16
Features
1.4 System Integration
1.4.1 ISDN Applications
The reference model for the ISDN-basic access according to CCITT I series recommendations
consists of
– an exchange and tru nk line termination in the central office (ET, LT)
– a remote network termination in the user area (NT)
– a two-wire loop (U interface) between NT and LT
– a four-wire link (S interface) which connects subscriber terminals and the NT in the user
area as depi ct ed in figure 3.
Figure 3
ISDN-Basic Subscriber Access Architecture
The NT equipment serves as a converter between the U interface at the exchange and the
S interfa ce at the use r premises. The NT may consi st of either an NT1 only or an NT1 to gether
with an NT2 connected via the T interface which is physically identical to the S interface. The
NT1 is a direct transformation between layer 1 of S and layer 1 of U. NT2 may include higher
level functions like multiplexing and switching as in a PBX.
The ISAC-S TE is designed for the user area of the ISDN-basic access, especially for
subscriber terminal equipment with S interfaces. Figure 4 illustrates the application of the
ISAC-S TE.
ITS02314
NT
NT1
NT2 NT1
T
TE
TE
LT ET
SU
ISDN User Area ISDN Central Office
Semicond uctor Group 17
Features
Figure 4
Applications of the ISAC®-S TE (ISDN-Basic Access)
Terminal Applications
The concept of the ISDN basic access is based on two circuit-switched 64 kbit/s B channels
and a message oriented 16 kbit/s D channel for packetized data, signaling and telemetry
information.
Figure 5 shows an example of an integrated multifunctional ISDN-S terminal using the
ISAC-S TE. The ISAC-S TE provides the interface to the bus and separates the B- and
D channels.
The D ch annel, con taining signa ling data and packet sw itched data, is processe d by the LAP D
controller contained in the ISAC-S TE and routed via a parallel µP interface to the terminal
processor. The high level support of the LAPD protocol which is implemented by the
ISAC-S TE allows the use of a low cost processor in c ost sensitive ap plications.
The IOM-2 interfa ce generated b y the ISAC-S TE is used to con nect differen t voice/data (V/D)
application modules:
– sources/sinks for the D channel
– sources/sinks for the B1- and B2 channels.
ITS05407
LT-S
LT-S LT-T
SN
CP
Line
Card
TE(8)
TE(1)
TE(1) S
CP
SN
=
=Switching
Network
Central
Processor
PBX (NT2)
NT1
TU
=
TE(1)
TE(8)
U
S
NT1
Direct Subscriber Access
(point-to-point, short and extended
passive Bus)
-S TEISAC
R
Semicond uctor Group 18
Features
Figure 5
Example of an ISDN®-S TE Voice/Data Terminal
Up to eigh t D -ch an nel co mponents (IC C : IS D N Co mmunicatio n Con tro l l er PEB 2070) ma y be
connected to the D- and C/I (Command/Indication) channels (TIC-bus). The ISAC-S TE and
ICC handle contention autonomously.
Data transfers between the ISAC-S TE and the voice/data modules are done with the help of
the IOM-MONITOR channel protocol. Each V/D module can be accessed by an individual
address. The same protocol enab les the cont rol of IOM-ter minal mod ules and the a llocation of
intercommunication channels inside the terminal. Two intercommunication channels IC1 and
IC2 allow a 2 ×64 kbit/s transfer rate between voice/data modules.
In th e exam ple abo ve (figure 5 ), one ICC is used for data packets in the D channel. A voice
processor is connected to a programmable digital signal processing codec filter via IC1 and a
data encryption module to a data device via IC2. B1 is used for voice communication, B2 for
data communication .
Figure 6 shows the implementation of a ISDN feature phone using the ISAC-S TE and the
Audio Ringing Codec Filter featuring speakerphone (PSB 2165, ARCOFI-SP).
PSB 2186
ICC
PEB 2070 Speech
Processing
DSP-COFI
Data
Encryption HSCX
SAB 8252X
µC
ITD05408
Data Module
Speech Modules
Data Modules
D,C/I B1 IC1 B2 IC2
R
IOM -2
-S TEISAC
R
Semicond uctor Group 19
Features
Figure 6
ISDN-Feature Telephone
1.4.2 M ic roproce ssor Envi ronment
The ISAC-S TE is especially suitable for cost-sensitive applications with single-chip
microcontrollers (e.g. 8048, 8031, 8051). However, due to its programmable micro- processor
interface and non-critical bus timing, it fits perfectly into almost any 8-bit microprocessor
system environment. The microcontroller interface can be selected to be either of the Motorola
type (with control signals CS, R/W, DS) of the Siemens/Intel non-multiplexed bus type (with
contro l signals CS, WR, RD) or of the Siemens/Intel multiplexed address/data bus type (CS,
WR, RD, ALE).
An example how to connect the ISAC-S TE to a Siemens/Intel microcontroller is shown in
figure 7.
ITS05409
PSB 2186
PSB 2165
ARCOFI
Power
Controller
PSB 2120
IRPC
S-Bus
80C51
80C188
LCD
Control
LCD
Display
-SP
R
IOM -2
R
-S TEISAC
R
Semicond uctor Group 20
Features
Figure 7
Connecting the ISAC®-S TE to Siemens/Intel Microcontroller
INT(INTX)
RD
WR
ALE
(PSCX)
AD ... AD0
INT
RD
WR
ALE
CS
AD7 ... AD0
AD0 - AD7
ALE
WR
RD
Latch
A8 - A15
Memory
Common Bus A15 - A0, D7 - D0
ITS05410
PSB 2186
(80C188)
80C51
A15 ... A8
SX2
SR1
SX1
SR2
S
0
+ 5 V
R
IOM -2
-S TEISAC
R
Semicond uctor Group 21
Functional Description
2 Functional Description
2.1 General Functions and Device Architecture
The functional block diagram of the ISAC-S TE is shown in figure 8.
The left-hand side of the diagram contains the layer-1 functions, according to CCITT I series
recommendations:
– S-bus transmitter and receiver
– timin g recove ry and synch r onization by means of digital PLL circuitry
– activation/deactivation
– access to S and Q channels
– handling of D channe l
– test loops
– send single/continuous AMI pulses (diagnostics).
Figure 8
Architecture of the ISAC®-S TE
ITS05411
LAPD
Controller
Status
Command
Register
FIFO
Controller
HDLC
Receiver HDLC
Transmitter
X-FIFOR-FIFO
Interface
Buffer
AMI
BIN
D-CH
Access Control
DPLL Timing
P - Interfaceµ
BIN
AMI Buffer
IDP1 IDP0
XTAL1
XTAL0
SR1
SR2
SX2
SX1
V
SSA DD
V
DCLBCL FSC1 SDS1 AD0 - AD7
A0 - A5&
D0 - D7
Control INT
RST
V
SSD
(DU) (DD)
R
IOM -2
Semicond uctor Group 22
Functional Description
The right-hand side consists of:
– the serial interface logic for the IOM-2 interfac es, with B-channel switching capabilities
– the logic necessary to handle the D-channel messages (layer 2).
The lat ter con sis ts o f an HDL C r ece iver a nd an HD LC tran sm itt er t oget her wit h 64-b yte dee p
FIFO's for efficient transfer of the messages to/from the user's CPU.
In a special HDLC-controller operating mode, the auto mode, the ISAC-S TE processes
protocol handshakes (I- and S frames) of the LAPD (Link Access Procedure on the D channel)
autonomously.
Control and monitor functions as well as data transfers between the user's CPU and the D- and
B channels are performed by the 8-bit parallel µP-in terfac e lo gi c .
The IOM interface allows interaction between layer-1 and layer-2 functions. It implements
D-channel collision resolution for connecting other layer-2 devices to the IOM interface (TIC
bus), and the C/I and MONITOR chan nel protocols (IOM-2) to control p eripheral devices.
The timing unit is responsible for the system clock and frame synchronization.
2.2 Interface and Operating Modes
The ISAC-S TE is configurable for the following application:
– ISDN terminals →TE mode
IOM®-2 Interface Mode (ADF2:IMS=1)
In this mode the IOM interface has the enhanced functionality of IOM-2. B-channel interfacing
is performed directly via the IOM-2 interface.
The ISA C-S TE suppor ts th e IOM-2 term inal mode fram e st ructur e (3 ch annels ) acc ording t o
figure 11 (see chapter 2.3. 1).
The operating mode is shown in tab le 1 .
Table 1
Operating Mode and Functions of Specific Pins of the ISAC®-S PSB 2186 in IOM®-2 Mode
*) synchronized to the S/T interface o:output
Pin No.
P-DIP-40-2 11 12 19
Pin No.
P-LCC-44-1 12 13 22
Pin No.
P-MQFP-64-1 58 59 7
Application DCL FSC1 BCL
TE o:1536 kHz* o:8 kHz* o:768 kHz*
Semicond uctor Group 23
Functional Description
The operating mode in relation to the timing recovery is illustrated in figure 9.
Figure 9
Operating Modes of ISAC®-S TE (IOM®-2)
768 kbit/s
768 kbit/s
768 kHz
8 kHz
8 kHz
1536 kHz
CLOCK MASTER
S
IDP1
IDP0
PSB 2186
DCL FSC1 BCL SDS1
V/D Module
TE Mode, Terminal Timing Mode
ITS05412
(DD)
(DU)
-S TEISAC
R
Semicond uctor Group 24
Functional Description
2.3 IOM®-2 Mode Functions
2.3.1 Basic IOM®-2 Frame Structure
The IOM-2 is a gener alization and en hancement of th e IOM-1. While the ba sic frame structur e
is very similar, IOM-2 offers further capacity for the transfer of maintenance information. In
terminal applications, the IOM-2 constitutes a powerful backplane bus offering
intercommunication and sophi s ticated contro l capabilities for per ipheral mod ule s.
The channel st ructure of the IOM-2 is depicted in figure 10.
Figure 10
Channel Structure of IOM®-2
●The 64-kbit/s channels, B1 and B2, are conveyed in the first two octets.
●The third octet (monitor channel) is used for transferring maintenance information between
the layer-1 functional blocks (SBCX, IECQ) and the layer-2 controller (see chapter 2.3.4).
●The fourth octet (control channel) contains
– two bits for the 16-kbit/s D channel
– four command/in dication bits for controlling activation/deactivation and for additional cont rol
functions
– two bits MR and MX for supporting the handling of the MONITOR channel.
ITD05672
B1 B2 MONITOR D M
RX
M
ΙC/
Semicond uctor Group 25
Functional Description
IOM®-2 TE Frame Structure
The frame is composed of three channels (figure 11):
●Channel 0 contains 144 kbit/s (for 2B+D) plus MONITOR and command/indication channels
for the layer-1 device.
●Channel 1 contains two 64-kbit/s intercommunication channels plus MONITOR and
comman d/indication channels for othe r IOM-2 de vices.
●Channel 2 is used for IOM-bus arbitration (access to the TIC bus). Only the command/
indication bits are used in c hannel 2. See secti on 2.3.6 for details.
Figure 11
Definition of IOM®-2 Channels in Terminal Timing Mode
The IOM-2 signals are:
IDP0, 1 : 768 kbit/s
DCL : 1536-kHz output
FSC1 : 8-kHz output.
In addition, to support standard combos/data devices the following signals are generated as
outputs:
BCL : 768-kHz bit clock
SDS1 : 8-kHz programmable data strobe signal for selecting one or both B/IC
channel(s).
ITD05413
TAD
125
µs
IPD0
(DD) B1 B2 MON0 CI0 IC1 IC2 MON1 CI1D
MR MX MXMR S/G
FSC1
BACMR MXMXMR
D CI1MON1IC2IC1CI0MON0B2B1
(DU)
IPD1
SDS1
CH0 CH1 CH2
A/B
R
IOM -2
R
IOM -2
R
IOM -2
Semicond uctor Group 26
Functional Description
2.3.2 IOM®-2 Interface Connections
Output Driver Selection
The type of the IOM outp ut is se le ctab l e via b i t OD S (AD F 2 re gister). Thus wh en i n active (not
transmitting) IDP0, 1 are either high impedance (ODS=1) or open drain "1" (ODS=0).
Normally the IOM-2 interface is operated in the "open drain" mode (ODS=0) in order to take
advantage of the bus capability. In this case pull-up resistors (1 kΩ–5kΩ) are required on
IDP0 and IDP1.
IOM® OFF Function
In IOM-2 terminal mode (SPCR:SPM=0) the IOM interface can be switched off for external
devices via IOF bit in ADF1 register. If IOF=1, the interface is switched off i.e. DCL, FSC1,
IDP0/1 and BCL are high impedance.
IOM® Direction Control
For test applications, the direction of IDP0(DD) and IDP1(DU) can be reversed during certain
time-slots within the IOM-2 frame. This is performed via the IDC bit in the SQXR register. For
normal operation SQXR:IDC should be set to "0".
Semicond uctor Group 27
Functional Description
IOM® Data Ports in Terminal Mode
In this case the IOM has the 12-byte frame structure consisting of channels 0, 1 and 2 (see
figure 11):
– IDP0 carries the 2B+D channels from the S/T interface, and the MONITOR 0 and C/I 0
channels coming from the S/T controller;
– IDP1 carries the MONITOR 0 and C/I 0 channels to the layer-1.
Channel 1 of the IOM interface is used for internal communication in terminal applications. Two
cases have to be distinguished, according to whether the ISAC-S TE is operated as a master
device (communication with slave devices via MONITOR 1 and C/I 1), or as a slave device
(communication with on e master via MONITOR 1 and C/I 1).
If IDC is set to "0" (master mode):
– IDP0 carries the MONITOR 1 and C/I 1 channels as output to peripheral (voice/data)
devices;
– IDP0 carries the IC channels as output to other devices, if programmed (C×C1 – 0 = 01 in
register SPCR).
If IDC is set to "1" (slave mode):
– IDP1 carries the MONITOR 1 and C/I 1 channels as output to a master device;
– IDP0 carries the IC channels as output to other devices, if programmed (C×C1 – 0 = 01 in
register SPCR).
If required (cf. DIM2-0, MODE register), bit 5 of the last byte in channel 2 on IDP0 is used to
indicate the S-bus state (stop/go bit) and bits 2 to 5 of the last byte are used for TIC-bus access
arbitration (see chapter 2.3.6).
Figure 12 shows the connection in a multifunctional terminal with the ISAC-S TE as a master
(figure 12b) and an ICC as a slave device.
Semicond uctor Group 28
Functional Description
Figure 12a
IOM® Data Ports 0, 1 in Terminal Mode (SPCR:SPM=0)
Layer 1
(SBC)
ITS05414
IDP0
IDP1
IDP0 IDP1
Layer 2
(ICC) Module
Voice/Data
IDP1IDP0 e.g. PEB 2070
(ICC) in Slave
Mode (IDC = 1)
in Master
Mode
(IDC = 0)
C
MON1, C/I1, IC1, IC2
2B + D, C/I0, MON0, S/G, TIC
Master Slave
S/T
Interface
DU
DD
µ
(DD) (DU)
IDP1
IDP0
(DD)
(DU)
-S TEISAC
R
R
IOM -2 Interface
-S TEISAC
R
Semicond uctor Group 29
Functional Description
Figure 12b
ITD05415
TIC-Bus
IPD0
(DD) B1 B2 MON0 CI0 IC1 IC2 MON1 CI1D
MR MX MXMR S/G
BACMR MXMXMR
D CI1MON1IC2IC1CI0MON0B2B1
(DU)
IPD1
CH0 CH1 CH2 A/B
TAD
S/T IC Transmit
if Progr.
Layer Layer1 2 Layer 2
2Layer12 LayerLayer if Progr.
IC Receive
S/T
S/T IC Transmit
if Progr.
Layer Layer21
Layer 2
2Layer
21 LayerLayer if Progr.
S/T
TAD
CH2CH1CH0
IPD1
(DU) B1 B2 MON0 CI0 IC1 IC2 MON1 CI1D
MR MX MXMR BAC
MR MXMXMR
D CI1MON1IC2IC1CI0MON0B2B1
(DD)
IPD0
TIC-Bus
A/BS/G
R
IOM -2 IOM
R
-2
R
IOM -2 -2IOM
R
IOM
R
-2
-2IOM
R
IOM
R
-2
IOM
R
-2
(a) Mast er Mode (IDC = 0)
(b) Sla ve Mode (ID C = 1)
Semicond uctor Group 30
Functional Description
2.3.3 µP Access to B and IC Cha nnels
The microprocessor can access the B and IC (intercommunication) channels at the IOM-2
interface by reading the B1CR/B2CR or by reading and writing the C1R/C2R registers.
Furthermore it is possible to loop back the B channels from/to the S/T interface or to loop back
the IC channels from/to the IOM-2 interface without µP intervention.
These access and switching functions are selected with the channel connect bits (CxC1,
CxC0) in the SPCR register (table 2, figure 13).
External B-channel sources (voice/data modules) connected to the IOM-2 interface can be
disconnected with the IOM off function (ADF1:IOF) in order to not disturb the B-channel access
(see figure 13).
If the B-channel access is used for transferring 64-kbit/s voice/data information directly from
the µP port to t he ISDN S/T interf ace, the access can b e synchroni zed to the IOM inter face by
means of a synchronous transfer interrupt programmed in the STCR re gister .
Table 2
µP Access to B/IC Channels (IOM®-2)
Note: x=1 for channel 1 or 2 for channel 2
The general sequence of operations to access the B/IC channels is:
C×C1 ApplicationsC×C0
Read Write Read
0 B×monito ring, IC×monitoring0 IC×– B×
0 B×monitoring, IC×looping from/to IOM-21 IC×IC×B×
1 B×access from/to S0;
transmission of a constant valu e in
B×channel to S0
0 – B×B×
1 B×looping from S0;
transmission of a variable pattern in
B×channel to S0
1 B×B×–
C×R B×CR
IOM-2
–
IC×
B×
B×
OutputC×Rto
(set conf ig ur at i on re gi ste r SPC R )
Program synchronous interrupt (ST0)
SIN – >Read register (B×CR, C×R)
(write register)
Acknowledge SIN (SC0)
Semicond uctor Group 31
Functional Description
Figure 13
Principle of B/IC-Channel Access
IDP0
IDP1
Layer-1
Functions
S/T Interface
ITS05416
P
Interface
ADF1 : IOF
Register: C1R/C2R
B1CR/B2CR SPCR
µ
(DD)
(DU)
-S TEISAC
R
R
IOM -2 Interface
R
(IOM off)
Semicond uctor Group 32
Functional Description
Figure 14
Access to B and IC Channels in IOM®-2 Terminal Mode
(a) SPCR:C ×C1, C×C0 = 00
B×monitoring, IC×monitoring (SQXR:IDC=0)
BxCR
Layer-1
Functions
S/T Interface
ITS05417
P
Bx
CxR
ICx
µ
IDP1
IDP0
(DD)
(DU)
R
IOM -2 Interface
ITD05402
B1 B2 IC2IC1 B1 B2 IC2IC1
IC1 IC2B2B1IC1 IC2B2B1
B1CR
B2CR C1R
C2R
IDPO
(DD)
(DU)
IDP1
ST0 SC0 = 1
FSC
Semicond uctor Group 33
Functional Description
(b) SPCR:C×C1, C×C0 = 01
B×monitoring, IC×looping (SQXR:IDC=0)
BxCR
ITS05418
P
ICxBx
CxR
S/T Interface
Layer-1
Functions
µ
IDP1
IDP0
(DD)
(DU)
R
IOM -2 Interface
ITD05403
B1 B2 IC2IC1 B1 B2 IC2IC1
IC1 IC2B2B1IC1 IC2B2B1
B1CR
B2CR C1R
C2R
IDPO
(DD)
(DU)
IDP1
ST0
FSC
SC0 = 1
Semicond uctor Group 34
Functional Description
(c) SPCR:C ×C1, C×C0 = 10
B×access from/to S/T
transmission of constant value to S/T
BxCR
IDP0
IDP1
ITS05419
P
Bx
CxR
Bx
S/T Interface
Layer-1
Functions
µ
(DD)
(DU)
R
IOM -2 Interface
ITD05404
B1 B2 IC2IC1 B1 B2 IC2IC1
IC1 IC2B2B1IC1 IC2B2B1
B1CR
B2CR
C1R
C2R
IDPO
(DD)
(DU)
IDP1
ST0
FSC
SC0 = 1
Semicond uctor Group 35
Functional Description
(d) SPCR:C×C1, C×C0 = 11
B×looping from/to S/T
transmission of variable pattern to S/T
CxR
ITS05420
P
BxBx
µ
S/T Interface
Layer-1
Functions IDP1
IDP0
(DD)
(DU)
R
IOM -2 Interface
ITD05405
B1 B2 IC2IC1 B1 B2 IC2IC1
IC1 IC2B2B1IC1 IC2B2B1
B1CR
B2CR
IDPO
(DD)
(DU)
IDP1
ST0
FSC
SC0 = 1
Semicond uctor Group 36
Functional Description
2.3.4 MONITOR Channel Handling
In IOM-2 mode, the MONITOR channel protocol is a handshake protocol used for high speed
informa tion exchang e betwee n the ISAC-S TE and other devices, in M ONITOR chan nel "0" or
"1" (see figure 1 1). In the non-TE mode, only one MONITOR channe l is available ("MONITO R
channel 0").
The MONITOR channel protocol is necessary:
●For programming and controlling devices attached to the IOM. Examples of such devices
are: layer-1 transceivers (using MONITOR channel 0), and peripheral V/D modules that do
not need a parallel microcontroller interface (MONITOR channel 1), such as the Audio
Ringing Codec Filte r PSB 2165.
●For data exchange between two microcontroller systems attached to two different devices
on one IOM-2 backplane. Use of the MONITOR channel avoids the necessity of a dedicated
serial communication path between the two systems. This greatly simplifies the system
design of terminal equipment (figure 17 ).
Note: There is normally no necessity for monitor channel operations over "MONITOR
channel 0" since the internal layer-1 part of the ISAC-S TE does not support this
function. The implemented MONITOR handler can however be used with external
layer-1 transceivers in case only the ICC part of the ISAC-S TE is used (ADF1:TEM).
Semicond uctor Group 37
Functional Description
Figure 15
Examples of MONITOR Channel Applications in IOM®-2 TE Mode
The MONITOR channel operates on an asynchronous basis. While data transfers on the bus
take place synchronized to frame sync, the flow of data is controlled by a handshake procedure
using the MONITOR Channel Receive (MR0 or 1) and MONITOR Channel Transmit (MX0 or
1) bits. For example: data is placed onto the MONITOR channel and the MX bit is activated.
This data will be transmitted repeatedly once per 8-kHz frame until the transfer is
acknowledg ed via the MR bit.
The microprocessor may either enforce a "1" (idle) in MR, MX by setting the control bit MRC1,
0 or MXC1, 0 to "0" (MONITOR Control Register MOCR), or enable the control of these bits
internal ly b y the ISAC-S TE a ccordin g to the M ONITOR ch anne l protocol . Thu s, befo re a data
exchange can begin, the control bit MRC(1, 0) or MXC(1, 0) should be set to "1" by the
microprocessor.
The MONITOR channel protocol is illustrated in figure 16. Since the protocol is identical in
MONITOR c hanne l 0 and MONITOR chann el 1 ( availabl e in TE mode on ly), th e ind ex 0 or 1
has been left out in the illustration.
The relevant status bits are:
In addition, the status bit:
MONITOR Channel Active MAC (MAC0, MAC1)
indi cates whether a tran smission is in progre ss (register: STAR).
ITS05421
V/D Module
PSB
ARCOFI
ARCOFI 2160
-SP PSB 2165
2110ITAC PSB
V/D Module
Cµ µC
Control (MONITOR1)
Data Communication
(MONITOR1)
PSB 2186
R
IOM -2
R
-S TEISAC
R
R
R
MONITOR Channel Data Received MDR (MDR0, MDR1)
MONITOR Channel End of Reception MER (MER0, MER1)
for the reception of MONITOR data, and
MONITOR Channel Data Acknowledged MDA (MDA0, MDA1)
MONITOR Channel Data Abort MAB (MAB0, MAB1)
for the transmission of MONITOR data (register: MOSR)
Semicond uctor Group 38
Functional Description
Figure 16
MONITOR Channel Protocol (IOM®-2)
ITD00870
MON MX
Transmitter
MR
11FF
FF 1 1
ADR 0 1
00DATA1 01DATA1
ADR 0 0
DATA1 0 1
DATA1 0 0
00DATA2 01DATA2
DATA2 0 1
DATA2 0 0
FF 1 0
FF 1 0
FF 1 1
FF 1 1
Receiver
MXE =1
ADR=MOX
MXC = 1
1=MAC
MOX = DATA1
MDA Int.
MDA Int.
DATA2=MOX
MDA Int.
0=MXC
0=MAC
MDR Int.
RD
MRC
MOR
=1( = ADR )
DATA1 )( =MORRD
MDR Int.
MDR Int.
RD MOR ( = DATA2 )
MRC = 0
MER Int.
125 s
PPµµ
µ
Semicond uctor Group 39
Functional Description
Before starting a transmission, t he microprocessor should verify that the transmitter is inactive,
i.e. tha t a possib le previo us transmi ssion has bee n termin ated. This is indicat ed by a "0 " in the
MONITOR Channel Active MAC status bit.
After ha ving writt en the MONITOR Data Transmit ( MOX) reg ister, the micropro cessor sets t he
MONITOR Tr ansmit Co ntrol bi t MXC to "1". Thi s enabl es the MX bi t to go active (0), i ndicating
the presence of valid MONITOR data (contents of MOX) in the corresponding frame. As a
result, the receiving device stores the MONITOR byte in its MONITOR Receive MOR register
and generates an MDR interr upt status.
Alerted by the MDR interrupt, the microprocessor reads the MONITOR Receive (MOR)
register. When it is ready to accept data (e.g. based on the value in MOR, which in a point-to-
multipo int applicat ion might be th e address of the desti nation device), i t sets the MR contro l bit
MRC to "1" to enable the receiver to store succeeding MONITOR channel bytes and
acknowledge them according to the MONITOR channel protocol. In addition, it enables other
MONITOR channel interrupts by setting MONITOR Interrupt Enable to "1".
As a resul t, the first MONITOR byte is acknowledged b y the receivin g device settin g the MR
bit to "0". This causes a MONITOR Data Acknowledge MDA-interrupt status at the transmitter.
A new MONITOR data byte can now be written by the microprocessor in MOX. The MX bit is
still in the active (0) state. The tran smitter indicates a new byte in the MONITOR channe l by
returning the MX bit active after sending it once in the inactive state. As a result, the receiver
stores the MONITOR byte in MOR and generates a new MDR-interrupt status. When the
microprocessor has read the MOR register, the receiver acknowledges the data by returning
the MR bit active after sending it once in the inactive state. This in turn causes the transmitter
to generate an MDA-interrupt status.
This "MD A interrupt – write dat a – MDR interr upt – read da ta – MDA inte rrupt" ha ndshake i s
repeated as long as the transmitter has data to send. Note that the MONITOR channel protocol
imposes no maximum reaction time s to the microprocessor.
When the last byte has been acknowledged by the receiver (MDA-interrupt status), the
microprocessor sets the MONITOR Transmit Control bit MXC to "0". This enforces an inactive
("1") state in the MX bit. Two frames of MX inactive signifies the end of a message. Thus, a
MONITOR C hannel End o f Reception MER-interr upt status is generat ed by the recei ver when
the MX bit is received in the inactive state in two consecutive frames. As a result, the
microprocessor sets the MR control bit MRC to 0, which in turn enforces an in active state in
the MR bit. This marks the end of the transmission, making the MONITOR Channel Active
MAC bit return to "0".
During a transmission process, it is possible for the receiver to ask a transmission to be
aborte d by sending an inac tive MR bit value in two con secutive fr ames. This is effecte d by the
microprocessor writing the MR control b it MRC to "0 ". An a bo rted tran smission is indica ted by
a MONITOR Channel Data Abort MAB-interrupt status at the transmitter.
Semicond uctor Group 40
Functional Description
2.3.5 C/I-Channel Handling
The comm an d/ind i cati o n cha nn el carr i es rea l- tim e st atus inform ation betw e en t he ISAC - S TE
and another device connected to the IOM.
1) One C/I channel (called C/I0) conveys the commands and indications between the layer-1
and the layer-2 parts of the ISAC-S TE. It can be accessed by an external layer-2 device
e.g. to control the layer-1 activation/deactivation procedures. C/I0 channel access may be
arbitrated via the TIC bus access protocol. In this case the arbitration is done in C/I
channel 2 (see figure 11).
The C/I0 chan nel is accessed via register CIR0 (in receive direction , layer-1 to layer-2) and
register CIX0 (in transmit direction, layer-2 to layer-1). The C/I0 code is four bits long.
A listing and explanation of th e layer - 1 C/I cod es can be foun d in chapter 3.4.
In the receive direction, the code from layer-1 is continuously monitored, with an interrupt
being g ene rate d anytime a ch an ge occ ur s ( IS TA :CISQ). A n ew co de m ust b e fou nd in tw o
conse cutiv e IOM frame s to b e con sidere d valid and to trig ger a C/I code ch ange in terr upt
status (double last look criterion).
In the transmit direction, the code written in CIX0 is continuously transmitted in C/I0.
2) A second C/I channel (called C/I1) can be used to convey real time status information
between the ISAC-S TE and various non-layer-1 peripheral devices e.g. PSB 2160
ARCOFI. The channel consists of six bits in each d i rection (see figure 11).
The C/I1 channel is accessed via registers CIR1 and CIX1. A change in the received C/I1
code is indi cated by an interrupt status with out double last look cr iterion.
Semicond uctor Group 41
Functional Description
Figure 17
Applications of TIC Bus in IOM®-2 Bus Configuration
2.3.6 TIC-Bus Access
In IOM-2 interface mode the TIC-bus capability is only available in TE mode. The arbitration
mechanism implemented in the last octet of IOM channel 2 of the IOM allows the access of
external communication controllers (up to 7) to the layer-1 functions provided in the ISAC-S TE
and to the D channel. (TIC bus; see figure 17). To this effect the outputs of the controllers
(ICC:ISDN Communication Controller PEB 2070) are wired-or-and connected to pin IDP1. The
inputs of the ICCs are connected to pin IDP0. External pull-up resistors on IDP0/1 are required.
The arbitration mechanism must be activated by setting MODE:DIM2–0=001 (see
chapter 4.1.7).
An access request to the TIC bus may either be generated by software (µP access to the C/I
ITS05673
D-Channel
Telemetry/
Packet
Communication
ICC (7)
(1)ICC
with D-Channel
Communication
Voice/Data
B-Channel
Signaling
Signaling
B-Channel
Voice/Data
Communication
with D-Channel CCITT
S-Interface
µP
TIC-Bus
R
IOM -2
-S TEISAC
R
Semicond uctor Group 42
Functional Description
channel) or by the ISAC-S TE itself (transmission of an HDLC frame). A software access
request to the bus is effected by setting the BAC bit (CIX0 register) to "1".
In the case of an access request, the ISAC-S TE checks the Bus Accessed-bit (bit 5 of IDP1
last octet of CH2, see figure 18) for the status "bus free", which is indicated by a logical "1". If
the bus is free, the ISAC-S TE transmits its individual TIC-bus address programmed in the
STCR register. The TIC bus is occupied by the device which sends its address error-free. If
more than one device attempt to seize the bus simultaneously, the one with the lowest address
values wins.
Figure 18
Structure of Last Octet of CH2 on IDP1 (DU)
When the TIC bus is seized by the ISAC-S TE, the bus is identified to other devices as
occupied via the IDP1 C/I Bus Accessed-bit state "0" until the access request is withdrawn.
After a successful bus access, the ISAC-S TE is automatically set into a lower priority class,
that is, a new bus access cannot be performed until the status "bus free" is indicated in two
successive frames.
If none of the devices connected to the IOM interface request access to the D- and C/I
channels, the TIC-bus address 7 will be present. The device with this address will therefore
have access, by default, to the D and C/I channels.
Note: Bit BAC (CIX0 register) should be reset by the µP when access to the C/I channels is
no more requ ested, to grant other devic es access to the D - and C/I channels.
The availability of the S/T interface D channel is indicated in bit 5 "Stop/Go" (S/G) of the IDP0
last octet of C/I channel (figure 19).
S/G = 1 : stop
S/G = 0 : go
ITD02575
D CI1MON1IC2IC1CI0MON0B2B1
MR
MX MX
MR TAD
BAC
TAD
BAC
102
TIC-Bus Address
Bus Accessed (TAD 2-0)
(’1’ no TIC-Bus Access)
Semicond uctor Group 43
Functional Description
Figure 19
Structure of Last Octet of CH2 on IDP0 (DD)
The st op/go bi t is available to othe r layer- 2 devices connected to the IO M to determine if they
can access the S/T bus D channel.
The available busy bit is not influenced by the ISAC-S TE.
ITD05422
D CI1MON1IC2IC1CI0MON0B2B1
MR
MX MX
MR
S/G A/B
A/BS/G
STOP/GO Available/Blocked
Semicond uctor Group 44
Functional Description
2.4 Layer-1 Functions for the S/T Interface
– line transceiver functions for the S/T interface according to the electrical specifications of
CCITT I.430;
– conversion of the frame structure between IOM and S/T interface;
– conversion from/to binary to/from pseudo-ternary code;
– level detect;
– S/T-timing generation using IOM timing synchronous to system, or vice versa;
– D-channel access control and priority handling;
– activation/deactivation procedures, triggered by primitives received over the IOM C/I
channel or by INFO's received from the line;
– frame alignment;
– execution of test loops.
For a block d i agram, se e figure 8.
The wiring configurations in user premises, in which the ISAC-S TE can be used are illustrated
in figure 20.
Semicond uctor Group 45
Functional Description
Figure 20
Wiring Configurations in User Premises
TE
TR TR
TRTR
LT-T
Point-to-Point
Configurations
SBC
LT-S
NT
NT
LT-S
SBC
TR TR Short Passive
Bus
ITS05423
TE1 TE8
1)
km1.5
m10
10 m
m150
TE8TE1
Passive Bus
Extended
TRTR SBC
LT-S
NT
m35
TR:Terminating Resistor
-S 15 dB at 96 kHz.The maximum line attenuation toleratet by the ISAC
1)
-S TEISAC
R
-SISAC
R
ISAC -S
R
R
IOM -2
ISAC -S
R
-S TEISAC
R
-S TEISAC
R
IOM -2
R
R
-S TEISAC
R
-S TEISAC
R
ISAC -S
R
-2IOM
R
150 m
km1.5
1)
_
<
_
<
_
<
_
<
_
<
_
<
_
_
<
Semicond uctor Group 46
Functional Description
2.4.1 S/T Interface
According to CCITT recommen dation I.430 p seudo-tern ary encoding w ith 100% pul se width is
used on the S/T interface. A logical "1" corresponds to a neutral level (no current), whereas
logic al "0" ’s ar e enco ded as altern ating po siti ve and ne gati ve puls es. An examp le is sho wn in
figure 21.
Figure 21
S/T-Interface Line Code
One frame consists of 48 bits, at a nominal bit rate of 192 kbit/s. Thus each frame carries two
octets of B1, two octets of B2, and four D bits, acco rding to the B1+ B2+D structur e defined for
the ISD N-basic access (t otal useful data rate: 144 kbit/s). Fr ame begin is marked using a code
violation (no mark inversion). The frame structures (from network to subscriber, and subscriber
to network) are shown in figure 22.
Figure 22
Frame Structure at Reference Points S and T (CCITT I.430)
Note: Dots demarcate those parts of the frame that are independently DC-balanced.
ITD00322
01001100011
V+
0V
V-
ITD02330
DL.
0
1
0
L.F B1 EDAF N
A
B2 EDM B1 SDEB2E DL. F L.
48 Bits in 250 µs
L.FL.DL.B2L.DL.B1L.DL.B2
A
L.FL.DL.B1FL.L.D
F = Framing Bit
DC Balancing Bit=L D-Channel Bit=D D-Echo-Channel Bit=E Auxiliary Framing Bit or Q-Bit=F
A
Bit set to a Binary Value N=N
B1 = Bit within B Channel
B2 =
A = Bit used for Activation
S = Subchannel SC1 through SC5 bit position
M = Multiframing Bit
Bit within B Channel
t
F
A
=
1
2
2 Bits Offset
NT TE
NTTE 0
1
0
Semicond uctor Group 47
Functional Description
2.4.2 Analog Functions
For both receive and transmit direction, a 2:1 transformer is used to connect the ISAC-S TE
transceiver to the 4 wire S/T interface. The corrections are shown in figure 23.
Figure 23
ISAC-S TE External S-Interface Circuitry
The full-bauded pseudo-ternary pulse shaping is achieved with the integrated transmitter
which is re alized as a curr ent limited voltage sou rce. A voltag e of 2.1 V is delive red betwee n
SX1-SX2, which yields a current of 7.5 mA over 280 Ω.
The recei ver is desig ned as a threshol d detector with ad aptively swit ched threshold level s. Pin
SR1 delivers 2.5 V as an output, which is the virtual ground of the input signal on pin SR2.
The external transformer of ratio 2:1 is needed in both receive and transmit direction to provide
for isolation and transform voltage levels according to CCITT recommendations.
The equivalent circuits of the integrated receiver and transmitter are shown in figure 24.
Figure 24
Equivalent Internal Circuits of Receiver and Transmitter Stages
ITS05640
+ 5 V
10 µF
GND
2 : 1
2 : 1
Pair
Pair
V
DD
SX1
SX2
SR1
SR2
V
SSD
V
SSA
PEB 2086
Transmit
Receive
ISAC-S TE
PSB 2186
ITS05939
SR1
k40
+
-
Ω
SR2
Ω50 k
Ω40 k
50 kΩ
2.5 V
-S TE PSB 2186ISAC
R
ITS05940
SX1
SX2
2.1
2.1
13.4
¾
ΙmA
V
V
ISAC
R
-S TE PSB 2186
switch position shown for negative pulses
Semicond uctor Group 48
Functional Description
Symmetrical S-Bus Receiver
The S-bus receiver of the PSB 2186 is a symmetrical one. This results in a simplification of the
external circuitry and PCB layout to meet the I.430 receiver input impedance specification.
2.4.3 S/T-Interface Circuitry
In order to comply to the physical requirements of CCITT recommendation I.430 and
conside rin g the na tion al re qui rements conce rning over volt age pr otecti on an d ele ctrom agnet ic
compatibility (EMC), the ISAC-S TE needs some additional circuitry.
Useful hint s how to de sign such i nter face circu itry ar e conta ined on the App licati on Note “S/T-
interface circuitry using the PEB 2080 SBC or PEB 2085 ISAC-S (12/89)”.
The transmi tter of the PSB 2186 ISAC-S TE is iden tical to that of bo th the PEB 2080 SBC and
PEB 2085/ISAC-S, hence, the line interface circuitry should be the same (figure 25). The
external resistors (20 … 40 Ω) are required in order to adjust the output voltage to the pulse
mask (n ominal 750 mV according to CCI TT I.430, t o be test ed with the command “S SZ”) on
the one hand and in order to meet the output impedance of minimum 20 Ω (transmi ssion of a
binary zero according to CCITT I.430, to be tested with the command “SCZ“) on the other
hand.
Figure 25
External Transmitter Circuitry
The receiver of the PSB 2186 ISAC-S TE is symmetrical as opposed to both PEB 2080 SBC
and PEB 2085 ISAC-S. Thus two resistors of 10 kΩ must be plac ed in series to t he receiver
inputs.
In order to protect the ISAC-S inputs and comply to impedance requirements performed
without pow e r sup ply (96-kHz test) , the 10 kΩ tester is split-up.
A 1.8 kΩ resistor protects the device inputs, while the 8.2 kΩ resistors limit the maximum
current in impedance tests.
ITS04475
GND
2 : 1
Overvoltage
Protection S-Bus
Connector
SX1
SX2
20...40
DC Point
V
DD
Ω
2.7 V
PSB 2186
20...40 Ω
-S TEISAC
R
Semicond uctor Group 49
Functional Description
Figure 26
External Receiver Circuitry
2.4.4 S/T Interface Pre-Filter Compensation
To compensate for the extra delay introduced into the received signal by a filter, the sampling
of the receive signal can be delayed by programming bits TEM and PFS in the ADF1 register
as shown in table 3 . Note that setting TEM to "1" and PFS to "0" has the effect of completely
disabling layer-1 functions, for test purposes (see section 2.6).
Table 3
TEM/PFS Function Table
This delay compensation might be necessary in order to comply with the "total phase deviation
input to output" requirement of CCITT recommendation I.430 which specifies a phase
deviation in the range of – 7% to + 15% of a bit period.
ITS04474
GND
2 : 1
Overvoltage
Protection S-Interface
Connector
SR1
SR2
8.2 k
DC Point
k8.2
V
DD
Ω
1.8 k
Ω
k1.8
ΩΩ
47 pF
pF47
PSB 2186
-S TEISAC
R
TEM PFS Effect
0 0 No pre- filter (0 delay)
0 1 Pre-filter del ay compe nsation 520 ns
1 1 Pre-fil ter delay com pe nsat i on 910 ns
1 0 Test mode (layer-1 disabled)
Semicond uctor Group 50
Functional Description
2.4.5 Receiver Functions
2.4.5.1 Receive Signal Oversampling
In order to additionally reduce the bit error rate in severe conditions, the ISAC-S TE performs
oversamplin g of the received signal and uses majori ty decision logic.
As illustrated in figure 27 , each received bit is sampled 29 times at 7.68-MHz clock intervals
inside the estimated bit window. The samples obtained are compared against a threshold
VTR1 or VTR2 (see section: Adaptive Receiver Characteristics).
If at least 16 samples have an amplitude exceeding the selected threshold, a logical "0" is
considered to be detect ed, otherwise a logic al "1" (no signal) is co nsider ed detected.
Figure 27
S/T-Receive Signal Oversampling
ITD02361
27 30 31
2421 22 26 2920 23
11
81714
9
712 191813 15 16
14
3
5
6
233 353432 40393837362825
V
SR2 SR1
V
V
TR1 TR2
V
Derived 192-kHz Receive Bit Period
10
-
or
0 V
Semicond uctor Group 51
Functional Description
2.4.5.2 Adaptive Receiver Characteristics
The int eg ra ted r ece iv er u s es an ad aptively swi tch ed th re sho ld d ete ctor . The d ete ctor co ntrols
the switching of the receiver between two sensitivity levels. The hysteresis characteristics of
the receiver ar e shown in figure 28.
Figure 28
Switching of the Receiver between High Sensitivity and Low Sensitivity
ITD00774
+ 225 mV
mV- 225
V0
0Logical
Logical 0
1Logical
V
SR2
-
SR1
V V
SR1
-
SR2
V
Logical 1
0Logical
Logical 0
0V
- 375 mV
mV+ 375
State 1
High Sensitivity
with
TR1
V
± 225 mV==mV± 375
V
TR2
withLow Sensitivity
2State
12
max
V
>1Vor V-1<
V
max
in two Consecutive Frames
max
V
> -750 mVandmV750<
V
max
max
V
1V750 mV
V
SR1
-
SR2
V
V
TR1 TR2
V
=
=
=
max
VV
SR2
-
SR1
V
Input Voltage
Threshold Voltages of the Receiver Threshold Detector
Maximum Value of during one Frame
_
<
_
<<
_
<
_
750
max
_
<
_
mV
V
<
_
<<
_
V1
Semicond uctor Group 52
Functional Description
2.4.5.3 Level Detection P o wer Down
In power down state, (see chapter 3.3.1) only an analog level detector is active. All clocks,
including the IOM interface, are stopped. The data lines are "high", whereas the clocks are
"low".
An activation initiated from the exchange side (Info 2 on S bus detected) will have the
cons equence that a clock s ignal is pro vided automatically.
From the terminal side an activation must be started by setting and resetting the SPU bit in the
SPCR register (see c hapter 4).
2.4.6 Timing Recovery
The transmit an d receive bit clocks are derived, with the help of the DPLL, from the S-interf ace
receive data stream. The received signal is sampled several times inside the derived receive
clock period, and a majority logic is used to additionally reduce bit error rate in severe
conditions (see chapter 2.4.5). The transmit frame is shifted by two bits with respect to the
received frame.
The output clocks (DCL, FSC1 etc.) are synchronous to the S-interface timing.
Figure 29
Clock System of the ISAC®-S TE in TE Mode
ITS05425
DCL
FSC
PLL
TE Mode
BCL
Semicond uctor Group 53
Functional Description
2.4.7 Activation/Deactivation
An incorporated finite state machine controls ISDN layer-1 activation/deactivation according to
CCITT (see chapter 3.4).
Loss of Synchronization / Resynchronization
The following section describes the behaviour of the PSB 2186 in respect to the CTS test
procedures for frame alignment.
Setting of the ISAC-S TE
The ISAC-S TE needs to be programmed for multiframe operation with the Q-bits set to ’1’.
STAR2: MULT = 0
SQXR:SQ X1-4 = 111 1B (xFH)
2.4.7.1 FAinfA_1fr
This test checks if no loss of frame alignment occurs upon a receipt of one bad frame. The
pattern for the bad frame is defined as IX_96 kHz. This pattern was revised so that a code
violation is generated at the begin of the next info 4 frame.
Device Settings Result Comments
PSB 2186 V1.1 none Pass
ITD05898
Info 4
Info 3 3Info
4Info
Info 3
IX_96 kHz
3Info
Info 4
Code Violation
Semicond uctor Group 54
Functional Description
2.4.7.2 FAinfB_1fr
This test uses a frame which has no framing and balancing bit.
2.4.7.3 FAinfD_1fr
This test uses a frame which remains at binary ’1’ until the first code violation in bit 16. Since
it is specified, that a terminal should mirror the received FA-bit in the transmitted FA-bit, a frame
is generated by the IUT which will not generate a second code violation. The pattern for a
correct i3_BASIC frame states that the FA-bit may have any value.
Device Settings Result Comments
PSB 2186 V1.1 none Pass
Device Settings Result Comments
PSB 2186 V1.1 none Pass
ITD05899
Info 4
Info 3 3Info
4Info
Info 3
I4_BASIC IX_I4noflag
3Info
Info 4
Code Violation
ITD05900
Info 4
Info 3 3Info
4Info
Info 3 with
Info 3
Info 4
A
F1
=
A
F1
=
Semicond uctor Group 55
Functional Description
2.4.7.4 FAinfA_kfr
This test uses a number of IX_96 kHz frames to check the loss of synchronization.
2.4.7.5 FAinfB_kfr
This test uses a number of IX_I4noflag frames to check the loss of synchronization.
Device Settings Result Comments
PSB 2186 V1.1 n = 2 Pass
Device Settings Result Comments
PSB 2186 V1.1 n = 2 Pass
ITD05901
Info 4
Info 3 3Info
4Info
Info 3
IX_96
I3_SFAL 0Info
kHz kHzIX_96 kHzIX_96
ITD05902
Info 4
Info 3 3Info
4Info
Info 3
I4_BASIC IX_I4noflag IX_I4noflag IX_I4noflag
I3_SFAL 0Info
Semicond uctor Group 56
Functional Description
2.4.7.6 FAinfD_kfr
This t est use s a numb er of I X_I4vo il16 fr ames to c heck th e loss of sync hroniza tion. The fir st
Info 3 f rame with th e FA-bit set to one looks like a i3_SFAL frame but it is a correct info 3 frame
since the receiver stays synchronous (see FAinfD _1fr).
2.4.7.7 FAregain
This test uses I4_BASIC frames to regain the frame alignment. The protocol tester evaluates
the difference between sending the first info 4 frame until a complete info 3 frame has been
received. This period is considered as ’m+1’. ’m’ must be specified before the test is started.
The PSB 2186 achieves synchronization after 5 or 6 frames. The actual value depends on
internal timing conditions which can not be influenced from extern. This is a result of changes
that were made to handle the iXvoil16 test case correctly. The info 4 pattern generates the
second code violation at the position of the FA-bit. Around that bit position, the state machine
changes i ts sta tes . As a r e sult of tha t ove rla p, t he i n fo 3 fram e i s tr an smitted after 5 fr ames o r
one frame later.
Device Settings Result Comments
PSB 2186 V1.1 n = 2 Pass
Device Settings Result Comments
PSB 2186 V1.1 m = 5 or 6 Pass
ITD05903
Info 4
Info 3 3Info
4Info
I3_SFAL
A
F1
=
with3Info
F=
A
1
F=
A
1
ITD05904
Info X 4Info
12
Info 4
3
Info 4
4
Info 4
5
Info 4
6
Info 4
7
Info 4
3Info
Info 3
Semicond uctor Group 57
Functional Description
2.4.8 D-Channel Access
The D channel is submitted to the D-channel access procedure according to CCITT
recommendation I.430.
The D-channel access procedure according to CCITT I.430 including priority management is
fully implemented in the ISAC-S:
If collision detection is programmed (MODE:DIM2-0) , a collisio n is detected if either an echo
bit of "0" is recognized and a D bit of "1" was generated, or an echo bit of "1" is recognized and
a D bit of "0" was generated. When this occurs, D-channel transmission is immediately
stopped, and the echo channel is monitored to enable a subsequent D-channel access to be
attempted.
Stop/Go Bit
As the collision resolution is performed by the layer-1 part of the device, an information about
the D-channel sta tus ("ready" or "busy") must be sent back to the laye r-2 part to control HDLC
transmission. For this goal a Stop/Go (S/G) bit is transmitted over the IOM interface to the
layer-2 device.
The S/G bit is transmitted in bit 90 of an IOM-2 frame (12-byte structure) (see figure 19).
A logic al "1 " of th e S/G bit indi cate s a col lisio n on th e S bu s. By s endin g the S /G b it a log ical
"0" to the layer-2 controller in anticipation of the S bus D channel "ready"-state, the first valid
0 bits will emerge from the layer-1 part at exactly that moment an access is becoming possible.
Selection of D-Channel Access Mode
For proper operation of the D-channel access procedure, the ISAC-S TE must be programmed
via the MODE (see chapter 4.1.7) register to evaluate the stop/go bit. This is achieved by
setting MODE:DIM2-0 to 001 or 011.
Selection of the Priority Class
The priori ty class (pri ority 8 o r priority 1 0) is select ed by tr ansferr ing the a ppropri ate activa tion
command via the Command/Indicate (C/I) channel of the IOM interface to the layer-1
controller. If the activation of the S interface is in itiated by a TE, the priority class is selected
implicitly by the choice of the activation command. If the S-Interface is activated from the NT,
an activation command selecting the desired priority class should be programmed at the TE
on reception of the activation indication (AI8). In the activated state, the priority class may be
changed whenever required simply by programming the respective activation request
command (AR8 or AR10). The following table summarizes the C/I codes used for setting the
priority classes:
Semicond uctor Group 58
Functional Description
Table 4
Priority Commands/Indications
2.4.9 S- and Q-Channel Access
Access to the received/transmitted S- or Q channel is provided via registers. As specified by
CCITT I.430, the Q bit is transmitted from TE to NT in the position normally occupied by the
auxiliary framing bit (FA) in one frame out of 5, whereas the S bit is transmitted from NT to TE
in a spare bit, see figure 22.
The functions prov ided by the ISAC-S ar e:
– Synchronization to the received 20 frame multiframe by means of the received M bit pattern.
Synch ronism is a chieved when th e M bit has been correctly receive d during 20 conse cutive
frames starting from frame number 1 (table 5).
– When synchronism is ach ieved, the four received S bits in frames 1, 6, 11 and 16 are stored
as SQR1 to SQR4 in the SQRR register if the complete M bit multiframe pattern was
corre ctly received in the corr esponding m ultiframe. A change in any of the rece ived four bits
(SQR1, 2, 3 or 4) is indicated by an interrupt (CISQ in ISTA and SQC in CIR0).
– Whe n an M b it is obser ved to ha ve a valu e dif feren t from tha t expecte d, the synch roni sm is
considered lost. The SQR bits are not updated until synchronism is regained. The
synchroniza tion state is constantly indica ted by t he SYN b i t in the SQRR register.
– When synchronism with the received multiframe is achieved, the four bits SQX1 to SQX4
stored in the SQXR register are transmitted as the four Q bits (FA-bit position) in frames 1,
6, 11 and 16 respectively (starting from frame number one). Otherwise the bit transmitted is
a mirror of the received FA-bit. At loss of synchronism (mismatch in M bit) the mirroring is
resumed s tarting with the next FA-bit.
– The S/T multiframe synchronization can be disabled in the STAR2 register (MULT bit).
Command (upstream)
Activate request, set priority 8
Remarks
Activation command: Set D-channel
priority to 8
Abbr.
AR8
Code
1000
Activate request, set priority 10 Activation command: Set D-channel
priority to 10
AR10 1001
Indication (downstream)
Activate indication with priority
class 8
Remarks
Info 4 received: D-channel priority is 8
or 9
Abbr.
AI8
Code
1100
Activate indication with priority
class 10 Info 4 received: D-channel priority is
10 or 11
AI10 1101
Semicond uctor Group 59
Functional Description
Table 5
S- and Q-Bit Position Identification and Multiframe Structure
S- and Q-Channel Structure
Frame Number
1
2
3
4
5
NT-to-TE
FA-Bit
Position
ONE
ZERO
ZERO
ZERO
ZERO
NT-to-TE
M Bit
ONE
ZERO
ZERO
ZERO
ZERO
NT-to-TE
S Bit
S1
ZERO
ZERO
ZERO
ZERO
TE-to-NT
FA-Bit
Position
Q1
ZERO
ZERO
ZERO
ZERO
6
7
8
9
10
ONE
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
S2
ZERO
ZERO
ZERO
ZERO
Q2
ZERO
ZERO
ZERO
ZERO
11
12
13
14
15
ONE
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
S3
ZERO
ZERO
ZERO
ZERO
Q3
ZERO
ZERO
ZERO
ZERO
16
17
18
19
20
ONE
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
ZERO
S4
ZERO
ZERO
ZERO
ZERO
Q4
ZERO
ZERO
ZERO
ZERO
1
2
etc.
ONE
ZERO ONE
ZERO S1
ZERO Q1
ZERO
Semicond uctor Group 60
Functional Description
2.5 Terminal Specific Functions
Watchdog and External Awake
In addition to the ISAC-S TE standard functions supporting the ISDN-basic access, the
ISAC-S TE contains optional fu nctions, use ful in v arious terminal configurations .
The terminal specific functions are enabled by setting bit TSF (STCR register) to "1". This has
two effects:
The EAW line is defined as an external awake input;
Second, the interrupts SAW and WOV (EXIR register) are enabled:
●SAW (Subscriber Awake) generated by a fallin g edge on the EAW line
●WOV (Watchdog timer OVerflow) generated by the watchdog timer. This occurs when the
processor fails to write two consecutive bit patterns in ADF1:
The WTC1 and WTC2 bits have to be successively written in the following manner within
128 ms:
As a result the watchdog timer is reset and restarted. Otherwise a WOV is generated.
Deactivating the terminal specific functions is only possible with a hardware reset.
Having enabled the terminal specific functions via TSF=1, the user can make the ISAC-S TE
generate a reset signal by programming the Reset Source Select RSS bit (CIXR/CIX0
register), as follows:
0 →A reset signal is generated as a result of
– a falling ed ge on th e EAW lin e (subscriber awake)
– a C/I code change (exchange awake)
A falling edge on the EAW line also forces the IDP1 line of the IOM interface to zero.
The consequence of this is that the IOM interface and the ISAC-S TE leaves the
power-down state.
A corresponding interrupt status (CISQ or SAW) is also generated.
1 →A reset signal is generated as a result of the expiration of the watchdog timer
(indicated by the WOV interrupt status).
Note that the watchdog timer is not running when the ISAC-S TE is in the power-down
state (IOM not clocked).
Note: Bit RSS has a significance only if terminal specific functions are activated (TSF=1).
ADF1 WTC2WTC1
Watchdog Timer Control 1, 0.
WTC1 WTC2
1
0
1.
2. 0
1
Semicond uctor Group 61
Functional Description
The RS S bit should be set to "1 " by the us er when the ISAC-S TE i s in powe r-up to p revent an
edge on the EAW line or a change in the C/I code from generating a reset pulse.
Switching RSS from 0 to 1 or from 1 to 0 resets the watchdog timer.
The reset pulse generated by the ISAC-S TE (output via RST pin) has a pulse width of:
–125µs when generated by the watchdog timer
– 16 ms when generated by EAW line or C/I-code change.
Semicond uctor Group 62
Functional Description
2.6 Test Functions
The ISAC-S TE provides several test and diagnostic functions which can be grouped as
follows:
●digital loop via TLP (Test Loop, SPCR register) command bit: IDP1 is internally connected
with IDP0, output from layer 1 (S/T) on IDP0 is ignored; this is used for testing ISAC-S TE
function ality excluding layer 1;
● test of layer-2 functions while disabling all layer-1 functions and pins associated with them
(including clocking, in TE mode), via bit TEM (Test Mode in ADF1 register); the ISAC-S TE
is then fully compatible to the ICC (PEB 2070) seen at the IOM interface.
●loop at the analog end of the S interface;
Test loop 3 is activated with the C/I-channel command Activate Request Loop (ARL). An S
interface is not required since INFO3 is looped back to the receiver. When the receiver has
synchronized itself to this signal, the messag e "Test Indi cation" (or "Awake Test Indication") is
delivered in the C/I channel. No signal is transmitted over the S interface.
In the test loop mode the S-Interface awake detector is enabled i.e. if a level is detected (e.g.
Info 2/Info 4) this will be repo rted by the Awake Test Indica tion (ATI). The loop function is not
effected by this condition and the internally generated 192-kHz line clock does not depend on
the signal received at the S interface.
Semicond uctor Group 63
Functional Description
2.7 Layer-2 Functions for the ISDN-Basic Access
LAPD, layer 2 of the D-channel protocol (CCITT I.441) includes functions for:
– Provision of one or more data link connections on a D channel (multiple LAP).
Discrimination between the data link connections is performed by means of a data link
connection identifier (DLCI = SAPI + TEI)
– HDLC frami ng
– Application of a balanced class of procedure in point-multipoint configuration.
The simplifi ed block diagra m in figure 30 shows the functional b locks of the ISAC-S TE which
support the LAPD protocol.
Figure 30
D-Channel Processing of the ISAC®-S TE
For the support of LAPD the ISAC-S TE contains an HDLC transceiver which is responsible
for flag generation/recognition, bit stuffing mechanism, CRC check and address reco gnition.
A powerful FIFO structure with two 64-byte pools for transmit and receive directions and an
intelligent FIFO controller permit flexible transfer of protocol data units to and from the µC
system.
ITS00861
Status
Command
Registers
Controller
LAPDHDLC
TransmitterReceiver
HDLC
R-FIFO X-FIFO FIFO
Controller
2 x 32 byte
P-Interface
µ
µC-System
Layer-1
Functions
S(D-Channel)
Layer 1
2Layer
Layers
Upper
R
IOM
2 x 32 byte
Semicond uctor Group 64
Functional Description
2.7.1 Message Transfer Modes
The HDLC controller can be programmed to operate in various modes, which are different in
the treatment of the HDLC frame in the receive direction. Thus, the receive data flow and the
address recognition features can be programmed in a flexible way, which satisfies different
system require ments.
In the auto mode the ISAC-S TE handles elements of procedure of the LAPD (S and I frames)
according to CCITT I.441 fully autonomously.
For the address recognition the ISAC-S TE contains four programmable registers for individual
SAPI and TEI values SAP1-2 and TEI1-2, plus two fixed values for "group" SAPI and TEI,
SAPG and TEIG.
There are 5 different operating modes which can be set via the MODE register (addr. 22H):
Auto-mode (MDS2, MDS1 = 00)
Characteristics:
– Full address recognition (1 or 2 bytes).
– Normal (mod 8) or extended (mod 128) control field format
– Automatic proces sing of number ed frames of a n HDLC proc edure (see 2.7.5)
If a 2-byte address field is selected, the high address byte is compared with the fixed value
FEH or FCH (group address) as well as with two individually programmable values in SAP1
and SAP2 regi sters. Accordi ng to the ISDN LA PD pr oto col, bit 1 o f the h igh byte add ress will
be interpreted as command/response bit (C/R) dependent on the setting of the CRI bit in
SAP1, and will be excluded from the addre ss comparison.
Similarly, the low address byte is compared with the fixed value FFH (group TEI) and two
compare values programmed in special registers (TEI1, TEI2). A valid address will be
recognized in case the high and low byte of the address field match one of the compare values.
The ISAC-S TE can be called (addressed) with the following address combinations:
– SAP1/TEI1
– SAP1/FFH
– SAP2/TEI2
– SAP2/FFH
–FE
H
(FCH)/TEI1
–FE
H
(FCH)/TEI2
–FE
H
(FCH)/FFH
Only the logical connection identified through the address combination SAP1, TEI1 will be
processed in the auto mode, all others are handled as in the non-auto mode. The logical
connection handled in the auto-mode must have a window size 1 between transmitted and
acknowledged frames. HDLC frames with address fields that do not match with any of the
address combinations, are ignored by the ISAC-S TE.
Semicond uctor Group 65
Functional Description
In case of a 1-byte address, TEI1 and TEI2 will be used as compare registers. According to
the X.25 LAPB protocol, the value in TEI1 will be interpreted as command and the value in
TEI2 as response.
The control field is stored in the RHCR register and the I field in the RFIFO. Additional
informatio n is available in the RSTA.
Non-auto mode (MDS2, MDS1 = 01 )
Characteristics:Full address recognition (1 or 2 bytes)
Arbitrary window sizes
All frames with valid addresses (address recognition identical to auto mode) are accepted and
the bytes following the address are transferred to the µP via RHCR and RFIFO. Additional
informatio n is available in the RSTA.
Transparent mode 1 (M DS2, MDS1, MDS0 = 101)
Characteristics: TEI recognition
A comparison is performed only on the second byte after the opening flag , with TEI1, TEI2 and
group TEI (FFH). In the case of a match, the first address byte is stored in SAPR, the (first byte
of the) control field in RHCR, and the rest of the frame in the RFIFO. Additional information is
available in the RSTA.
Transparent mode 2 (M DS2, MDS1, MDS0 = 110)
Charac te risti cs: no add r ess rec ogn it ion
Every received frame is stored in the RFIFO (first byte after opening flag to CRC field).
Additional information can be read from the RSTA.
Transparent mode 3 (M DS2, MDS1, MDS0 = 111)
Characteristics: SAPI recognition
A compar ison is per formed on th e first byte after the ope ning flag wi th SAP1, SAP 2 and gro up
SAPI (FE/FC H). In the case of a match, all the following bytes are stored in RFIFO. Additional
information can be read from th e RSTA.
Semicond uctor Group 66
Functional Description
2.7.2 Protocol Operations (auto-mode)
In addition to address recognition all S and I frames are processed in hardware in the auto-
mode. The following functions are performed:
– update of transmit and receive counter
– evaluation of transmit and receive counter
– processing of S commands
– flow control with RR/RNR
– response generation
– recognition of protocol errors
– transmission of S commands, if an acknowledgement is not received
– continuous status query of remote station after RNR has been received
– programmable timer/repeater functions.
The processing of frames in auto-mode is described in detail in chapter 2.7.5:
Documentation of the Auto-Mode.
Semicond uctor Group 67
Functional Description
2.7.3 Reception of Frames
A 2×32 byte FIFO buffer (receive pools) is provided in the receive direction.
The contro l of the data tra nsfer between t he CPU and the IS AC-S TE is handl ed via interru pts.
There are two different interrupt indic ations concerned with th e reception o f data:
– RPF (Rec eive Pool Full) interru pt, in dicat ing t hat a 32 -byt e block of da ta can be read from
the RFIFO and the received message is not yet complete.
– RME (Receive Message End) interrupt, indicating that the reception of one message is
complete d, i .e. ei the r
●one message ≤32 bytes, or
●the last part of a message > 32 bytes
is stored in the RFIFO.
Depend ing on the message transfer mode the addr ess and control fields o f receiv ed frames
are processed and stored in the Receive FIFO or in special registers as depicted in figure 32.
The organ ization of the R FIFO is such that up to two sho rt (≤32 bytes), successive messag es,
with all additional inf ormation can be stored. The contents of the RFIFO would be, fo r example,
as shown in figure 31.
Figure 31
Contents of RFIFO (short message)
ITS01502
31
31
0
0
Receive
Message 2
bytes)32 1Message
Receive
RME
RME
Interrupts in
Wait Line
RFIFO
(
_
<
bytes)
_
<
(32
Semicond uctor Group 68
Functional Description
Figure 32
Receive Data Flow
Note 1 Only if a 2-byte address field is defined (MDS0 = 1 in MODE register).
Note 2 Comparison with Group TEI (FFH) is only made if a 2-byte address field is defined
(MDS0 = 1 in MODE register).
Note 3 In the case of an extend ed, modu lo 128 con trol field fo rmat (MC S = 1 in SAP2 r egister)
the control field is stored in the RHCR in compressed form (I frames).
Note 4 In the case of extended control field, only the first byte is stored in the RHCR, the se-
cond in the RFIFO.
ITD05674
Description of Symbols:
Checked automatically by ISAC
Compared with Register or Fixed Value
Stored Info Register or RFIFO
Flag High
Address Address
Low Control Information CRC Flag
RSTARHCR
FF
TEI1,TEI2SAP1,SAP2
FE,FC
(Note 1) 2)(Note (Note 3)
RFIFO
RFIFO
FE,FC
SAP1,SAP2 TEI1,TEI2
FF RHCR RSTA
4)(Note (Note 2)1)(Note
RSTA
FF
TEI1,TEI2 RFIFO
RSTA
SAPR
RSTA
RFIFO
RFIFO
SAP1,SAP2
FE,FC
Auto-Mode
(U-and Ι
Non-Auto
Mode
Mode
Transparent
1
2
Transparent
Mode
3
Transparent
Mode
--Frames)
(Note 4)
RHCR
-S TE
R
Semicond uctor Group 69
Functional Description
When 32 bytes of a message longer than that are stored in the RFIFO, the CPU is prompted
to read out the data by an RPF interrup t. The CPU must handle this interru pt before more than
32 additional bytes are received, which would cause a "data overflow".This corresponds to a
maximum CPU reaction time of 16 ms (data rate 1 6 kbit/s).
After a remaining block of less than or equal to 16 bytes has been stored, it is possible to store
the first 16 bytes of a new message (see figure 33).
The internal memory is now full. The arrival of additional bytes will result in "data overflow"
(RSTA:RDO) and a third new message in "frame overflow" (EXIR:RFO).
The ge nerated interrupts are ins erted to gether wit h all ad ditional informati on into a queu e to
be individually passed to the CPU.
After an RPF or RME interrupt has been processed, i.e. the received data has been read from
the RFIFO, this must be explicitly acknowledged by the CPU issuing an RMC (Receive
Message Complete) co mmand.
The ISAC-S TE can then release the associated FIFO pool for new data. If there is an
additional interrupt in the que ue it will be generated a fter the RMC acknowled gement.
Figure 33
Contents of the RFIFO (long messages)
ITS01501
31
31
0
0
Message 2
1Message
Long
RPF
RME
Interrupts in
the Queue
RFIFORFIFO
the Queue Interrupts in
RPF
RPF
Long
Message
0
0
31
31
15
16 RME
bytes)46
<
(
_
bytes)32
<
(
_
Semicond uctor Group 70
Functional Description
Information about the received frame is available for the µP when a RME interrupt is generated,
as shown in table 6.
Table 6
Receive Information at RME Interrupt
Information
Recognition of TEI
Mode
All except transparent modes 2, 3RSTA (27) TA
First byte af ter flag
(SAPI of LAPD
address fiel d)
Transparent mode 1SAPR (26) –
Control field Auto-mode, I (modulo 8) and U framesRHCR (29) –
Compressed control field Auto-mode, I frames (modulo 128)RHCR (29) –
Type of frame
(Command/Response) Auto-mo de, 2 byte address f ield
Non-auto mode, 2-byte address field
Transparent mode 3
RSTA (27) C/R
2nd byte after flag Non-auto mode, 1-byte address fieldRHCR (29) –
3rd byte after flag Non-auto mode, 2-byte address field
Transparent mode 1
RHCR (29) –
Recognition of SAPI Auto-mode, 2 byte addres s field
Non-auto mode, 2-byte address field
Transparent mode 3
RSTA (27) SA1-0
Result of CRC check
(correct/incorrect) ALLRSTA (27) CRC
Data available in RFIFO
(yes/no) ALLRSTA (27) RDA
Abort condition detected
(yes/no) ALLRSTA (27) RAB
Number of bytes received
in RFIFO ALLRBCL (25) RBC4-0
Message length ALLRBCL
RBCH (25)
(2A) RBC11-0
OV
Data overflow during
reception of a frame
(yes/no)
ALLRSTA (27) RDO
Register (adr.
hex) Bit
Semicond uctor Group 71
Functional Description
2.7.4 Transmi ssi on of Frames
A 2×32 byte FIFO buffer (transmit pools) is provided in the transmit direction.
If the transmit pool is ready (which is true after an XPR interrupt or if the XFW bit in STAR is
set), the CPU can write a data block of up to 32 bytes to the transmit FIFO. After this, data
transmission can be initiated by command.
Two different frames types can be transmitted:
– Transparent frame (command: XTF), or
– I frames (command: XIF)
as shown in figure 34.
For tra nsparen t fra mes, t he w hole fr ame includ ing ad dress and co ntro l fi eld m ust be writt en to
the XFIFO.
Figure 34
Transmitter Data Flow
The transmission of I frames is possible only if the ISAC-S TE is operating in the auto-mode.
The address and control field is autonomously generated by the ISAC-S TE and appended to
the frame, only the data in the information field must be written to the XFIFO.
ITD05667
Flag Address Control Information CRC Flag
FlagCRCXFIFOControlXAD1Flag
HDLC Frame
Flag XAD1 Control XFIFO CRC Flag
FlagCRCXFIFOFlag
XAD2
(XIF)
Transmit I-Frame
Auto Mode,8
16Auto Mode,
Transmit I-Frame
(XIF)
All Modes
Transmit Transparent
Frame (XTF)
Note: Length of Control Field is b or 16
Description of Symbols:
Bit
Bit Addr.
Bit Addr.
Generated automatically by ISAC
Written initially by CPU
Loaded (repeatedly)
(Info Register)
by CPU upon ISAC
(XPR Interrupt)request
-
-
-
R
-S TE
-S TE
R
Semicond uctor Group 72
Functional Description
If a 2-byte address field has been selected, the ISAC-S TE takes the contents of the XAD 1
register to build the high byte of the address field, and the contents of the XAD 2 register to
build the low byte of the address field.
Additionally the C/R bit (bit 1 of the high byte address, as defined by LAPD protocol) is set to
"1" or "0" dependent on whether the frame is a command or a response.
In the case of a 1 byte address, the ISAC-S TE takes either the XAD 1 or XAD 2 register to
differentiate between command or response frame (as defined by X.25 LAPB).
The contr ol field is also genera ted by th e ISAC- S TE inclu ding the r eceive and send seq uence
number and the poll/final (P/F) bit. For this purpose, the ISAC-S TE internally manages send
and receive sequence number counters.
In the auto-mode, S frames are sent autonomously by the ISAC-S TE. The transmission of U
frames, however, must be done by the CPU. U frames must be sent as transparent frames
(CMDR:XTF), i.e. address and con trol field must be defined by the CPU.
Once the data transmission has been initiated by command (CMDR:XTF or XIF), the data
transfer between CPU and the ISAC-S TE is controlled by interrupts.
The IS AC-S TE re pea tedly reques ts a nothe r data pack et or bl ock b y mea ns of an IST A:XPR
interrupt, every time no more than 32 bytes are stored in the XFIFO.
The processor can then write further data to the XFIFO and enable the continuation of frame
transmission by issuing an XIF/XTF command.
If the data block which has been written last to the XFIFO completes the current frame, this
must be indicated additionally by setting the XME (Transmit Message End) command bit. The
ISAC-S TE then terminates the frame p roperly by appending the CRC and closing flag.
If the CP U fai ls to re spond to an XP R i n ter r up t w i thi n t he g i ven reaction ti m e, a da ta underr un
condition occurs (XFIFO holds no further valid data). In this case, the ISAC-S TE automatically
aborts the current frame by sending seven consecutive "ones" (ABORT sequence).
The CPU is informed about this via an XDU (Transm it Data Und errun) interrupt.
It is also possible to abort a message by software by issuing a CMDR:XRES (Transmitter
RESet) command, which causes an XPR interrupt.
After an end of message indication from the CPU (CMDR:XME command), the termination of
the transmission operation is indicated differently, depending on the selected message
transfer mode and the transmitted frame type.
If the ISAC-S TE is operating in the auto mode, the window size (= number of outstanding
unacknowledged frames) is limited to "1"; therefore an acknowledgement is expected for every
I frame sent with an XIF command. The acknowledgement may be provided either by a
received S or I frame with corresponding receive sequence number.
If no acknowledgement is received within a certain time (programmable), the ISAC-S TE
requests an acknowledgement by sending an S frame with the poll bit set (P = 1) (RR or RNR).
If no response is received again, this process is repeated in total N2 times (retry count,
programmable via TIMR register).
Semicond uctor Group 73
Functional Description
The terminat ion of the transmission op eration may be indicated either with:
– XPR interrupt, if a positive acknowledgement has been received,
– XMR interrupt, if a negative acknowledgement has been received, i.e. the transmitted
message must be repeated (XMR = Transmit Message Repeat),
– TIN interrupt, if no acknowledgement has been received at all after N2 times the expiration
of the time period t1 (TIN = Timer INterrupt, XPR interrupt is issued additionally).
Note: Prerequi site for sendin g I frames in the auto -mode (XIF) is that the internal operational
mode of the timer has be en selected in th e MODE register (TMD bi t = 1).
The transparent transmission of frames (XTF command) is possible in all message transfer
modes. The successful termination of a transparent transmission is indicated by an XPR
interrupt.
In all cases, collisions which occur on the S-Bus (D channel) before the first XFIFO pool has
been c omp let ely tr ans mitt e d a nd rel ea sed ar e t re ate d wi th out µP in teraction. The ISAC-S TE
will retransmit the frame automatically.
If a collision is detected after the first pool has been released, th e ISAC-S TE aborts the frame
and requests the processor to repeat the frame with an XMR interrupt.
Semicond uctor Group 74
Functional Description
2.7.5 Documenta tion of the Auto Mode
The auto mode of the ICC and ISAC-S TE is only applicable for the states 7 and 8 of the LAPD
protocol. All other states (1 to 6) have to be performed in Non-Auto Mode (NAM). Therefore
this documentation gives an overview of how the device reacts in the states 7 and 8, which
reactions require software programming and which are done by the hardware itself, when
interrupts and status register contents are set or change. The necessary software actions are
also detailed in terms of command or mode register access.
The description is based on the SDL diagrams of the ETSI TS 46-20 dated 1989.
The diag rams are only a nnota ted by docu ment ary signs o r texts (mo stly re gister de scripti ons)
and ca n there fore ea sily be inte rprete d by any one fa miliar wit h the S DL desc ripti on of LA PD.
All deviations that occur are specially marked and the impossible actions, paths etc. are
crossed out.
To get acquainted with this documentation, first read through the legend-description and the
additional general considerations, then start with the diagrams, referring to the legend and the
register description in the Technical Manual if necessary.
We hope you will profi t fro m this documenta tion and us e our software-saving auto-mode.
2.7.5.1 Legend of the Auto-Mode Documentation
a.Symbols within a path
There are 3 symbols within a path
a.1.
a.2.
a.3.
In the auto-mode the device processes all subsequent stat
e
transitions branchings etc. up to the next symbol.
In the auto-mode the device does not process the state transitions,
branchings etc. Within the path appropriate directions are given wit
h
which the software can ac complish the required action.
A
pa
th
canno
t
b
e
i
mp
l
emen
t
e
d
an
d
no so
ft
ware or
h
ar
d
ware ac
ti
o
n
can chan ge this. These p aths are ei ther opti onal or only app licable fo
r
window-size > 1.
Semicond uctor Group 75
Functional Description
b.Symbo ls at a path
There is 1 symbol at a path
b.1.
c.Symbols at an internal or exte rnal messa ge box .
There are 2 symbols at a message box.
c.1.
Note: The impossibility to perform the optional T203 timer-procedure is not explicitly
mentioned; the corresponding actions are only crossed out.
c.2.
d.Text within boxes
Text within boxes can be gr ouped in one of two clas ses.
d.1.
d.2.The text describes a register access
The text is placed in the box that describes the functions for which the register access is
needed.
marks the beginning of a path, for which a.3 applies.
This symbol means, that the action described in the box is not
possible. Either the action specified is not done at all or an additional
action is taken (written into the box).
Box
This symbol means, that within a software-path, by taking the
prescribed register actions the contents of the box will be done
automatically.
Box
The text denotes an interrupt which is always associated with the
event . (But can also be asso ciated with oth er events). (See ISTA- and
EXIR-register description in the Technical Manual for an interrupt
description).
Text
Text
Box
Box or
either a register read access to discriminate this state from others or
to reach a branching condition
or a register write access to give a command.
Text
Box
Semicond uctor Group 76
Functional Description
e.Text attac hed at the side of boxes
e.1.
e.2.
(The attached texts can also be placed on the left side.)
f.Text above and below boxes
f.1.
f.2.
g.Shade boxes
The text describes an interrupt associated with the contents of the
box. The interrupt is always associated with the box contents, if the
interrupt name is not followed by a "/", it is associated only under
appropriate conditions if a "/" is behind it.
Text
Box
The text describes a possible or mandatory change of a bit in a status-
register associated with the contents of t he box.
Text
Box
Text descri bes a m andatory a ction to be perfo rmed on t he conten ts of
the box.
Text
Box
Text describes a mandatory action to be taken as a result of the
contents of the box.
Action here means register access.
Text
Box
The box describes an impossible state or action for the device.
Box
Semicond uctor Group 77
Functional Description
2.7.5.2 Additional General Considerations when Using the Auto Mode
a)Switching from auto-mode to non-auto mode.
As mentioned in the introduction the auto mode is only applicable in the states 7 and 8 of the
LAPD. Therefore whenever these states have to be left (which is indicated by a "Mode:NAM"
text) there are several actions to be taken that could not all be detailed in the SDL diagrams:
a.1)write non-auto mode and TMD = 0 into the mode register.
a.2)w rite t he ti m er registe r wi th an arbitrar y val ue t o stop i t . Th e timer T2 00 a s sp ecif ied in the
LAPD protocol is implemented in the hardware only in the states 7 and 8; in all other states this
or any other ti mer- procedu re h as to b e don e by t he softwa re wi th th e possibl e use of th e ti mer
in external timer mode.
a.3)r ead the WF A bit of the STAR2 re gister and store it i n a softwar e variable . The info rmation
in this bit may be necessary for later decisions. When switching from auto mode to non-auto
mode XPR interrupts may be lost.
a.4)In the non-auto mode the software has to decode I-, U- and S frames because I and S
frames are only handled autonomously in the auto-mode.
a.5)The RSC and PCE interrupts, the contents of the STAR2 register and the RRNR bit in the
STAR register are only meaningful within the auto-mode.
a.6)leave some time before RHR or XRES is written to reset the counters, as a currently sent
frame may not be finished yet.
b)What has to be written to the XFIFO?
In the l egend description when th e software has to wr ite cont ents of a frame to t he XFIFO on ly
"XFIFO" is shown in the corresponding box. We shall give here a general rule of what has to
be written to the XFIFO:
a) For send ing an I frame with CMDR:XIF, o nly the information fie ld content, i.e . no SAPI, TEI,
Control field should be written to the XFIFO.
b) For sending a U frame or any other frame with CMDR:XTF, the SAPI, TEI and the control
field has to be written to the XFIFO.
c)The inter rupts XPR and XMR.
The occurence of an XPR interrupt in auto-mode after an XIF command indicates that the
I frame sent was acknowledged and the next I frame can be sent, if STAR2:TREC indicates
state 7 and STAR:RRNR indicates Peer Rec not busy. If Peer Rec is busy after an XPR, the
software should wait for the next RSC interrupt before sending the next I frame. If the XPR
happen s to be in the time r recovery stat e, the softwa re has to poll the STAR2 registe r until the
state multiple frame established is reached or a TIN interrupt is issued which requires auto
mode to be left (One of these two co nditions will occur before the time T200×N200). In non-
auto mode or after an XTF command the XPR just indicates, that the frame was sent
successfully.
Semicond uctor Group 78
Functional Description
The occurence of an XMR interrupt in auto-mode after an XIF command indicates that the
I frame sent was either rejected by the Peer Entity or that a collision occured on the S interface.
In both cases the I frame has to be retransmitted (after an eventual waiting for the RSC
interrupt if the Peer Rec was busy; after an XMR the device will always be in the state 7). In
non-auto mode or after an XTF command the XMR indicates that a collision occured on the
S interface and the frame has to be retransmitted.
d)The resetting of the RC variable:
The RC variab le is reset in th e ICC and ISAC-S TE when l eaving the state ti mer recovery. The
SDL diagrams indicate a reset in the state multiple frame established when T200 expires.
There is no difference to the outside world between these implementations however our
implem en tation is clear er .
e)The timer T203 procedure:
We do not fully support the optional time r T203 proc edure, but we can still find out whether or
not S frames are sent on the link in the auto-mode. By polling the STAR2:SDET bit and
(re)starting a software timer whenever a one is read we can build a quasi T203 procedure
which h andles ap proximatel y the same task. Wh en T203 exp ires one i s supposed to go into
the tim er recovery state with RC = 0. This is possible for the ICC and ISAC-S TE by just wri ting
the STI bit in the CMDR register (auto-mode and internal timer mode assumed).
f)The congestion procedure as defined in the 1 TR 6 of the "Deutsche Bundespost":
In the 1 TR 6 a variable N 2 ×4 is defined for the maximum number of Peer Busy requests. The
1 TR 6 is in this respect not compatible with the Q921 of CCITT or the ETSI 46-20 but it is,
nevertheless, sensible to avoid getting into a hangup situation. With the ICC and ISAC-S TE
this procedure can be implemented:
After receiving an RSC interrupt with RRNR set one starts a software-timer. The timer is reset
and st opped if on e ei ther re ceives a no ther RSC inte rrup t wit h a r eset RR NR, if on e rece ives a
TIN interrupt or if other conditions occur that result in a reestablishment of the link. The timer
expires af te r N2 ×4×T200 and in this case the 1 TR 6 recommends a reestablishment of the
link.
2.7.5.3 Dealing With Error Conditions in Auto Mode
In the Recommendation Q.921 of CCITT (Blue Book) several error conditions are described.
We shall de al with them as far as the y touch t he auto mod e of the ISA C-S (whi ch only appl ies
for states 7,8 of Q.921).
Through out the followi ng document in subsections 1 w e shall give the or iginal Q.921- Text. For
better discrimination against comments the original text is printed in italic characters. Please
note that Q.921/table 5 has been corrected according to Corrigendum No. 1 10/1989.
Subsections 2 d ocument how the ISAC-S rea ct in all cases, and su bsec tions 3 will give hin ts
how your software should respond to these reactions.
Invalid Frames and Frame Abortion
During data tr an smi ssi on i nva l id fr a me s a nd frame abo r ti on generally le ad to err or co nd itions.
Semicond uctor Group 79
Functional Description
Q921: Invalid Frames and Frame Abortion
Paragraphs 2.9 and 2.10 of the Q.921 deal with Invalid Frames and Frame Abortion. In the
following the original text is given.
Q.921 § 2.9: Invalid Frames
An inv alid frame is a frame which:
a) is not properly bounded by two flags, or
b) has fewer than 6 octets between flags or frames that contain sequence numbers, or
c) does no t consist of an integral number of octe ts prior to ze ro bit inser tion or foll owing zero
bit extraction, or
d) c ontain s a frame check sequence error, or
e) contains a single octet address field, or
f) contains a service access point identifier (see § 3.3.3) which is not supported by the
receiver.
Invalid frames shall be discarded without notification to the sender. No action is taken as the
result of that frame.
Q.921 § 2.10: Frame Abort
Receipt of seven or more contiguous 1 bits shall be interpreted as an abort and the data link
layer shall ignore the frame currently being received.
Reaction of the ISAC-S TE
a) A frame which does not start with a flag is discarded in the ISAC-S TE. A frame which
does not end with a flag is one, that is aborted, i.e. if § 2.9b does not apply then the
ISAC-S TE
– dis cards t he frame, if i t was an S-frame
or, if it was an I or U-frame
– generates an ISTA: RME (or RPFs and a RME) and
– puts RSTA: RAB = 1 after the RME-Interrupt RAB = 1.
A frame is supposed to be unbounded according to § 5.8.5 if the byte counter RBCH, RBCL
after RPF or RME exceeds 528.
b) The frame is discarded by the ISAC-S TE if
with U-frames or undefined framesit contains less or equ al to 4 octets or
with I-framesit contains less or equal to 5 octets
with S-frames it contains less than 6 octets.
For U- frame s wit h a conten t betwe en 4 an d 5 o ctets e xclus ively o r fo r I- frames betw een 5 and
6 octets exclusively an ISTA: RME interrupt is generated and afterwards the RSTA: CRC is set
to 0.
c) An S- frame is discarded. In the own-rec eiver -busy state I-frames are discarded.
For an I-frame in the normal state and U frames, after several possible RPF interrupts and
the final RME interrupt, the bit RSTA: CRC is set to 0 in this case.
d) In c ase of an -S frame, the frame is discarded
-U and I-framesRSTA: CRC is set to "0" in this case.
e) the frame is discarded
f) the frame is discarded
Semicond uctor Group 80
Functional Description
The reaction to § 2.10 has been already discussed under a)
Necessary Software Actions
The software sho uld read the Register RSTA after a RME-interrupt. After having read RAB = 1
or CRC = 0, all fram e contents read from the FIFO sho uld be dis carded and a CMDR: RMC
should be written. After each RPF or RBCH, RBCL should be read and if it exceeds 528,
CMDR: RRES should be written. In this way all invalid frames are discarded by the software.
Data Overflow
In case of a d ata overflow , which is only possible while r eceiving a n I-frame or an U- frame with
a non-empty information field, the ISAC-S TE interrupt with ISTA: RME and sets RSTA: RDO
to 1. A RSTA: RDO and an ISTA: RFO are a hint that the dynamic reaction time of your
software to the RPF, RME interrupt is too slow, so you should change your software. During
the development phase you may set CMDR: RNR after an RDO, RFO-condition to protect
again st furthe r errors, but the fi nal solution can only be to exclude RDO, RFO condi tions by an
improved software design.
Frame Rejection Condition
Q.921 § 5.8.5: Frame Rejection Condition
A frame rejectio n condit ion results from one of the followi ng conditions:
a) the receipt of an undefined frame (see § 3.6.1, third paragraph)
b) the receipt of a supervisory or unnumbered frame with incorrect length
c) the receipt of an invalid N(R), or
d) the receipt of a frame with an information field which exceeds the maximum established
length.
Upon occurr ence of a frame reje ction conditi on whilst in the mu ltiple fram e operatio n, the data
link layer entity shall:
– issue a MDL-ERROR -INDICATION primitive, and
– initiate re-establishment (see § 5.7.2).
Upon occurrence of a frame rejection condition during establishment of or release from
multiple frame operation, or whilst a data link is not established, the data link layer entity shall:
– issue a MDL-ERROR -INDICATION primitive, and
– discard the fram e.
Note: For satisfactory operation it is essential that a receiver is able to discriminate between
invalid fr am e s, as defi n ed in § 2. 9, an d fram es w it h an infor mat ion fie ld which exceeds
the ma ximum establi shed length (see § 3.6.11 item d). An unbounded frame may be
assumed, and thus discarded, if two times the longest permissible frame plus two octets
are received without a flag detection
.
Semicond uctor Group 81
Functional Description
For a better understanding we insert the text of § 3.6.1, which is referred to in § 5.8.5 and which
reads:
§ 3.6.1 Commands and responses
The following commands and responses are used by either the user or the network data link
layer entities and are represented in Q.921/table 5. Each data link connection shall support
the full set of commands and responses for each application implemented. The frame types
associated with each of the two applications are identified in Q.921/table 5.
Frame types a ssociated wit h an appl icati on n ot imp lemen ted sh all b e di scarded and no a ction
shall be taken as a result of that frame.
For purposes of the LAPD procedures in each application, those frame types not identified in
Q.921/table 5 are ident ified a s undefi ned comma nd and/o r response control fi eld. The a ctions
to be taken are specified in § 5.8.5.
We include the original table 5 which is mentio ne d in § 3.6.1:
Semicond uctor Group 82
Functional Description
Table 7
Q.921 (Table 5)
*Note: Use of the XID fra me oth er than fo r param eter nego tiation procedu res (see § 5.4 ) is fo r
further study. The co mmands a nd respo nses in Q. 921 /table 5 a re de fine d in § 3.6.2 to
§ 3.6.12
Application Format Command
sResponses Encoding Oct
et
87654321
Unacknowledged
and Multiple-
Frame
acknowledged
Information
Transfer
Informati on
Transfer I(nformation) N(S) 0 4
N(R) P 5
Supervisory
RR
(receive rea-
dy)
RR
(receive ready) 00000001 4
N(R) P/F 5
RNR
(receive not
ready)
RNR
(recei ve not rea-
dy)
00000101 4
N(R) P/F 5
REJ
(reject) REJ
(reject) 00001001 4
N(R) P/F 5
Unnumbe-
red
SABM E
(set async.
balanced
Mode extd).
011P1111 4
DM
(disconnected
mode)
000F1111 4
UI
(Unnumbe-
red Informati-
on)
000P0011 4
DISC
(disconnect) 010P0011 4
UA
(unnumbered
Acknowledge-
ment)
011F0011 4
FRMR
(frame reject) 100F0111 4
Connection
Management XID*
(Exch. Ident) XID*
(Exch. Iden t) 101P
/
F
1111 4
Semicond uctor Group 83
Functional Description
Reaction of the ISAC-S TE
In the following various possibl e actions to be taken according to § 5.8.5 parts a) through c)
are discussed separately.
a) There are different types of undefined frames:
1) I-frame which is not a command an ISTA: PCE-interrupt is generated
2) S-frame with bits 8-5 in Octet 4 = 0 an ISTA: PCE-interrupt is generated
3) A frame with bits 4-1 in octet 4
equal to "1101" (selective reject) an ISTA: PCE is generated
4) Frame with bi ts 2-1 in octet 4 equal
to "11" but control field not contained
in ISTA : RME interrupt; the c ontrol field can be read afterwards in
RHCR (after having checked fo r invalid
frame condition).
5) SABME, UI, DISC, not a command,
DM, UA, FRMR not a response
ISTA: RME interru pt; the control fi eld can be read afterwards in
RHCR, the C/R-bit in the SAPR-register
(after having checked for invalid frame
condition).
b) If the length of the frame is too small 1.1.1b) applies and the frame is invalid. Therefore
incorrect length can only mean:
1) S-frame with more than 6 octets an ISTA:PCE-interrupt is generated; the
cont ents of the ad ditional octets is dis carded.
2) Undefined fram es with 5 oc tets,
bits 2-1 i n octet 4 not being equal
to "11" (e.g. modulo 8 S-frame) an ISTA:PCE-interrupt is generated
3) SABME, BM, DISC, UA-frame
with more than 5 octets after ISTA:
RME and identifying the frame by RHCR the
RSTA:RDA bit is 1 if the frames had more
than 5 octets and 0 if they had exactly 5 octets.
4) A FRMR with not exactly 10 octetsAfter a RME and identifying FRMR by
reading RHCR-register, the software h as to
read RBCH, RBCL. If OV = 1 or
RBC11-RBC0 = 0 … 101 then the FRMR did
not have exactly 10 octets.
c) An invalid N(R) is on e tha t does not meet the condition
V(A) < N(R) < V(S)
This cond itio n is a utom atically checke d within the de vice a nd in the case of an invali d N(R ) an
ISTA:PCE-interrupt is generated. An S-field response is done by the ISAC-S TE in all
prescribed cases of invalid N(R) automatically.
Semicond uctor Group 84
Functional Description
The processor should read RBCH, RBCL after each RPF, RME interrupt. If after an RPF or
RME the byte count exceeds 528 then CMDR:RRES should be written (abort of frame). The
frame was invalid in this case but it was not a frame rejection condition. If after a RME the byte
count was between 260 and 528 inclusively and no other invalidity condition according to
section 1 applies or a data overflow according to section 2 occurred then a frame rejection
condition is detected.
Necessary Software Reactions
The softwa re can find out all fr ame rejection condit ions either by receiving PCE or by checking
RSTA, SAPR, RHCR, RBCH, RBCL after a RME interrupt, and RBCH, RBCL after an RPF
interru pt. In case of U-fram es i t has to be checked be for e, w he the r or n ot i t i s an i nva li d fram e
and has only to be discarded or, whether it was valid but leads to a frame rejection condition.
(Only valid frames can lead to frame rejection conditions according to § 5.8.4 of Q.921).
In case of a frame rejection condition the software has to take the actions defined in § 5.7.2
and issue a MDL-ERROR-INDICATION.
The particular action in § 5.7.2 reads:
§ 5.7.2 Proce dur e s
In all re-establishment situa tions, the data link layer entity shall follow the procedures defined
in § 5.5.1. All locally generated conditions for re-establishment will cause the transmission of
the SABME.
In case of data link layer and peer initiated re-establishments, the data link layer entity shall
also
– Issue a MDL-ERROR-INDICATION primitive to the connection management entit y: and
– rf V(S) > V(A) prior to re-establishment issue a DL-ESTABLISH-INDICATION primitive
to layer 3 and dis card all l-queues .
In case of layer-3 initiated re-establishment, or if a DL-ESTABLISH-REQUEST primitive
occurs pending re-establishment, the DL-ESTABLISH-CONFIRM primitive shall be used.
A frame rejection condition is not a pee r initiated re-establishment.
§ 5.5.1 is pretty voluminous. Here just the necessary actions to be done with the ISAC-S TE
shall be given, in case the re-establishment is successful at once:
– the softwa re should set the ISAC-S TE in to non-auto mode by writi ng the Mode regi ster
MODE: 6xH. Further ac tions that re sult from switch ing to non-au to mode shou ld also be
taken according.
– it should write FIFO : 76H, 6FH, CMDR : XTF to se nd a SABME-command with p = 1.
– upon having received a correct UA-frame it should
– write CMDR : XRES, RRES to set V(S) = V(A) = V(R) = 0
– write MODE: 3xH to re-enter auto mode for the mu ltiple-frame est ablished state.
If the re-est ablishment is not successful at on ce, in the non-auto mode further software actions
according to § 5.5.1 have to be taken.
Semicond uctor Group 85
Functional Description
Further Criteria Leadi n g to a Re-E stablishment
Q.921 § 5.7.1: Criteria for Re-Establishment
§ 5.7.1 Criteria for re-establishment
The criteria for re-establishing the multiple frame mode of operation are defined in this section
by the following conditions:
a) The receipt while in the multiple frame mode of operation, of an SABME;
b) The receipt of a DL-ESTABLISH-REQUEST primitive from layer 3 (see § 5.5.1.1 );
c) The occurrence of N200 re-transmission failures while in the timer recovery condition
(see § 5.6. 7)
d) The occurrence of a frame rejection condition as identified in § 5.8.5;
e) On the re ceipt, while in the multiple frame mode of op eration of an FRMR response frame
(see § 5.8.6);
f) The receipt, while in the multiple frame mode of operation, of an unsolicited DM response
with the F bit set to 0 (see § 5.8. 7);
g) The rece ipt while i n the timer re covery condi tion, of a D M response wi th the F bit set to 1.
Reaction of the ISAC-S TE
a) after having checked for validity and non-occurrence of a frame rejection condition, the
error free SABME can be identified after RME-Interrupt by reading the RHCR-register; the
multiple frame est/ti mer recovery discrimination can be done by reading STAR 2: TREC
b) –
c) A TIN-Interrupt occurs (of course MODE: TMD has to have been 1)
d) see section 3
e) see a)
f) see a)
g) see a)
Necessary Software Reactions
The same actions as in section 3 have to be taken. In addition, in case of a) the necessary
discrimination for the software is p ossible by r eading STAR2: WFA while still in au to mode. If
WFA = 1 then V(S) > V(A); if WFA = 0, then V(S) = V(A).
Semicond uctor Group 86
Functional Description
Further Possible Error Conditions
Appendix II of Q.921: Further Possible Error Conditions
Table 8
Q.921
Management Entity Actions for MDL Error Indications
Error Type Error
Code Error
Condition Affect ed
States Network
Management
Action
User
Management
Action
Receipt of
unsolicited
response
A Supervisory
(F = 1) 7 Error log Dependent on
implementation
B DM(F = 1) 7, 8 Error log Dependent on
implementation
C UA (F = 1) 4, 7, 8 TE I removal
proc ed ur e or
TEI check pro-
cedure; then, if
TEI:
– free, re mo ve
TEI
– single, no ac-
tion multiple:
TEI removal
procedure
TEI identity verify
procedure
or
remove TEI
D UA(F = 1) 4, 5, 6, 7, 8
E Receipt of DM
response (F = 0) 7, 8 Error log Dependent on
implementation
Peer initiated
Re-
establishmen
t
F SABME 7, 8 Error log Dependent on
implementation
Unsuccessful
Re-
transmission
(N200 tim es)
G SABME 5 TEI check
procedure;
then, if TEI:
– free, re mo ve
TEI
– single, no ac-
tion multiple:
TEI removal
procedure
TEI identity verify
procedure
or
remove TEI
HDISC 6
I Status Inquiry 8 Error log Dependent on
implementation
Semicond uctor Group 87
Functional Description
Note 1: For the description of the affected states see Annex B.
Note 2: Acco rding to Q.921 § 5.8.5 this error code will never be generated.
Reactions of the ISAC-S TE and Necessary Software Reactions
As the auto mode is only to be used in states 7, 8 and as it has to be switched to non-auto
mode where in states 1-6, we do not have to deal with error code G and H.
A) The ISAC-S does not react at all (our implementation). The software is not informed, as
no action is mandatory according to Q.921.
B) see further Criteria Leading to a Reestablishment"
C) see fu rther Criteria Leading to a Reestablishment
D) see fu rther Criteria Leading to a Reestablishment
E) see further Criteria Leading to a Reestablishment
F see further Criteria Leading to a Reestablishment
I) see further Criteria Leading to a Reestablishment
J) see Frame Rejection Condition
K) see further Criteria Leading to a Reestablishment
L) see Frame Rejection Conditio n
M)
N) see Frame Rejection Condition
O) only internal software timer, no device action.
Conclusion:
For your error-processing with ISAC-S we suggest to implement the software design shown in
the following fi gures 35 through 38 into your interr upt service routine.
Other J N(R) Error 7, 8 Error log Dependent on
implementation
K Receipt of
FRMR
response
7, 8 Error log Dependent on
implementation
L Receipt of non
implemented
frame
4, 5, 6, 7, 8 Error log Dependent on
implementation
M (see
Note 2)Receipt of I-field
not permitted 4, 5, 6, 7, 8 Error log Dependent on
implementation
N Receipt of fra-
me with wrong
size
4, 5, 6, 7, 8 Error log Dependent on
implementation
O N201 Error 4, 5, 6, 7, 8 Error log Dependent on
implementation
Table 8
Q.921
Management Entity Actions for MDL Error Indications (cont’d)
Error Type Error
Code Error
Condition Affect ed
States Network
Management
Action
User
Management
Action
Semicond uctor Group 88
Functional Description
Figure 35
Interrupt Servic e Routin e after RME
ITD05896
RME &
RSTA:RAB
or CRC
?
Y
N
/TIN & /PCE
U-frame
?
RSTA:
which link,
?
auto-mode
Y
N
?
U-frame
==1
0
1
1
=
=
or ISTA:RFO
RSTA:RDO
:
SAPR
RHCR,
Y
N
C/R control field
processing
Not contained
in table 5 of
Q.921 3.6.1
I-frame
Y
N
?
CMDR:RHR
Discard frame cont
time is too slow
software:
Please change your
Futher analysis outside
the auto-mode link
dynamic reaction
260
>
RBCL
RBCH, Re-establishment
of the link
Re-establishment
of the link
CMDR:RMC
Cont. -> Layer 3
Semicond uctor Group 89
Functional Description
Figure 36
Interrupt Service Routines after RPF (top), TIN or PCE (middle left), RSC (middle right),
and XDU or RFO (bottom)
ITD05895
Discard frame cont
RPF &
?
Y
N
/TIN & /PCE
RBCH, CMDR:RHR
CMDR:RMC
Read FIFO
RBCL >528
Note: In this case the software
has to react instantaneously
to the RPF ( < 500 µs)
Re-establishment
of the link
TIN or PCE RSC
variable
Change status
the Deutsche Bundespost
defined in 1
For the congestion procedureNote: TRG of
Please change your software:
Dynamic reaction is too slow
XDU or RFO
refer to the Technical Manual
Semicond uctor Group 90
Functional Description
Figure 37
Interrupt Servic e Routin e after XPR
ITD05893
XPR &
Has a
frame been
?
N
Y
/TIN & /PCE
sent since last
CMDR:XRES
transmitted
N
Y
?
is currently
A frame
ACK1
Last frame
written to XFIFO was
?
Y
N
an I-frame
Y
N
?
SRC * ACK2
ACK1 & ACK2
* Special Request Condition : Last frame written to the XFIFO was an answer to an identity
request following a yet unacknowledged I-frame
Continue writing the contents
of the frame to XFIFO & issuing
Xmit command
End
acknowledged by the peer station
was successful and has been
The transmission of the I-frame
Transmission of the last
frame has finished
Xmit command
Semicond uctor Group 91
Functional Description
Figure 38
Interrupt Servic e Routin e after XMR
ITD05894
frame sent last
XMR &
?
N
Y
/TIN & /PCE
SRC Re-transmit the
frame sent last
Re-transmit the
Ι
-
Semicond uctor Group 92
Functional Description
Figure 39a
MODE NAM
ITD02365
Note: The regeneration of this signal does not affect
the sequence integrity of the I queue.
7
MULTIPLE
FRAME
ESTABLISHED
DL
ESTABLISH
REQUEST REQUEST
RELEASE
DL
DISCARD
I QUEUE
DATA LINK
ESTABLISH
INITIATED
LAYER 3
SET
5
AWAITING
ESTABLISHM.
PEER
RECEIVER
BUSY
STAR:RRNR
I FRAME
QUEUED UPREQUEST
DL-DATA
I QUEUE
DISCARD I QUEUE
PUT IN
RC = 0
P = 1 I FRAME
QUEUED UP STAR2:WFA
(V)S = V(A) + K
ESTABLISHED
FRAME
MULTIPLE
7
TX DISC
XFIFO
CMDR XTF
RESTART T200
STOP T203
GET NEXT
I QUEUE
ENTRY
XFIFO
P = 0
COMMAND
TXI
CMDR:XIF
RELEASE
AWAITING
6
MODE NAM
V(S) = V(S) + 1
CLEAR
ACKNOWLEDGE
PENDING
START T200
7
MULTIPLE
FRAME
ESTABLISHED
QUEUED UP
I FRAME
YES
NO
NO
YES
T200
RUNNING
NO
YES
STOP T203
Semicond uctor Group 93
Functional Description
Figure 39b
DEACTIVATION
PERSISTENT
MDL
REMOVE
REQUEST
CMDR STI
EXPIRY
T203
TIMER
TIMER
T200
EXPIRY
7
MULTIPLE
FRAME
ESTABLISHED
QUEUES
I AND UI
DISCARD DISCARD
I AND UI
QUEUES
INDICATION
DL RELEASE DL RELEASE
INDICATION
STOP T203
STOP T200 STOP T200
STOP T203
UNASSIGNED
TEI
14
TEI
ASSIGNED
8
TIMER
RECOVERY STAR2:
TREC
TRANSMIT
ENQUIRY
RC = RC + 1
TREC
STAR2:
RECOVERY
TIMER
8
ITD02366
TRANSMIT
ENQUIRY
RC = 0
PEER
BUSY
I FRAME
TRANSMITTED
GET LAST
V(S) = V(S) - 1
P = 1
COMMAND
TX I
V(S) = V(S) + 1
PENDING
ACKNOWLEDGE
CLEAR
START T200
YES RC = 0
NO
Semicond uctor Group 94
Functional Description
Figure 39c
ITD02367
7
MULTIPLE
FRAME
ESTABLISHED
I QUEUE
DISCARD
STAR2:WFA = 0
V(S) = V(A)
ESTABLISHED
FRAME
MULTIPLE
7
TX UA
XFIFO
CMDR XTF
I QUEUE
DISCARD
NO
YES
RME
SABME
RCHR: RCHR:
DISC
RME
RCHR:
UA
RME
F=P MDL-ERROR
INDICATION
(C,D)
CMDR XTF
XFIFO
TX UA
CLEAR
EXCEPTION
CONDITIONS
(F)
INDICATION
MDL-ERROR
DL
ESTABLISH
INDICATION
DL-RELEASE
INDICATION
CMDR:RHR;XRES
STOP T203
STOP T200
STOP T200
STOP T203
ASSIGNED
TEI
4
MODE NAM
ESTABLISHED
FRAME
MULTIPLE
7
WFA
STAR2:
STORE
V(R) = 0
V(A) = 0
V(S) = 0
F = P
Semicond uctor Group 95
Functional Description
Figure 39d
ITD02368
ESTABLISHED
FRAME
MULTIPLE
7
RHCR:
DM
RME
F = 1
RHCR
MDL-ERROR
INDICATION
(E)
ESTABLISH
DATA LINK
(B)
INDICATION
MDL-ERROR
ESTABLISHED
FRAME
MULTIPLE
7
BUSY
RECEIVER
SET OWN
YES
NO NO
YES
CLEAR
RECEIVER
BUSY
CMDR:RNR = 1
BUSY
RECEIVER
SET OWN
STAR:XRNR
ESTABLISHM.
AWAITING
5
MODE NAM
F = 0
LAYER 3
CLEAR
INITIATED
PENDING
CLEAR
ACKNOWLEDGE ACKNOWLEDGE
CLEAR
PENDING
F = 0
STAR:XRNR
CLEAR OWN
RECEIVER
BUSY
CMDR:RNR = 0
BUSY
RECEIVER
CLEAR
NO
YES
CLEAR OWN
RECEIVER
BUSY
ESTABLISHED
FRAME
MULTIPLE
7
Note: These signals are generated outside of this SDL representation,
and may be generated by the connection management entity.
TX RNR
RESPONSE TX RR
RESPONSE
Semicond uctor Group 96
Functional Description
Figure 39e
ESTABLISHED
FRAME
MULTIPLE
7
RR
RECEIVER
CLEAR PEER
BUSY STAR:RRNR
RSC /
COMMAND NO
YES
F = 1
YES
NO
P = 1
YES
NO
ENQUIRY
RESPONSE STAR2:SDET
1 2
NO
F = 1
STAR2:SDET
RESPONSE
ENQUIRY
P = 1
NO
YES
YES
NO COMMAND
RSC /
STAR:RRNR
BUSY
CLEAR PEER
RECEIVER
REJ
YES
ITD05656
Figure 39 f Figure 39 f
(A)
INDICATION
MDL-ERROR-
(A)
INDICATION
MDL-ERROR-
Semicond uctor Group 97
Functional Description
Figure 39f
1 2
XPR /
STAR2:WFA
V(A) = N(R)
RETRANS-
INVOKE
MISSION
XMR /
ESTABLISHED
FRAME
MULTIPLE
7
RECOVERY
N(R) ERROR PCE
ESTABLISHM.
AWAITING
5
MODE NAM
YES
NONO
YES
V(A) N(R) V(S)
N(R) = V(S)
YES
NO
STOP T200
V(A) = N(R) STAR2:WFA
XPR / YES N(R) = V(A)
ESTABLISHED
FRAME
MULTIPLE
7
NO
ITD02370
RESTART T200
V(A) = N(R)
START T203
START T203
STOP T200
_
<
_
<
V(A) N(R) V(S)
_
<
_
<
Semicond uctor Group 98
Functional Description
Figure 39g
ESTABLISHED
FRAME
MULTIPLE
7
RNR
RECEIVER
SET PEER
BUSY STAR:RRNR
RSC /
COMMAND NO
YES F = 1
YES
NO
P = 1
YES
NO
ENQUIRY
RESPONSE STAR2:SDET
RHCR:
FRMR
RME
(K)
MDL-ERROR
INDICATION
ESTABLISH
DATA LINK
LAYER 3
CLEAR
INITIATED
ESTABLISHM.
AWAITING
5
MODE NAM
NO
YES
V(A) = N(R)
STAR2:WFA
XPR /
RESTART T200
RC = 0
ESTABLISHED
FRAME
MULTIPLE
7
N(R)
ERROR
RECOVERY
PCE
ESTABLISHM.
AWAITING
5
MODE NAM
ITD02371
STOP T203
MDL-ERROR-
INDICATION
(A)
V(A) N(R) V(S)
_
<
_
<
Semicond uctor Group 99
Functional Description
Figure 39h
ESTABLISHED
FRAME
MULTIPLE
7
COMMAND
I
OWN
RECEIVER
BUSY
YES
NO
N(S) = V(R)
V(R) = V(R) + 1
NO
YES
INFORMATION
DISCARD
EXCEPTION
CLEAR REJECT EXCEPTION
REJECT
RFIFO, RHCR
RME
DL-DATA
INDICATION P = 1
P = 1
ACKNOWLEDGE
PENDING F = P
YES
YES
YES
NO
NO
PENDING
ACKNOWLEDGE
SET
ACKNOWLEDGE
PENDING PENDING
ACKNOWLEDGE
CLEAR
TX RR
STAR2:SDET
STAR2:SDET
TX REJ
CLEAR
ACKNOWLEDGE
PENDING
F = P
EXCEPTION
REJECT
SET
3
YES
NOTE 1
F = 1
PENDING
ACKNOWLEDGE
CLEAR
TX RNR
STAR2:SDET
YES
P = 1
DISCARD
INFORMATION
NO
NO
NO
NOTE 2
Note 2: This SDL representation does not include the optional procedure in Appendix I.
ITD05657
Figure 39 i
Note 1: Processing of acknowledge pending is descripted on figure 39 i
Semicond uctor Group 100
Functional Description
Figure 39i
3
ERROR
N(R)
RECOVERY
PCE
ESTABLISHM.
AWAITING
5
MODE NAM
NO
YES
YES
NO
STOP T200
V(A) = N(R) STAR2:WFA
XPR / N(R) = V(S)
ESTABLISHED
FRAME
MULTIPLE
7
YES
ITD02373
PEER
RECEIVER
BUSY
XPR /
STAR2:WFA
V(A) = N(R)
NO
N(R) = V(A)
NO
YES
V(A) = N(R)
RESTART T200
RESTART T203
V(A) N(R) V(S)
<
__
<
_
<
_
<
Semicond uctor Group 101
Functional Description
Figure 39j
ESTABLISHED
FRAME
MULTIPLE
7
PENDING
ACKNOWLEDGE
ACKNOWLEDGE
PENDING
CLEAR
ACKNOWLEDGE
PENDING
NO
YES
F = 0
TX RR
STAR2:SDET
ESTABLISHED
FRAME
MULTIPLE
7
ITD02374
Semicond uctor Group 102
Functional Description
Figure 40a
MODE NAM
ITD02375
8
TIMER
RECOVERY
DL
ESTABLISH
REQUEST REQUEST
DL
DISCARD
I QUEUE
DATA LINK
ESTABLISH
INITIATED
LAYER 3
SET
5
AWAITING
ESTABLISHM.
I FRAME
QUEUED UPREQUEST
DL-DATA
I QUEUE
DISCARD I QUEUE
PUT IN
RC = 0
P = 1 I FRAME
QUEUED UP
TX DISC
XFIFO
CMDR XTF
RESTART T200
RELEASE
AWAITING
6
MODE NAM
RECOVERY
TIMER
8
ESTABLISH
Semicond uctor Group 103
Functional Description
Figure 40b
DEACTIVATION
PERSISTENT
MDL
REMOVE
REQUEST
TIMER
T200
EXPIRY
QUEUES
I AND UI
DISCARD DISCARD
I AND UI
QUEUES
INDICATION
DL-RELEASE DL-RELEASE
INDICATION
STOP T200 STOP T200
TRANSMIT
ENQUIRY
RC = RC + 1
RECOVERY
TIMER
8
ITD02376
8
TIMER
RECOVERY
TIMR TIMR
UNASSIGNED
TEI
1
MODE NAM
ASSIGNED
TEI
4
MODE NAM
INDICATION(I)
MDL-ERROR
TIN
ESTABLISH
DATA LINK
CLEAR
LAYER 3
INITIATED
MODE NAM
5
AWAITING
ESTABLISHM.
RC = N200 YES
NO
NO
V(S) = V(A)
YES
NO
YES
START T200
CLEAR
ACKNOWLEDGE
PENDING
V(S) = V(S) + 1
TX I
COMMAND
P = 1
V(S) = V(S) - 1
GET LAST
TRANSMITTED
I FRAME
BUSY
PEER
Semicond uctor Group 104
Functional Description
Figure 40c
ITD02377
8
TIMER
RECOVERY
I QUEUE
DISCARD
STAR2:WFA = 0
V(S) = V(A)
TX UA
XFIFO
CMDR XTF
I QUEUE
DISCARD
NO
YES
RME
SABME
RHCR: RHCR:
DISC
RME
RHCR:
UA
RME
F = P MDL-ERROR
INDICATION
(C, D)
CMDR XTF
XFIFO
TX UA
CLEAR
EXCEPTION
CONDITIONS
(F)
INDICATION
MDL-ERROR
DL
ESTABLISH
INDICATION
DL-RELEASE
INDICATION
CMDR:RHR;XRES
STOP T200
STOP T200
ASSIGNED
TEI
4
MODE NAM
ESTABLISHED
FRAME
MULTIPLE
7
WFA
STAR2:
STORE
V(R) = 0
V(A) = 0
V(S) = 0
F = P RECOVERY
TIMER
8
STAR2:TREC
START T203
Semicond uctor Group 105
Functional Description
Figure 40d
ITD02378
RHCR:
DM
RME
F = 1
RHCR
MDL-ERROR
INDICATION
(E)
ESTABLISH
DATA LINK
(B)
INDICATION
MDL-ERROR
BUSY
RECEIVER
SET OWN
YES
NO NO
YES
CLEAR
RECEIVER
BUSY
CMDR:RNR = 1
BUSY
RECEIVER
SET OWN
STAR:XRNR
ESTABLISHM.
AWAITING
5
MODE NAM
F = 0
LAYER 3
CLEAR
INITIATED
PENDING
CLEAR
ACKNOWLEDGE ACKNOWLEDGE
CLEAR
PENDING
F = 0
STAR:XRNR
CLEAR OWN
RECEIVER
BUSY
CMDR:RNR = 0
BUSY
RECEIVER
OWN
NO
YES
CLEAR OWN
RECEIVER
BUSY
Note: These signals are generated outside of this SDL representation,
and may be generated by the connection management entity.
RECOVERY
TIMER
8
RECOVERY
TIMER
8
TX RNR
RESPONSE TX RR
RESPONSE
Semicond uctor Group 106
Functional Description
Figure 40e
RR
RECEIVER
CLEAR PEER
BUSY STAR:RRNR
RSC /
COMMAND NO
YES F = 1
YES
NO
P = 1
YES
NO
ENQUIRY
RESPONSE STAR2:SDET
REJ
RECOVERY
TIMER
8
XPR /
STAR2:WFA
V(A)=N(R)
RETRANS-
INVOKE
MISSION
XMR /
ESTABLISHED
FRAME
MULTIPLE
7
RECOVERY
N(R) ERROR PCE
ESTABLISHM.
AWAITING
5
MODE NAM
YES
NO
YES
NO
V(A) = N(R) STAR2:WFA
XPR /
ITD02379
RECOVERY
TIMER
8
STAR2:TREC
START T203
STOP T200
V(A) N(R) V(S)
<
__
<
_
<
_
<
V(A) N(R) V(S)
_
<
_
<
__
<<
Semicond uctor Group 107
Functional Description
Figure 40f
RNR
BUSY STAR:RRNR
RSC /
COMMAND NO
YES F = 1
YES
NO
P = 1
YES
NO
ENQUIRY
RESPONSE STAR2:SDET
RCHR:
FRMR
RME
(K)
MDL-ERROR
INDICATION
ESTABLISH
DATA LINK
LAYER 3
CLEAR
INITIATED
ESTABLISHM.
AWAITING
5
MODE NAM
NO
YES
V(A) = N(R)
STAR2:WFA
XPR /
ESTABLISHED
FRAME
MULTIPLE
7
N(R)
ERROR
RECOVERY
PCE
ESTABLISHM.
AWAITING
5
MODE NAM
ITD02380
RECOVERY
TIMER
8
YES
NO
RECOVERY
TIMER
8
STAR2:TREC
XMR /
MISSION
RETRANS-
INVOKE
RESTART T200
RC = 0
XPR /
STAR2:WFA
V(A) = N(R)
V(A) N(R) V(S)
_
<
_
<
V(A) N(R) V(S)
_
<
_
<
Semicond uctor Group 108
Functional Description
Figure 40g
RECOVERY
TIMER
8
COMMAND
I
OWN
RECEIVER
BUSY
YES
NO
N(S) = V(S)
V(R) = V(R) + 1
NO
YES
INFORMATION
DISCARD
EXCEPTION
CLEAR REJECT EXCEPTION
REJECT
RFIFO, RHCR
RME
DL-DATA
INDICATION P = 1
P = 1
ACKNOWLEDGE
PENDING F = P
YES
YES
YES
NO
NO
PENDING
ACKNOWLEDGE
SET
ACKNOWLEDGE
PENDING PENDING
ACKNOWLEDGE
CLEAR
TX RR
STAR2:SDET
STAR2:SDET
TX REJ
CLEAR
ACKNOWLEDGE
PENDING
F = P
EXCEPTION
REJECT
SET
4
YES
NOTE 1
F = 1
PENDING
ACKNOWLEDGE
CLEAR
TX RNR
STAR2:SDET
YES
P = 1
DISCARD
INFORMATION
NO
NO
NO
NOTE 2
Note 1: Processing of acknowledge pending is descripted on figure
Note 2: This SDL representation does not include the optional procedure in Appendix I.
ITD05658
Figure 40 h
40 i
Semicond uctor Group 109
Functional Description
Figure 40h
Figure 40i
4
ERROR
N(R)
RECOVERY
PCE
ESTABLISHM.
AWAITING
5
MODE NAM
NO
YES
ITD02382
XPR /
STAR2:WFA
V(A) = N(R)
RECOVERY
TIMER
8
V(A) N(R) V(S)
_
<
_
<
RECOVERY
TIMER
8
PENDING
ACKNOWLEDGE
ACKNOWLEDGE
PENDING
CLEAR
ACKNOWLEDGE
PENDING
NO
YES
F = 0
TX RR
STAR2:SDET
ITD02383
8
TIMER
RECOVERY
Semicond uctor Group 110
Functional Description
Figure 41a
(NOTE 1)
STATES
RELEVANT
REQUEST
UNIT DATA
DL UI
FRAME
QUEUED UP
RME
UI COMMAND
RHCR
UI QUEUE
PLACE IN REMOVE UI
FRAME FROM
QUEUE
DL
UNIT DATA
INDICATION
QUEUED UP
FRAME
UI P = 0 NOTE 2
NOTE 2
NOTE 2
TX UI
COMMAND
CMDR: XTF
XFIFO
ITD02384
Note 1: The relevant states are as follows
4 TEI-assigned
5 Awaiting-establishement
6 Awaiting-release
7 Multiple-frame-established
8 Timer-recovery
Note 2: The data link layer returns to the state it was in prior to the events shown.
Semicond uctor Group 111
Functional Description
Figure 41b
(NOTE 1)
STATES
RELEVANT
INFO NOT
PERMITTED
(X)
CLEAR
LAYER 3
INITIATED
MDL-ERROR
INDICATION
(L,M,N,O)
ITD02385
Note 1: The relevant states are as follows
7 Multiple-frame-established
8 Timer-recovery
ERROR (W)
FIELD
CONTROL
(X)
LENGHT
INCORRECT 1 FRAME
TOO LONG
(Y)
ESTABLISH
DATA LINK
ESTABLISHM.
AWAITING
5
PCE /
Semicond uctor Group 112
Functional Description
Figure 41c
(NOTE 1)
STATES
RELEVANT
FIELD
CONTROL
ITD02577
ERROR (W) (X)
PERMITTED
INFO NOT I FRAME
TOO LONG
(Y) (X)
INCORRECT
LENGTH
(L, M, N, O)
INDICATION
MDL-ERROR-
NOTE 2
Note 1:
Note 2:
The relevant states are as follows:
4 TEI-assigned
5 Awaiting-establishment
6 Awaiting-release
The data link layer returns to the state
it was in prior to the events shown
Semicond uctor Group 113
Functional Description
Figure 41d
ITD02386
N(R)
ERROR
RECOVERY
INDICATION(J)
MDL-ERROR
PCE
DATA LINK
ESTABLISH TRANSMIT
ENQUIRY
CONDITIONS
EXCEPTION
CLEAR
CLEAR
EXCEPTION
CONDITION
CMDR:RHR,XRES
MODE: NAM
CLEAR PEER
RECEIVER
BUSY
CMDR:RHR,XRES
P = 1
ESTABLISH
DATA LINK P = 1
RC = 0
EXCEPTION
REJECT
CLEAR
BUSY
RECEIVER
OWN
CLEAR
LAYER 3
INITIATED
CMDR:RNR = 0
BUSY
RECEIVER
CLEAR OWN
CMDR:XTF
XFIFO
TX SABME
COMMAND
TX RR TX RNR
COMMAND
RESTART T200
STOP T203 CLEAR
ACKNOWLEDGE
PENDING
PENDING
ACKNOWLEDGE
CLEAR
YES
NO
START T200
Semicond uctor Group 114
Functional Description
Figure 41e
ITD02387
ENQUIRY
RESPONSE
F = 1
BUSY
RECEIVER
OWN
RESPONSE
TX RR TX RNR
RESPONSE
PENDING
ACKNOWLEDGE
CLEAR
YES
NO
RETRANS-
INVOKE
MISSION
V(S) = N(R)
YES
NO
V(S) =V(S) - 1
XMR
QUEUED UP
I FRAME
STAR2:SDET STAR2:SDET
BACK TRACK
ALONG
I QUEUE
NOTE
Note: The generation of the correct number of signals in order to cause the required
retransmission of I frames does not alter their sequence integrity
.
Semicond uctor Group 115
Operational Description
3 Operational Description
The ISAC-S TE, designed for the connection of subscribers to an ISDN using a standard S/T
interface, has the following application, corresponding to the operating mode explained in
chapter 2:
Terminal Equipment TE1, TA
e.g. ISDN-feature tele pho ne ,
ISDN-voice/data workstation
Terminal Adapter for non-ISDN terminals (TE2)
3.1 Microprocessor Interface Operation
The ISAC-S TE is programmed via an 8-bit parallel microcontroller interface. Easy and fast
microp rocesso r access is provide d by 8- bit addr ess dec oding on the chi p. Depe nding on the
chip package (P-DIP-40, P-LCC-44, P-MQFP-64) either one or three types of µP buses are
provided:
P-DIP-40 package:
The ISAC-S TE microcontroller interface is of the Siemens/Intel multiplexed address/data
bus type with control signals CS, WR, RD, ALE.
P-LCC-44/P-MQFP-64 package:
The ISA C-S TE mic r ocontrolle r interface can be selected to be eit her of the
(1) – Motorola type with control signals CS, R/W, DS
(2) – Siemens/Intel non-multiplexed bus type with control signals CS, WR, RD
(3) – or of the Siemens/Intel multiplexed address/data bus type with control
signals CS, WR, RD, ALE.
The selection is per formed via pin ALE as follows:
ALE tied to VDD ⇒(1)
ALE tied to VSS ⇒(2)
Edge on ALE ⇒(3).
The occurrence of an edge on ALE, either positive or negative, at any time during the operation
immediately selects interface type (3). A return to one of the other interface types is possible
only if a hardware reset is issued.
Notes: 1) If the multiplexed address/data bus type (3) is selected, the unused address pins
A0-A5 are internally pulled low and may thus be left open. It is however
recommended to tie the unused input pins to a VDD voltage level.
2) If the non-multiplexed bus types (1) or (2) are selected, th e EAW line can no lo nger
be used since pin 10 EA W/A5 ha s the functio n of an add ress pin (P LCC-4 4 only ).
Semicond uctor Group 116
Operational Description
The microprocessor interface signals are summarized in table 9.
Table 9
µP Interface of the ISAC®-S TE
Pin No.
P-DIP-40 Pin No.
P-LCC-44 Function
37
38
39
40
1
2
3
4
41
42
43
44
1
2
3
4
Multiplexed Bus Mode: Address/Data
bus. Transfers addresses from the µP
system to the ISAC-S TE and data
between the µP system and the
ISAC-S TE.
Non-Multiplexed Bus Mode: Data bus.
Transfers d ata between the µP system and
the ISAC-S TE.
34 37 Chip Select. A 0 (" low") on this line sele cts
the ISAC-S TE for a read/write operation.
35
38
38
Read/Write. A 1 ("high"), identifies a valid
µP access as a read operation. A 0,
identifies a valid µP access as a write
operation (Mot orola bus mode).
Write. This signal indicates a write
operation (Siemens/Intel bus mode).
36
39
39
Data Strobe. The rising edge marks the
end of a valid read or write operation
(Motorola bus mode).
Read. This signal indicates a read
operation (Siemens/Intel bus mode).
20 23 Interrupt Request. The signal is activated
when the ISAC-S TE requ ests an in terrupt.
It is an open drain output.
33 36 Address Latch Enabl e. A high on this line
indicates an address on the external
address bus (multiplexed bus type only).
ALE also selects interface mode.
40 Address Bit 0 (non-multiplexed bus type).
6Address Bit 1 (non-multiplexed bus type).
5Address Bit 2 (non-multiplexed bus type).
18 Address Bit 3 (non-multiplexed bus type).
17 Address Bit 4 (non-multiplexed bus type).
10 Address Bit 5 (non-multiplexed bus type).
Input (I)
Output (O)
Open Drain
(OD)
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I
I
I
I
I
OD
I
I
I
I
I
I
I
Symbol
AD0/D0
AD1/D1
AD2/D2
AD3/D3
AD4/D4
AD5/D5
AD6/D6
AD7/D7
CS
R/W
WR
DS
RD
INT
ALE
A0
A1
A2
A3
A4
A5
Pin No.
P-MQFP-64
37
38
39
40
41
42
43
44
27
28
28
29
29
8
26
30
51
50
64
63
55
Semicond uctor Group 117
Operational Description
3.2 Interrupt Structure and Logic
Since the ISAC-S TE provides only one interrupt request output (INT), the cause of an interrupt
is determined by the microprocessor by reading the Interrupt Status Register ISTA. In this
register, seven interrupt sources can be directly read. The LSB of ISTA points to eight non-
critical interrupt sources which are indicated in the Extended Interrupt Register EXIR
(figure 42).
Figure 42
ISAC®-S TE Interrupt Structure
ITD02578
RME
RPF
RSC
XPR
TIN
CISQ
SIN
EXI EXI
SIN
CISQ
TIN
XPR
RSC
RPF
RME
MASK ISTA XMR
XDU
PCE
RFO
SOV
MOS
SAW
WOV
EXIR
MOSRMOCR
MDR1
MER1
MDA1
MAB1
MDR0
MER0
MDA0
MAB0
MXE0
MRE0
MXE1
MRE1
INT
CIR0
SQC
BAS
CIC0
CIC1
SQIE
CI1E
SQXR
CIR1
SQRR
C
O
D
R
0
only
R
IOM -2
Semicond uctor Group 118
Operational Description
A read of the ISTA register clears all bits except EXI and CISQ. CISQ is cleared by reading
CIR0. A read of EXIR clears the EXI bit in ISTA as well as the EXIR register.
When all bits in ISTA are cleared, the interrupt line (INT) is deactivated.
Each interrupt source in ISTA register can be selectively masked by setting to "1" the
corres pond in g bit in MA SK. Maske d inte rru pt s tatus bits are no t indic at ed whe n ISTA is read .
Instead, th ey rema in in tern ally stored an d pend ing, u ntil the mask bit i s reset to zero . Readi ng
the ISTA while a mask bit is active has no effect on the pending interrupt.
In the event of an extended interrupt and of a C/I- or S/Q channel change, EXI and CISQ are
set even when the corresponding mask bits in MASK are active, but no interrupt (INT) is
generated.
Except for CISQ and MOS all interrupt sources are directly determined by a read of ISTA and
(possibly) EXIR.
CISQ-Interrupt Logic
– A CISQ interrup t may o riginate
– from a change in the received S/Q code (SQC)
– from a change in the received C/I channel 0 code (CIC0)
or (in the case of IOM-2 terminal mode only)
– from a change in the received C/I channel 1 code (CIC1).
The three corresponding status bits SQC, CIC0 and CIC1 are read in the CIR0 register. SQC
and CIC1 can be individually disabled by clearing the enable bit SQIE (SQXR register) or,
respectively, CI1E (SQXR register). In this case the occurrence of a code change in SQRR/
CIR1 will not be displayed by SQC/CIC1 until the corresponding enable bit has been set to one.
Bits SQC, CIC0 and CIC1 are cleared by a read of CIR0.
An interrupt status is indicated every time a valid new code is loaded in SQRR, CIR0 or CIR1.
But in case of a code change, the new code is not loaded until the previous contents have been
read. When thi s is don e and a s econd co de chan ge has a lready oc curred , a new interrupt is
immediately generated and the new code replaces the previous one in the register. The code
registers are buffered with a FIFO size of two. Thus, if several consecutive codes are detected,
only the first and the last code is obtained at the first and second register read, respectively.
Semicond uctor Group 119
Operational Description
MOS-Interrupt Logic
The MONITOR Data Receive (MDR) and the MONITOR End of Reception (MER) interrupt
status bits have two enable bits, MONITOR Receive interrupt Enable (MRE) and MR bit
Control (MRC). The MONITOR channel Data Acknowledged (MDA) and MONITOR channel
Data Ab or t (MAB ) int e rrupt sta tus bi ts ha v e a co mmon en ab le bit MONI TOR In t err upt Enab le
(MXE).
MRE prevents the occurrence of the MDR status, including when the first byte of a packet is
received. When MRE is active (1) but MRC is inactive, the MDR-interrupt status is generated
only for the first byte of a receive packet. When both MRE and MRC are active, MDR is
generated and all receive d monitor bytes – marked by a 1-to-0 transition in MX bit – are stored.
(Additionally, an active MRC enables the control of the MR handshake bit according to the
MONITOR channel protocol.)
Control of Edge-Triggered Interrupt Controllers
The INT output is level active. It stays active until all interrupt sources have been serviced. If
a new status bit is set while an interrupt is serviced, the INT line stays active. This may cause
problems if the ISAC-S TE is connected to edge-triggered interrupt controllers (figure 43).
To avoid these problems, it is recommended to mask all interrupts at the end of the interrupt
service pr og ram a nd to ena bl e th e inte rrup ts ag ai n. Th is i s do n e by w ritin g FFH to the MASK
register and to write back the old value of the MASK register (figure 44).
Semicond uctor Group 120
Operational Description
Figure 43
INT Handling
Figure 44
Service Program for Edge-Triggered Interrupt Controllers
➀A status bit is set. This causes an interrupt.
➁The microprocessor starts its service routine and reads the status registers.
➂A new status bit is set before the first status bit has been read.
➃The first status bit is read.
➄The INT output stays active but the interru pt controller will not serve the interrupt
(edge tr iggere d) .
ITD05430
1
2
3
45
INT
➀ to ➃ see above
➄’ FF’ is written to the MAS K register. This masks all interrupts and returns the INT
output to its inactive state.
➅The old value is written to the MASK register. This will activate the INT output if
an interrupt source is still active.
➆The microp rocessor starts a new interrupt service pro gra m.
➇The last status bit is read.
➈The INT output is inactive.
ITD05431
1
2
3
4
INT
56789
Semicond uctor Group 121
Operational Description
Figure 45
Timing of INT Pin
The INT line is switched with the rising edge of DCL. If no pending interrupts are internally
stored, a r eading of ISTA re spec tively EX IR or CIR 0 switch es the I NT line to hi gh as indi cated
in figure 45.
3.3 Control of Layer 1
3.3.1 Activation/Deactivation of IOM® Interface
The IOM interface can be switched off in the inactive state, reducing power consumption to a
minimu m. In this deactivated state the clock line is low and the data li nes ar e high.
The IOM interface can be kept active while the S interface is deactivated by setting the CFS
bit to "0" (SQXR register). This is the case after a hardware reset. If the IOM interface should
be switched off while the S interface is deactivated, the CFS bit should be set to "1". In this
case the internal oscillator is disabled when no signal (info 0) is present on the S bus. If the TE
wants to activa te the line, it has first to a ctivate the IO M interface e ither by usin g the "Software
Power-Up" function (SPCR:SPU bit) or by setting the CFS bit to "0" again.
For the TE case the deactivation procedure is shown in figure 46. After detecting the code DIU
(Deactivate Indication Upstream, i.e. from TE to NT/LT-S) the layer 1 of the ISAC-S TE
responds by transmitting DID (Deactivate Indication Downstream) during subsequent frames
and stops the timing sig nals synchron ously with th e end of the la st C/I (C/I0) channel bit o f the
fourth frame.
ITD02388
~
~~
~~
~
DCL
INT
RD
Semicond uctor Group 122
Operational Description
Figure 46
Deactivation of the IOM® Interface
The clock pulses will be enabled again when the IDP1 line is pulled low (bit SPU, SPCR
register) i.e. the C/I command TIM = "0000" is received by layer 1, or when a non-zero level
on the S-line interface is detected. The clocks are turned on after approximately 0.2 to 4 ms
depending on the capacitances on XTAL 1/2.
DCL is activat ed such that its firs t rising edge occur s with t he be ginn ing of the b it fo llowin g the
C/I (C/I0) channel.
After the clocks have been enabled this is indicated by the PU code in the C/I channel and,
consequently, by a CISQ interrupt. The IDP1 line may be released by resetting the Software
Power-Up bit SPCR:SPU=0, and the C/I code written in CIX0 is outpu t on IDP1.
ITD05963
DIU DIU DIU DIU DIU DIU DIU DIU DIU
DIDDIDDIDDIDDRDRDRDRDR
FSC
IDP1
IDP0
Deactivated
D
B2 MONO DB1
CIO
CIO
DCL
(DU)
(DD)
R
IOM -2
Semicond uctor Group 123
Operational Description
Figure 47
Activation of the IOM® Interface (CFS=1, register SQXR)
ITD05962
~
~~
~~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~~
~
~
~
FSC
IDP1
IDP0
FSC
IDP1
IDP0
DCL
SPU=1 0=SPU
CIS0 = TIMCISQ
Int.
TIM TIM TIM
PU PU PU PU PU
B1
B1MXMR
0.2 to 4 ms
132 x DCL
Note:IDP0 is input and IDP1 is low during :IDC =1
0=IDC
:
IDP0 is low and IDP1 is input during
(DU)
(DD)
(DU)
(DD)
R
IOM -CH1
R
IOM -CH2
R
IOM -CH1 IOM
R
-CH2
R
IOM -CH1 if SQXR
-CH1 if SQXR
IOM
R
Semicond uctor Group 124
Operational Description
The ISAC -S TE sup plies IOM t iming sig nals as long as there is no DIU command in the C /I (C/
I0) channel. If timing signals are no longer required and activation is not yet requested, this is
indicated by programming DIU in the CIX0 register.
As an alte rnative to act ivation via IDP1 (DU ), the IOM int erface can be activated by se tting the
CFS bit to "0". The activation of FSC1 and DCL in this case is similar to figure 47. Note that
the IOM interface can be deactivated through DIU (power-down state, figur e 46) only if CFS
is set to logical "1".
3.3.2 Activation/Deactivation of S/T Interface
Assumin g the ISAC-S TE has been ini tializ ed with the re quire d features o f the appli catio n, it is
now ready to transmit and receive messages in the D channel (LAPD support).
But as a prerequisite, the layer 1 has to be activated.
The layer-1 functions are controlled by commands issued via the CIXR/CIX0 register. These
commands, sent over the IOM C/I channel 0 to layer 1, trigger certain procedures, such as
activation/deactivation, switching of test loops and transmission of special pulse patterns.
These are governed by layer-1 state diagrams in accordance with CCITT I.430. Responses
from layer 1 are obtained by reading the CIRR/CIR0 register after a CISQ interrupt (ISTA).
The state diagrams are shown in figure 49. The activation/deactivation implemented by the
ISAC-S TE agrees with the requirements set forth in CCITT recommendations. State identifiers
F1-F8 (TE) are in accordance with CCITT I.430.
In the state diagrams a notation is employed which explicitly specifies the inputs and outputs
on the S interface and in the C/I channel: see figure 48.
Figure 48
ITD05676
ii
Cmd.Ind.
State
Ι
S-INFO
C/
Unconditional
Transition
XY
OUT IN
-S TEISAC
R
-S TEISAC
R
Semicond uctor Group 125
Operational Description
3.3.2.1 Layer-1 Command/Indication Codes and State Diagrams
Table 10
Commands
Important Note: When in the activated state (AI8/AI10 indication) the 2B+D channels are
only transferred from the IOM-2 to the S/T interface if an "Activate Request"
command is written to the CIX0 register.
RemarksCommand (upstream) Abbr. Code
Activation of all output clocks is requestedTiming TIM 0000
(x)Reset RS 0001
Transmission of pseudo-ternary pulses at
96-kHz frequency (x)
Send continuous zeros SCZ 0100
Transmission of pseudo-ternary pulses at
2-kHz frequency (x)
Send single zeros SSZ 0010
Activation command, set D-channel
priority to 8 (see note)
Activate request, set priority 8 AR8 1000
Activation command, set D-channel
priority to 10 (see note)
Activate request, set priority 10 AR10 1001
Activation of test loop 3 (x)Activate re quest loop ARL 1010
IOM-interface clocks can be disabledDeactivate indication upstream DIU 1111
(x) unconditional commands
Semicond uctor Group 126
Operational Description
Table 11
Indications
RemarksIndication (downstream) Abbr. Code
IOM clocking is providedPower-up PU 0111
Deactivation request by S interfaceDeactivate request DR 0000
Either: (pin RST = 1 a nd bit CFS = 0) or RSError indication EI 0110
Signal received, receiver not synch ronousLevel detected RSY 0100
Info 2 receivedActivate re qu est dow n str ea m ARD 1000
Test loop 3 activated or continuous zeros
transmitted
Test indication TI 1010
Level detected during test loopAwake test indication ATI 1011
Info 4 received, D-channel priority is 8 or 9Activate indication with
priority class 8 AI8 1100
Info 4 received, D-channel priority is 10 or
11
Activate indica ti on with
priority class 10 AI10 1101
Clocks will be disabled in TE, quiescent
state
Deactivate indication
downstream DID 1111
Semicond uctor Group 127
Operational Description
F3 Power-Down
This is the deactivated state of the physical protocol. The receive line awake unit is active
except dur i ng an R ST pu lse. Clocks a re disa bled if SQX R :CFS=1. The po wer con sumpt ion in
this state is approx imately 80 mW when the clo ck is running, and 8 mW otherwise.
F3 Power-Up
This state is identical to "F3 power-down", except for the C/I-output message. The state is
invoked by a C/I command TIM = "0000" (or IDP1 static low). After the subsequent activation
of the clocks the PU message is outputted. This occurs 0.5 ms to 4 ms after application of TIM,
depending on crystal capacitances.
F3 Pending Deactivation
The ISAC-S TE reaches this state after receiving INFO0 (from states F5 to F8) for 16 ms (64
frames ). This t ime co nstan t is a "f lywhee l" to p rev ent ac cide nta l deac tivat ion. From t his state
an activation is only possible from the line (transition "F3 pend. deact." to "F5
unsynchronized"). A power-down state may be reached only after receiving DIU.
F4 Pending Activation
Activation has been requested from the terminal, INFO1 is transmitted, INFO0 is still received,
"Power-Up" is transmitted in the C/I channel. This state is stable: timer T3 (I.430) is to be
implemented in software.
F5 Unsynchronized
At the reception of any signal from the NT, the ISAC-S TE ceases to transmit INFO1 and awaits
identification of INFO2 or INFO4. This state is reached at most 50 µs after a signal different
from INFO0 is present at the receiver of the ISAC-S TE.
F6 Synchronized
When th e ISAC-S TE recei ves an a ctivat ion sign al ( INFO2), i t resp onds wi th INFO 3 and wai ts
for normal frames (INFO4). This state is reached at most 6 ms after an INFO2 arrives at the
ISAC-S TE (when the oscillator was disabled in "F3 power- down").
F7 Activated
This is the normal active state with the layer-1 protocol activated in both directions. Note that
in IOM-2 mode the 2B+D channels can only be transmitted to the S/T int erface if an "Activation
Reques t" comm and is writt en to the CIX0 regist er. From state "F6 synchro nized", state F7 is
reached at most 0.5 ms after reception of INFO4. From state "F3 power-down" with the
oscillator di sabled, state F7 is reached at most 6 ms afte r the ISAC-S TE is directly activated
by INFO4.
Semicond uctor Group 128
Operational Description
F8 Lost Framing
This is the condition where the ISAC-S TE has lost frame synchronization and is awaiting re-
synchronization by INFO2 or INFO4 or deactivation by INFO0.
Unconditional States
Loop 3 Closed
On Activate Request Loop command, INFO3 is sent by the line transmitter internally to the line
receiver (INFO0 is transmitted to the line). The receiver is not yet synchronized.
Loop 3 Activated
The receiver is synchronized on INFO3 which is looped back internally from the transmitter.
Data may be sent. The indication "TI" or "ATI" is output depending on whether or not a signal
different from INFO0 is detected on the S interface.
Test Mode Continuous Pulses
Continu ous al te rn ati n g puls es are sent.
Test Mode Single Pulses
Single alternating pulses are sent (2-kHz repetition rate).
Reset State
A software rese t (RS) forces the ISAC-S TE to an idle state where the a nalog compon ents are
disabled (transmission of INFO0) and the S line awake detector is inactive. Thus activation
from the NT is not possible. Clocks are still supplied (TE mode) and the outputs ar e in a low
impedance state.
The reset state should be left only with a "Deactivation Indication Upstream" (DIU) command
before any other command is given.
Semicond uctor Group 129
Operational Description
Figure 49a
State Diagram
ITD05429
F3 Power Down
DID DIU
i0i0
i0 i0
TIM
DIS
F3 Power Up
i1 i0
ARUPU
F4 Pend. Act.
F5 Unsynchroniz.
RSYD X
i0i0
F6 Synchronized
ARD X
i2i3
i0 i0
ARUDR
F3 Pend. Deact.F8 Lost Framing
F7 Activated
Uncond. States
X
ix iy
Cmd.Ind.
State
PU
DIU
TIM DIU
i0
ARU
i0
RST TIM
TIM
TIM
X
DIU
i0
i2
ARU
i0
i0
i0 DIU
RSYD X
i0i0
SD
AID ARU
i3 i4
i4
i0
i2
i4
i0
i0
i4
i2
i0
INOUT
S
X:Unconditional Command
can be :ARL,RES,TM,SSP
i0
R
IOM -2
Semicond uctor Group 130
Operational Description
Figure 49b
State Diagram: Unconditional Transitions
ITD02333
PU ARL
*
i3
ix iy
Cmd.Ind.
State
ARL
INOUT
S
X:Forcing Commands
can be :ARL, RES, TM, SSP
i0
ARL
ATI
i3
i3
X
X X
Reset State
EI RS
i0
RS
SCZ
ic
SCZTI
Test Mode
X
SSZ
X
TI
Loop Continuous Puls.
3 Closed
Activated3Loop
1)
i0
i3
1)
*
*
*
Single Pulses
Test Mode
Any SSZ
is
Ind.
1)
:Only Internally
Single Pulses,
:
is Test Pulses,ic:4
96 kHz
kHz
R
IOM
Semicond uctor Group 131
Operational Description
3.3.3 Example of Activation/Deactivation
An example of an activation/deactivation of the S interface, with the time relationships
mentione d in the prev ious chap ters, i s shown in fi gure 50, in the case of a n ISAC®-S TE in TE
and an ISAC- S in LT-S Mo de .
Figure 50
Example of Activation/Deactivation
INFO 0
AR
TE LT-S
INFO 2
AIU
INFO 4
INFO 3
INFO 1
ARD
AID
ARU
RSYD
INFO 0
INFO 0
DIU
DR
DR
ITD05426
32 ms
16 ms 4 ms
16 ms max. 6 ms
max. 2 ms
0.5 ms
-S TEISAC
R
-S / SBCXISAC
R
Semicond uctor Group 132
Operational Description
3.4 Control of Layer-2 Data Transfer
The contr ol of the data t ransfer ph ase is mai nly done b y comman ds from th e µP t o ISAC-S TE
via the Command Register (CMDR).
Table 12 gives a summary of possibl e interrup ts from the HDLC controller an d the appropr iate
reaction to these interrupts.
Table 13 lists the most important comman ds which are issued by a microprocessor by setting
one or several bits in CMDR.
The powerful FIFO logic, which consists of a 2×32 byte r eceive and 2×32 byte transmit FIFO,
as well as an intelligent FIFO controller, build s a flexible interface to the up per protocol layers
implemented in the microcontroller.
The extent of LAPD protocol support is dependent on the selected message transfer mode,
see section 2.3.2.
Table 12
Interrupts from ISAC®-S TE HDLC Controller
MeaningMnemonic Register
(addr. hex) Reaction
Receive Pool Full. Request to
read received bytes of an
uncompleted HDLC frame from
RFIFO
RPF I STA (20) R ea d 3 2 b ytes from RFIFO and
acknowled ge with RMC.
Receive Message End. Request
to read received bytes of a
complete HDLC frame (or the
last part of a frame) from RFIFO.
RME I STA (20) R ea d RFI FO (numb er of bytes
given by RBCL4-0) and status
information and acknowledge
with RMC.
Receive Frame Overflow. A
complete frame has been lost
because stor age space in
RFIFO was not available.
RFO EXIR (24) Error report for statistical
purposes. Possible cause:
deficiency in software.
Protocol Error. S- or I frame with
incorrect N(R) or S frame with
Ifield received (in auto-mode
only) or an Iframe which is not a
comman d or S frame wi th an
undefined control field.
PCE EXIR (24) Link re-establishment.
Indication to layer 3.
Layer-2 Re ceive
Semicond uctor Group 133
Operational Description
Table 12 (cont’d)
MeaningMnemonic Register
(addr. hex) Reaction
Transmit Pool Ready. Further
octets of an HDLC frame can be
written to XFIFO.
If XIFC was issued (auto mode),
indicates tha t th e me ssage wa s
successfully acknowledged with
S frame.
XPR ISTA (20) Write data bytes in the XFIFO if
the frame currentl y being
transmitted is not finish ed or a
new frame is to be transmitted,
and issue an XIF, XIFC, XTF or
XTFC command. In auto mode
applications read the
information in chapter 2.4.5.2.
Transmit Message Repeat.
Frame must be repeated
because of a transmission error
(all HDLC message transfer
modes) or a received negative
acknowledgement (auto mode
only) from peer station.
XMR E XIR (24) Trans missio n of t he fr ame mu st
be repeated. No indication to
layer 3.
Transmit Data Underrun. Frame
has been abor t ed becau s e the
XFIFO holds no further data and
XME (XIFC or XTFC) was not
issued.
XDU EXIR (24) Trans missio n of t he fram e mu st
be repeated. Possible caus e:
excessive software reaction
times.
Receive Status Change .
A status change from peer
station has been received (R R
or RNR frame), auto-mode only.
RSC ISTA (2 0) Stop sending new I frames.
Layer-2 Transm it
Timer Interrupt. External timer
expired or, in auto-mod e,
intern al timer ( T200) and re peat
counter (N200) both
expired.
TIN ISTA (20) Link re-establishment.
Indication to layer 3. (auto-
mode)
Semicond uctor Group 134
Operational Description
Table 13
List of Commands (CMDR (21) Register)
Bit 7…0Command
Mnemonic HEX Meaning
1000 0000RMC 80 Receive Message Complete. Acknowledges a block
(RPF) or a frame (RME) stored in the RFIFO.
0100 0000RRES 40 Reset HDLC Receiver. The RFIFO is cleared. The
transmit and receive counters (V(S), V(R)) are re set
(auto-mode).
0010 0000RNR 20 Receiver Not Ready (auto-mode). An I- or S frame will be
acknowle dged with RNR frame.
0001 0000STI 10 Start Timer.
0000 1010XTFC
(XTF+XME) 0A Transmit Transpare nt Frame and Close. Enabl es the
"transparent" transmission of the block entered last in the
XFIFO. The frame is closed with a CRC and a flag.
0000 0110XIFC
(XIF+XME) 06 Transmit I frame and Close. Enables the "auto-mode"
transmissi on of the b lock en tered last i n the XFIF O. The
frame is closed with a CRC a nd a flag.
0000 1000XTF 08 Transmit Transparent Frame. Enables the "transparent"
transmission of the block entered last in the XFIFO
without closing the frame.
0000 0100XIF 04 Transmit I frame. Enables the " auto-mode" transm ission
of the block entered last in the XFIFO without closing the
frame.
0000 0001XRES 01 Reset HDLC Transmitter. The XFIFO is cleared.
A frame currently in transmission will be aborted and
closed by an abort sequence (7 "1").
Semicond uctor Group 135
Operational Description
3.4.1 HDLC-Frame Reception
Assuming a normally running communication link (layer-1 activated, layer-2 link established,
TEI assigned), figure 51 illustrates the transfer of an Iframe via the D channel. The transmitter
is shown on the left and the receiver on the right, with the interaction between the
microcontroller system and the ISAC-S TE in terms of interrupt and command stimuli.
When the frame (excluding the CRC field) is not longer than 32 bytes, the whole frame is
transfer red i n o ne bl ock. The reception of t he frame is rep or ted vi a t he Receive Me ssag e End
(RME) interrupt. The number of bytes stored in RFIFO can be read out from RBCL. The
Receiv e Status Reg ister ( RSTA) include s info rmat ion a bout the frame, su ch as fram e abo rted
yes/no or CRC valid yes/no and, if complete or partial address recognition is selected, the
identification of the frame address.
Depending on the HDLC-message transfer mode, the address and control field of the frame
can be read from auxi liary regis ters (S APR and RH CR), as shown in figure 52.
Figure 51
Transmission of an I Frame in the D Channel (Subscriber to Exchange)
ITD05677
System
C-µ
(TE)
System
(LT-S)
LAPD Link
XIF/XTF
XPR
XPR
XIF/XTF
XIFC/XTFC
XPR(Transparent
Transmit)
Transmit)
(Auto Mode
XPR
I-Frame
S-Frame
(RR)
)
:= Data Transfer
*
*)In Auto Mode the "RR" Response will be Transmitted Autonomously
RPF
RMC
RPF
RMC
RME
RMC
-
-S TEISAC
R
ISAC
R
-S
C-µ
Semicond uctor Group 136
Operational Description
Figure 52
Receive Data Flow
Note 1 Only if a 2-byte address field is defined (MDS0 = 1 in MODE register).
Note 2 Comparison with Group TEI (FFH) is only made if a 2-byte address field is defined
(MDS0 = 1 in MODE register).
Note 3 In the case of an extended, modulo 128 control field format (MCS = 1 in SAP2
register) the control field is stored in RHCR in comp ressed form (I frames).
Note 4 In the case of an extended control field, only the first byte is stored in RHCR, the
second in RFIFO.
A frame longer than 32 bytes is transferred to the microcontroller in blocks of 32 bytes plus one
remainder block of length 1 to 32 bytes. The reception of a 32-byte block is reported by a
Receive Pool Full (RPF) interrupt and the data in RFIFO remains valid until this interrupt is
acknowledged (RMC). This process is repeated until the reception of the remainder block is
comple ted, as repor ted by RME (figure 51). When the total frame length exceed s 4095 by tes,
bit OV (RBCH ) is set but the counter is not blocked . If the second RFIFO pool ha s been filled
or an end-of-frame is received while a previous RPF or RME interrupt is not yet acknowledged
by RMC, the corresponding interrupt will be generated only when RMC has been issued. When
ITD05674
Description of Symbols:
Checked automatically by ISAC
Compared with Register or Fixed Value
Stored Info Register or RFIFO
Flag High
Address Address
Low Control Information CRC Flag
RSTARHCR
FF
TEI1,TEI2SAP1,SAP2
FE,FC
(Note 1) 2)(Note (Note 3)
RFIFO
RFIFO
FE,FC
SAP1,SAP2 TEI1,TEI2
FF RHCR RSTA
4)(Note (Note 2)1)(Note
RSTA
FF
TEI1,TEI2 RFIFO
RSTA
SAPR
RSTA
RFIFO
RFIFO
SAP1,SAP2
FE,FC
Auto-Mode
(U-and Ι
Non-Auto
Mode
Mode
Transparent
1
2
Transparent
Mode
3
Transparent
Mode
--Frames)
(Note 4)
RHCR
-S TE
R
Semicond uctor Group 137
Operational Description
RME has been indicated, bits 0-4 of the RBCL register represent the number of bytes stored
in the RFIFO. Bits 7-5 of RBCL and bits 0 to 3 of RBCH indicate the total number of 32-byte
blocks which where stored until the reception of the remainder block.
The contents of RBCL, RBCH and RSTA registers are valid only after the occurrence of the
RME interrupt, and remain valid until the microprocessor issues an acknowledgement (RMC).
The contents of RHCR and/or SAPR, also remain valid until acknowledgement.
If a fram e could not b e stored due to a full RFIFO, th e microcontr oller is infor med of this vi a the
Receive Frame Overflow interrupt (RFO).
3.4.2 HDLC-Frame Transmission
After t he XFIFO status has been ch ecked by pol ling the Tran smit FIFO Wr ite Enable (XFW) bit
or after a Transmit Pool Ready (XPR) interrupt, up to 32 bytes may be entered in XFIFO.
Transmissi on of an HDL C frame is sta rted when a tr ansmit comm and (see table 13) is issued.
The opening flag is generate d automatica lly. In the case of an auto-m ode transmissio n (XIF or
XIFC) , the con trol fie ld is al so generat ed by the ISAC- S TE, and the contents o f registe r XAD1
(and, for LAPD, XAD2) are transmitted as the address, as shown in figure 53.
Figure 53
Transmit Data Flow
ITD05667
Flag Address Control Information CRC Flag
FlagCRCXFIFOControlXAD1Flag
HDLC Frame
Flag XAD1 Control XFIFO CRC Flag
FlagCRCXFIFOFlag
XAD2
(XIF)
Transmit I-Frame
Auto Mode,8
16Auto Mode,
Transmit I-Frame
(XIF)
All Modes
Transmit Transparent
Frame (XTF)
Note: Length of Control Field is b or 16
Description of Symbols:
Bit
Bit Addr.
Bit Addr.
Generated automatically by ISAC
Written initially by CPU
Loaded (repeatedly)
(Info Register)
by CPU upon ISAC
(XPR Interrupt)request
-
-
-
R
-S TE
-S TE
R
Semicond uctor Group 138
Operational Description
The HDLC co ntr oller w ill re ques t an other d ata b lock b y an XPR inte rrupt i f ther e a re no mo re
than 32 bytes in XFIFO and the frame close command bit (Transmit Message End XME) has
not been set. To this the microcontroller responds by writing another pool of data and re-
issuing a transmit command for that pool. When XME is set, all remaining bytes in XFIFO are
transmitted, the CRC field and the closing flag of the HDLC frame are appended and the
controlle r generates a new XPR inte rrupt.
The microcontroller does not necessarily have to transfer a frame in blocks of 32 bytes. As a
matter of fact, the sub-blocks issued by the microcontroller and separated by a transmit
command, can be between 0 and 32 bytes long.
If the XFIFO runs out of data and the XME command bit has not been set, the frame will be
terminated with an abort sequence (seven 1’s) followed by inter-frame time fill, and the
microcontroller will be advised by a Transmi t Data Underrun (XDU) interrupt. An HDLC frame
may also be aborted by setting the Transmitter Reset (XRES) command bit.
3.5 Reset
After a hardware reset (pin RST), layer 1 will have reached the following state:
– F3 standby
according to CCITT I.430.
F3 standby state means that the internal oscillator, the DCL clock and FSC1 are active.
During the reset pulse pin SDS1 is "low", all other pins are in high impedance state. The S/T
interface awake detector is active after reset. The F3 power down state, where the internal
oscillator itself is disabled, can be reached by setting the CFS bit (SQXR register) to logical "1".
A subset of ISAC-S TE registers with defined reset values is listed in table 14 .
Table 14
State of ISAC®-S TE Registers after Hardware Reset
Value after
Reset (hex)
Register (address (hex)) Meaning
ISTA (20) 00 No inte rrupts
MASK (20) 00 All interrupts enabled
EXIR (24) 00 No interrupts
STAR (21) 48 (4A) – XFIFO is ready to be written to
– RFIFO is ready to receive at least 16 octets of
a new mess age
CMDR (21) 00 No command
Semicond uctor Group 139
Operational Description
Table 14 (cont’d)
Value after
Reset (hex)
Register (address (hex)) Meaning
MODE (22) 00 – auto-m ode
– 1-octet address field
– external timer mode
– receiver inactive
RBCL (25)
RBCH (2A) 00
XXX000002– no frame bytes received
SPCR (30) 00 – IDP1 pi n = "High"
– Timing mode 0
– IOM interface test loop deactivated
– SDS1 pin = "Low"
CIR0 (31) 7C – no change in S/Q channel
– another device occupies the D and C/I
channels
– received C/I code = "1111"
– no C/I code change
CIX0 (31) 3C – TIC bus is not requested for transmitting a
C/I code
– transmitted C/I code = "1111"
STCR (37) 00 – terminal specific func tions disabled
– TIC-bus address = "0000"
– no synchronous transfer
ADF1 (38) 00 – no test mode
– active clock signals (standby) in TE mode
– no prefilter
– inter- fra m e tim e fil l = cont in uous "1"
ADF2 (39) 00 – IOM-1 interface mode selected
– SDS1 low
SQXR (3B) 0F/00 – S, Q interrupt not enabled
Semicond uctor Group 140
Operational Description
3.6 Initialization
During initialization a subset of registers have to be programmed to set the configuration
parameters according to the application and desired features. They are listed in table 15.
After reset, the ISAC-S TE is in IOM-1 mode. As a result, the fist microcontroller operation has
to be an access to ADF2 to program IOM-2 interface mode.
Table 15
Register (address)
ADF2 (39H)
Bit Effect
IMS
D1C2-0
ODS
Prog ram IOM- 2 interface
mode
Polarity of SDS1
IOM-output driver
tristate/open drain
SPCR (30H)
(Note) SPU
TLP
C2C1-0
C1C1-0
Set the ISAC-S TE in
standby by requesting
clocks
(if CFS = 1, register SQXR)
IOM-interface test loop
B-chan nel switch i ng or
B/IC channel connect
SQXR (3BH)IDC
CFS
IOM-Data Port IDP0,1
direction cont rol (must be
set to "0" for normal
operation)
0 Permanent standby
1 Power-down state
enabled
Application Restricted to
ADF1 (38H)TEM
PFS
IOF
Test Mode
Prefilter enable
IOM OFF/ON
Tests with
layer
1 disabled
TE
IOM-2
CIX0 (31H) RSS Hardware reset generated
by either subscriber/
exchange awake or
watc hdog timer
TE s pecif ic
functions
(TSF = 1)
Semicond uctor Group 141
Operational Description
Table 15 (cont’d)
Note: After a hardware reset the pin SDS1 is "low", until the SPCR is written to for the first
time. From that moment on, the function taken on by these pins depends on the state
of the IOM Mode Select bit IMS (ADF2 register).
SAP1/2 (26H/27H)
TEI1/2 (28H/29H)
Register (address) Bit Effect Application Restricted to
STCR (37H)TSF
TBA2-0
Terminal specific function
enable
TIC-bus address Bus
configuration
for D + C/I
(TIC)
MODE (22H)MDS2-0
TMD
DIM2-0
HDLC-m essage trans fer
mode 2 bytes/1 byte address
Timer mode
external/internal
Point-to-point/TIC-bus
conf iguration on IOM
interface, for D + C/I channel
arbitration
Point-to-point/bus
conf iguration on S/T
interface, for D-channel
access.
Auto-mode
only
TIMR (23H) CNT
VALUE N1 and T1 in internal timer
mode (TMD = 1)
T2 in external timer mode
XAD1 (24H)
XAD2 (25H)SA PI, TEI
Transmit frame address Auto-mode
only
Receive SAP I, TEI address
values for in terna l address
recognition
Semicond uctor Group 142
Register Description
4 D etailed Register Description
The parameterization of the ISAC-S TE and the transfer of data and control information
between the µP and ISAC-S TE is performed through two register sets.
The register set in the address range 00-2BH pertains to the HDLC transceiver and LAPD
controller. It includes the two FIFOs having an identical address range from 00-1FH.
The register set ranging from 30-3BH pertains to the control of layer-1 functions and of the IOM
interface.
The address map and a register summary are shown in the following tables:
Table 16
ISAC®-S TE Address Map 00-2BH
Name Description
ReadAddress
(hex)
Name Description
Write
RFIFO Receive FIFO
00
.
.
1F
XFIFO Transmit FIFO
ISTA Interrupt Status Register20 MASK Mask Register
STAR Status Register21 CMDR Command Register
MODE Mode Register22 TIMR Timer Register23 EXIR Extended Interrupt
Register
24 XAD1 Transmit Address 1
RBCL Receive Frame Byte C ount
Low
25 XAD2 Transmit Address 2
SAPR Received SAPI26 SAP1 Individual SAPI 1
RSTA Receive Status Register27 SAP2 Individual SAPI 2
28 TEI1 Individual TEI 1
RHCR Rece ive HDLC Control29 TEI2 Individual TEI 2
RBCH Receive Frame Byte C ount
High
2A
STAR2 Status Register 22B
Semicond uctor Group 143
Register Description
Table 17
ISAC®-S TE Address Map 30-3BH
Name Description
ReadAddress
(hex)
Name Description
Write
SPCR Serial Port Contro l Register30 CIR0 Command/Indication
Receive 0
31 CIX0 Command/Indication
Transmit 0
MOR1 MONITOR Receive 134 MOX1 MONITOR Transmit 1
C1R Channel Register 135
MOR0 MONITOR Receive 032 MOX0 MONITOR Transmit 0
CIR1 Command/Indication
Receive 1
33 CIX1 Command/Indication
Transmit 1
C2R Channel Register 236
B1CR B1-Channel Register37 STCR Sync Transfer Control
Register
B2CR B2-Channel Register38 ADF1 Additional Feature Register 1
ADF2 Additional Feature Register 239 MOSR MONITOR St atus Reg i ster3A MOCR MONITOR Control Register
SQRR S-, Q-Channel Receive
Register
3B SQXR S-, Q-Channel Transmit
Register
Semicond uctor Group 144
Register Description
Table 18
Register Summary: HDLC Operation and Status Registers
EXISINCISQTINXPRRSCRPFRME20H
07 ISTA R
EXISINCISQTINXPRRSCRPFRME20HMASK W
MAC0XMAC1MBRRRNRXRNRXFWXDOV21HSTAR R
XRESXMEXIFXTFSTIRNRRRESRMC21HCMDR W
DIM0DIM1DIM2RACTMDMDS0MDS1MDS222HMODE R/
W
WOVSAWMOSSOVRFOPCEXDUXMR24HEXIR R
TAC/RSA0SA1RABCRCRDORDA27HRSTA R
00MULT000002BHSTAR2 W
VALUE23HTIMR R/
W
24HXAD1 W
RBC0RBC1RBC2RBC3RBC4RBC5RBC6RBC725HRBCL R
25HXAD2 W
29HRHCR R
RBC8RBC9RBC1RBC1OVVN0VN1XAC2AHRBCH R
26HSAPR R
0CRI
SAPI1
26HSAP1 W
0MCS27HSAP2 W
EA28HTEI1 W
29HTEI2 W
SDETTRECMULTWFA00002BHSTAR2 R
CNT
SAPI2
TEI1
EA
TEI2
Semicond uctor Group 145
Register Description
Table 19
Register Summary: Special Purpose Register IOM®-2 Mode
IOM®-2:
C2C0C2C1C1C0C1C1TLP00SPU30H
07 SPCR R/
W
37HB1CR R
CIC1CIC0BASSQC31HCIR0 R
11BACRSS31HCIX0 W
32HMOR0 R
32HMOX0 W
MAB0MDA0MER0MDR0MAB1MDA1MER1MDR13AHMOSR R
MXC0MXE0MRC0MRE0MXC1MXE1MRC1MRE13AHMOCR W
35HC1R R/
W
36HC2R R/
W
SC0SC1ST0ST1TBA0TBA1TBA2TSF37HSTCR W
38HB2CR R
D1C0D1C1D1C2ODS000IMS39HADF2 R/
W
SQR4SQR3SQR2SQR1SYNCI1ECFSIDC3BHSQRR R
SQX4SQX3SQX2SQX1SQIECI1ECFSIDC3BHSQXR W
MX1MR133HCIR1 R
1133HCIX1 W
34HMOR1 R
34HMOX1 W
ITF00IOFPFSTEMWTC2WTC138HADF1 W
CODR0
CODX0
CODR1
CODX1
Semicond uctor Group 146
Register Description
4.1 HDLC Operation and Status Registers
4.1.1 Receive FIFO RFIFO Read Address 00-1FH
A read access to any address within the range 00-1FH gives access to the "current" FIFO
location selected by an internal pointer which is automatically incremented after each read
access. This allows for the use of efficient ’move string’ type commands by the processor.
The RFIFO contains up to 32 bytes of received frame.
After an ISTA:RPF interrupt, exactly 32 bytes are available.
After an ISTA:RME interrupt, the number of bytes available can be obtained by reading the
RBCL register.
4.1.2 Transmit FIFO XFIFO Write Address 00-1FH
A write access to any address within the range 00-1FH gives access to the "current" FIFO
location selected by an internal pointer which is automatically incremented after each write
access. This allows for the use of efficient ’move string’ type commands by the processor.
Up to 32 bytes of transmit data can be written into the XFIFO following an ISTA:XPR interrupt.
4.1.3 Interrupt Status Register ISTA Read Address 20H
Value aft er reset: 00H
RME Receive Message End
One complete frame of length less than or equal to 32 bytes, or the last part of a frame
of length great er than 32 bytes has been receiv ed. Th e contents are available in the
RFIFO. The message length and additional information may be obtained from
RBCH + RBCL and the RSTA register.
RPF Receive Pool Full
A 32-byte block of a frame longer than 32 bytes has been received and is available
in the RFIFO. The frame is not yet complete.
RSC Receive Status Change. Used in auto-mode o nly .
A status change in the receiver of the remote station – Receiver Ready/Receiver Not
Ready – has been detected (RR or RNR S frame).
The actual status of the re mote station can be read from the STAR register (RRNR
bit).
EXISINCISQTINXPRRSCRPFRME 07
Semicond uctor Group 147
Register Description
XPR Transmit Pool Ready
A data block of up to 32 bytes can be written to the XFIFO.
An XPR interrupt will b e g en erated in the follo wing cases:
– afte r an XTF o r XIF comm and, wh en one t ransmit poo l is emp tied an d the fr ame is
not yet complete
– after an XTF together with an XME command is issued, when the whole
transparent frame has been transmitted
– after an XIF together with an XME command is issued, when the whole Iframe has
been transmitted and a positive acknowledgement from the remote station has
been re ceived, (auto-mode).
TIN Timer Interrupt
The internal timer an d re peat counter has e x pired (see TIMR register).
CISQ C/I- or S/Q-Channel Change
A change in C/I channel 0, C/I channel 1 (only in IOM-2 TE mod e) or S/Q channe l has
been recognized. The actual value can be read from CIR0, CIR1 or SQRR.
SIN Synchronous Transfer Interrupt
When programmed (STCR register), this interrupt is generated to enable the
processor to lock on to the IOM timing, for synchronous transfers.
EXI Extended Interrupt
This bi t indicates that one of six n on-critical i nterrupts ha s been gene rated. The e xact
interrupt cause can be read from E XIR.
Note: A read of the ISTA register clears all bits except EXI and CISQ. EXI is cleared by
reading the EXIR register, CISQ is cle are d by reading CIRR/CIR0.
4.1.4 Mask Register MASK Write Address 20H
Value aft er reset: 00H
Each interrupt source in the ISTA reg ister can be selectively maske d by setting t o "1"
the corresponding bit in MASK. Masked interrupt status bits are not indicated when
ISTA is r ead. Inste ad, the y remain interna lly sto red and pe ndin g, until the mask bit is
reset to zero.
Note: In the event of an extended interrupt and of a C/I- or S/Q-channel change, EXI and
CISQ ar e se t in ISTA ev en if the corresp ondi ng mask bits in M ASK are active, b ut no
interrupt (I NT pin) is generated.
07 EXISINCISQTINXPRRSCRPFRME
Semicond uctor Group 148
Register Description
4.1.5 Status Register STAR Read Addres s 21H
Value aft er reset: 48H or 4A H
XDOV Transmit Data Overflow
More than 32 bytes have been written in one pool of the XFIFO, i.e. data has been
overwritten.
XFW Transmit FIFO Write Enable
Data can be written in the XFIFO. This bit may b e polled inste ad of (or in a dditio n to )
using the XPR interrupt.
XRNR Transmit RNR. Used in auto-m ode only
In auto-mode, this bit indicates whether the ISAC-S TE receiver is in the "ready" (0)
or "not ready" (1) state. When "not ready", the ISAC-S TE sends an RNR S frame
autonomously to the remote station when an Iframe or an S frame is received.
RRNR Receive RNR. Used in auto-mode only
In the aut o-mode , this bit i ndicates wheth er the IS AC-S TE has r eceived an RR or an
RNR frame, this being an indication of the current state of the remote station: receiver
ready (0 ) or receiver not ready (1).
MBR Message Buffer Ready
This bi t sign ifies th at tem porar y stor age i s availa ble in t he RFIFO to rec eive at l east
the first 16 bytes of a new message.
MAC1 MONITOR Transmit Channel 1 Active (IOM-2 termina l mode only)
Data transmissi on is in progress in MONITOR ch annel 1.
MAC0 MONITOR Transmit Channel 0 Active. Used in IOM-2 mode only.
Data transmissi on is in progress in MONITOR ch annel 0.
Note: Bit 1 may toggle dependend the time of access.
07 MAC0XMAC1MBRRRNRXRNRXFWXDOV
Semicond uctor Group 149
Register Description
4.1.6 Command Register CMDR Write Address 21 H
Value aft er reset: 00H
Note: The maximum time between writing to the CMDR register and the execution of the
command is 2.5 DCL-clock cycles. Du ring this time n o further comma nds should b e
written to the CMDR register to avoid any loss of commands.
RMC Receive Message Complete
Reaction to RPF (Receive Pool Full) or RME (Receive Message End) interrupt. By
setting this b i t, th e processor confirms tha t it h as f etch ed the da ta , and indicates th at
the corresponding space in the RFIFO may be released.
RRES Receiv er Re set
HDLC receiver is reset, the RFIFO is cleared of any data.
In addition, in auto-mode, the transmit and receive counters (V(S ), V(R)) are reset
RNR Receiver N ot Ready
Used in auto-mode only.
Determines the state of the ISAC-S TE HDLC receiver.
When RNR = "0", a received I or S-frame is acknowledged by an RR supervisory
frame, otherwise by an RNR supervisory frame.
STI Start Timer
The ISAC-S TE hardware timer is started wh en STI is set to o ne. In t he inte rnal timer
mode (TMD bit, MODE register) an S command (RR, RNR) with poll bit set is
transmitted in addition. The timer may be stopped by a write of the TIMR register.
XTF Transmit Transparent Frame
After having written up to 32 bytes in the XFIFO, the processor initiates the
transmission of a transparent frame by setting this bit to "1". The opening flag is
automatically added to the message by the ISAC-S TE.
XIF Transmit I Frame
Used in auto-mode only
After having written up to 32 bytes in the XFIFO, the processor initiates the
transmission of an I fra me by setting thi s bit to " 1". The openi ng flag, the addr ess and
the control field are automatically added by the ISAC-S TE.
07
XRESXMEXIFXTFSTIRNRRRESRMC
Semicond uctor Group 150
Register Description
XME Transmit Message End
By setting this bit to "1" the processor indicates that the data block written last in the
XFIFO completes the corresponding frame. The ISAC-S TE terminates the
transmission by appending the CRC and the closing flag sequence to the data.
XRES Transmitter Reset
HDLC transmitter is reset and the XFIFO is cleared of any data.
This command can be used by the processor to abort a frame currently in
transmission.
Notes: ●After an XPR interrupt further data has to be written in the XFIFO and the
appropriate Transmit Command (XTF or XIF) has to be written in the CMDR
register again to continue transmission, when the current frame is not yet complete
(see also XPR in ISTA).
●During frame transmission, the 0-bit insertion according to the HDLC bit-stuffing
mec han i sm is don e automatica l ly.
4.1.7 Mode Register MODE Read/Write Address 22H
Value aft er reset: 00H
MDS2-0 Mode Select
Determine s the message transfer mode of the HDLC controller, as follows:
07 DIM0DIM1DIM2RACTMDMDS0MDS1MDS2
Semicond uctor Group 151
Register Description
Note: SAP1, SAP2: two programmable address values for the first received address byte
(in the case of an address field longer than 1 byte); SAPG = fixed value FC/FEH.
TEI1, TEI2: two programmable address values for the second (or the only, in the case
of a one-byte address) received address byte; TEIG = fixed value FFH.
TMD Timer Mode
Sets t he oper ating mode of the IS AC-S TE t imer. In t he exte rnal mode (0 ) the tim er
is controlled by the processor. It is started by setting the STI bit in CMDR and it is
stopped by a write of the TIMR register.
In the internal mode (1) the timer is used internally by ISAC-S TE for timeout and retry
conditions (handling of LAPD/HDLC protocol in auto-mode).
RAC Receiver Active
The HDLC receiver is activated when this bit is set to "1".
DIM2-0 Digital Interface Mode
These bits define the characteristics of the IOM-Data Ports (IDP0, IDP1) according to
following tables:
MDS2
MDS1
MDS0
Address Comparison
1. Byte 2. Byte Remark
0 0 0 TEI1, TEI2 –One-byte address
compare. HDLC-protocol
handling for frames with
address TEI1
Mode
Auto-mode
Number
of
Address
Bytes
1
0 0 1 SAP1, SAP2, SAPG TEI1, TEI2, TEIG Two-byte address
compare. LAPD-protocol
handling for frames with
address SAP1 + TEI1
Auto-mode 2
0 1 0 TEI1, TEI2 – One-byte ad dr ess
compare.
Non-auto
mode 1
0 1 1 SAP1, SAP2, SAPG TEI1, TEI2, TEIG Two-byte address
compare.
Non-auto
mode 2
1 0 0 Reserved
1 0 1 – TEI1, TEI2, TEIG Low-byte address
compare.
Transparent
mode 1 >1
1 1 0 – – No address compare.
All frames accepted.
Transparent
mode 2 –
1 1 1 SAP1, SAP2, SAPG –Hi gh-byte addr ess
compare.
Transparen t
mode 3 >1
Semicond uctor Group 152
Register Description
IOM®-2 Modes (ADF2:IMS = 1)
4.1.8 Timer Register TIMR Read/Write Address 23H
Value after reset: undefined (previous value)
CNT The meaning depends on the selected timer mode (TMD bit, MODE register).
* internal Timer Mode (TMD = 1)
CNT indicates the maximum number of S commands "N1" which are transmitted
autonomously by the ISAC-S TE after expiration of time period T1 (retry, according
to HDLC).
Characteristics
IOM-2 terminal mode
SPCR:SPM = 0 ××
100-111
Last octet of IOM channel 2
used for TIC-bus access ×
Stop/go bit evaluated for
D-channel access handling ××
Reserved
Applications
TE mode
001 011
×
××
DIM2-0
×
010
×
×
000
07
VALUECNT
Semicond uctor Group 153
Register Description
The internal timer procedure will be started in auto-mode:
– after start of an I-frame transmission
or
– after an "RNR" S fr ame has been receive d.
After the last retry, a timer interrupt (TIN bit in ISTA) is generated.
The timer procedure will be stopped when
– a TIN interrupt is generated. The time between the start of an I-frame
transmission or reception of an "RNR" S frame and the generation of a TIN
interrupt is equal to: (CNT+1)×T1.
– or the TIMR is written
– or a positive or negative acknowledgement has been received.
Note: The maximum value of CNT can be 6. If CNT is set to 7, the number of retries
is unlimit ed.
* External Timer Mode (TMD = 0)
CNT together with VALUE determine the time period T2 after which a TIN interrupt
will be gen er at ed:
CNT × 2.048 s + T1
with T1 = (VALUE + 1) × 0.064 s,
in the normal case, and
T2 = 16348 × CNT × DCL + T1
with T1 = 512 × (VALUE + 1) × DCL
when TLP = 1 (test loop activated, SPCR register).
DCL denotes t he perio d of the DCL clock.
The timer can b e started by se tting the STI bit in C MDR a nd will be stoppe d when a
TIN interrupt is generated or the TIMR register is written.
Note: If CNT is set to 7, a TIN interrupt is indefinitely generated after every
expiration of T1.
VALUE Determines the Time Period T1:
T1 = (VA LU E + 1) × 0.064 s (SPCR:TLP = 0, normal mod e)
T1 = 512 × (VALUE + 1) × DCL (SPCR:TLP = 1, test mode).
Semicond uctor Group 154
Register Description
4.1.9 Extended Interrupt Register EXIR Read Address 24H
Value aft er reset: 00H
XMR Transmit Message Repeat
The transmission of the last frame has to be repeated because:
– the ISAC-S TE has received a negative acknowledgement to an Ifram e in auto-
mode (according to HDLC/LAPD)
– or a collision on the S bus has been detected after the 32nd data byte of a tran smit
frame.
XDU Transmit Data Underrun
The current transmission of a frame is aborted by transmitting seven "1's" because
the XFIFO holds no further data. This interrupt occurs whenever the processor has
failed to respond to an XPR interrupt (ISTA register) quickly enough, after having
initiated a transmission and the message to be transmitted is not yet complete.
Note: When an XMR or and XDU interrupt is generated, it is not possible to send
transpa rent fram es or Ifram es u nti l the int er rupt ha s been ackno w le dg ed by reading
EXIR.
PCE Protocol Error
Used in auto-mode only.
A protocol error has been detected in auto-mode due to a received
–S- or Iframe with an incorrect sequence number N(R) or
– S frame containing an Ifield.
–Iframe which is not a command.
– S frame with an undefined control field.
RFO Receive Frame Overflow
The received data of a frame could not be stored, because the RFIFO is occupied.
The whole message is lost .
This interrupt can be used for statistical purposes and indicates that the processor
does not respond quickly enough to an RPF or RME interrupt (ISTA).
SOV Synchronous Transfer Overflow
The synchronous transfer programmed in STCR has not been acknowledged in time
via the SC0/SC1 bit.
MOS MONITOR Status
A change in the MONITOR Status Register (MOSR) has occured.
07 WOVSAWMOSSOVRFOPCEXDUXMR
Semicond uctor Group 155
Register Description
SAW Subscriber Awake
Used only if terminal specific functions are enabled (STCR:TSF = 1).
Indicat es that a f allin g edge on the EAW lin e has be en dete cted, in ca se the te rmina l
specific functions are enabled (TSF bit in STCR).
WOV Watchdog Timer Overflow
Used only if terminal specific functions are enabled (STCR:TSF = 1).
Signals the expiration of the watchdog timer, which means that the processor has
failed to set the watchdog timer control bits WTC1 and WTC2 (ADF1 register) in the
correct man ner. A re set pulse has been ge nerated by the ISAC-S TE.
4.1.10 Transmit Address 1 XAD1 Write Address 24H
Used in auto-mode only.
XAD1 contains a programmable ad dress byte which is appen ded automatically to the
frame by the ISAC-S TE in auto-mode. Depending on the selected address mode
XAD1 is interpreted as follows:
* 2-Byte Address Field
XAD1 is the high byte (SAPI in the ISDN) of the 2-byte address field. Bit 1 is
interpreted as the command/response bit "C/R". It is automatically generated by the
ISAC-S TE following the rules of ISDN LAPD protocol and the CRI bit value in SAP1
register. Bit 1 has to be set to "0".
In the ISDN LAPD the address field extension bit "EA", i.e. bit 0 of XAD1 has to be
set to "0".
* 1-Byte Address Field
According to the X.25 LAPB protocol, XAD1 is the addre ss of a command frame.
Note: In standard ISDN applications only 2-byte address fields are used.
C/R Bit
Command Response Transmitting End CRI Bit
01subscriber0
1 0 network 1
07
Semicond uctor Group 156
Register Description
4.1.11 Receive Frame Byte Count Low RBCL Read Address 25H
Value aft er reset: 00H
RBC7-0 Receive Byte Count
Eight least significant bits of the total number of bytes in a received message. Bits
RBC4-0 indicate the length of the data block currently available in the RFIFO, the
other bits (together with RBCH) indicate the number of whole 32-byte blocks
received.
If exactly 32 byte s are re ceived RBCL holds the value 20H.
4.1.12 Transmit Address 2 XAD2 Write Address 25H
Used in auto-mode only.
XAD2 cont ains th e second pr ogram mable addre ss byte, whos e function depen ds on
the selected addr ess mode:
* 2-Byte Address Field
XAD2 is the low byte (TEI in the ISDN) of the 2-byte address field.
* 1-Byte Address Field
According to the X.25 LAPB protocol, XAD2 is the address of a response frame.
Note: See note to XAD1 register description.
4.1.1 3 Re ceived SAPI Re gist e r SAP R Read Address 26 H
When transparent mode 1 is selected, SAPR contains the value of the first address
byte of a receive frame.
07 RBC0RBC1RBC2RBC3RBC4RBC5RBC6RBC7
07
07
Semicond uctor Group 157
Register Description
4.1. 14 SAPI 1 Register SAP1 Write Address 26H
SAPI 1 SAPI1 Value
Value of the first programmable Service Access Point Identifier (SAPI) according to
the ISDN LAPD protocol.
CRI Command/Response Interpretation
CRI defines the end of the ISDN user-network interface the ISAC-S TE is used on,
for the correct identification of "Command" and "Response" frames. Depending on
the value of CRI the C/R bit will be interpreted by the ISAC-S, when receiving frames
in auto-mode, as follows:
For transmitting frames in auto-mode, the C/R-bit manipulation will also be done
automatically, depending on the value of the CRI bit (refer to XAD1-register
description).
In messag e tr an sfer m od es wi th S API a dd re ss r ecog niti o n th e fi rs t r eceived address
byte is compared with the programmable values in SAP1, SAP2 and the fixed group
SAPI.
In 1-byte address mode, the CRI bit is to be set to "0".
4.1.15 Receive Status Register RSTA Read Address 27H
Value after reset: undefined
RDA Receive Data
A "1" indicates that data is available in the RFIFO. After an RME interrupt, a "0" in this
bit means that data is available in the internal registers RHCR or SAPR only (e.g.
S frame). See also RHCR-register description table.
RDO Receive Data Overflow
At least on e byte of the fra me has been lo st, because i t could not be stor ed in RFIFO
(1).
C/R B i t
CRI Bit Receiving End Command Response
0 subscriber 1 0
1network01
07 0CRISAPI1
07 TAC/RSA0SA1RABCRCRDORDA
Semicond uctor Group 158
Register Description
CRC CRC Check
The CRC is correct (1) or incorrect (0).
RAB Receive Message Aborted
The receive message was aborted by the remote station (1), i.e. a sequence of 7 1’s
was detected.
SA1-0 SAPI Address Identification
TA TE I Address Identification
SA1-0 ar e significant in aut o-mode and non-au to mode with a two-b yte address field,
as well as in transparent mode 3. TA is significant in all modes except in transparent
modes 2 and 3.
Two programmable SAPI values (SAP1, SAP2) plus a fixed group SAPI (SAPG of
value FC/FEH), and two programmable TEI values (TEI1, TEI2) plus a fixed group
TEI (TEIG of value FFH), are availabl e for address comparison.
The result of the address comparison is given by SA1-0 and TA, as follows
Notes: ●If the SAPI values programmed to SAP1 and SAP2 are identical the reception of a
fram e with SAP2/TEI2 results in the indication SA1 = 1, SA0 = 0, TA = 1.
●Normal ly RSTA sho uld be read by th e processor after an RME int errupt in order to
determine the status of the received frame. The contents of RSTA are valid only
after an RME interrupt, and remain so until the frame is acknowledged via the RMC
bit.
SA1 SA0 TA 1st Byte 2nd Byte
Address Match with
x
x
Number of address
bytes = 1 x
x0
1TEI2
TEI1 –
–
0
0
0
0
1
1
1
Number of address
bytes = 2
0
0
1
1
0
0
1
0
1
0
1
0
1
x
SAP2
SAP2
SAPG
SAPG
SAP1
SAP1 reserved
TEIG
TEI2
TEIG
TEI1 or TEI2
TEIG
TEI1
Semicond uctor Group 159
Register Description
C/R Command/Response
The C/R bit identifies a receive frame as either a command or a response, according
to the LAPD rules:
4.1. 16 SAPI 2 Register SAP2 Write Address 27H
SAPI 2 SAPI2 Value
Value o f th e se cond pr og r am mabl e Ser vi ce A ccess Point Ide ntifi er (SAPI) accord ing
to the ISDN LAPD protocol.
MCS Modulo Count Select
Used in auto-mode only.
This bit determin es the HDLC-control field format as follo ws:
0: One-byte control field (modulo 8)
1: Two-byte control field (modulo 128)
4.1.17 TEI1 Register 1 TEI1 Write Address 28H
EA Address Field Extension Bit
This bit has to be set "1" according to HDLC/LAPD.
In all me ssage tran sfer m odes except i n transpa rent mode s 2 and 3, TEI1 is use d by
the ISAC-S for address recognition. In the case of a two-byte address field, it contains
the value of the first programmable Terminal Endpoint Identifier according to the
ISDN LAPD protocol.
In the auto-mode with a two-byte address field, numbered frames with the address
SAPI1-TEI1 are handled autonomously by the ISAC-S TE according to the LAPD
protocol.
Command Response Direction
0 1 Subscriber to network
1 0 Network to subscriber
07
0MCSSAPI2
07
EATEI1
Semicond uctor Group 160
Register Description
SAPI1
Note: If the value FFH is programmed in TEI1, received numbered frames with address
SAPI1-TEI1 (SAPI1-TEIG) are not handled autonomously by the ISAC-S TE.
In auto and non-auto-modes with one-byte address field, TEI1 is a command
address, according to X.25 LAPB.
4.1.18 Receive HDLC Control Register RHCR Read Address 29H
In all modes except transparent modes 2 and 3, this register contains the control field of a
received HDLC frame. In transparent modes 2 and 3, the register is not used.
07
Mode Modulo 8
(MCS = 0) Modulo 128
(MCS = 1) Contents of RFIFO
Auto-mode,
1-byte address
(U/I frames)(Not e 1)
Cont rol field U- frames only:
Cont rol field (Note 2)
Fro m 3rd byte after flag
(Note 4)
Auto-mode,
1-byte address
(I fram es)
Cont rol field in
compre ssed form
(Note 3)
Fro m 4th byte after flag
(Note 4)
Auto-mode,
2-byte address
(U/I frames)(Not e 1)
Cont rol field U- frames only:
Cont rol field (Note 2)
Fro m 4th byte after flag
(Note 4)
Auto-mode,
2-byte address
(I fram es)
Cont rol field in
compre ssed form
(Note 3)
Fro m 5th byte after flag
(Note 4)
Non-auto mode,
1-byte address 2nd byte after flag Fro m 3 rd byte after flag
Non-auto mode,
2-byte address 3rd byte after flag Fro m 4th byte after flag
Transparent mode 1 3rd byte after flag Fro m 4th byte after flag
Transparent mode 2 –Fro m 1st byte after flag
Transparent mode 3 – Fro m 2nd byte after flag
Contents of RHCR
Semicond uctor Group 161
Register Description
Note 1: S frames are handled automatically and are not transferred to the microprocessor.
Note 2: For U frames (bit 0 of RHCR = 1) the control field is as in the modulo 8 case.
Note 3: For I frames (bit 0 of R HCR = 0) the compressed con trol field has the same format
as in the modulo 8 case, but only the three LSB’ s of the receive and transmit counters
are visible:
Note 4: I field.
4.1.19 TEI2 Register TEI2 Write Address 29H
EA Address Field Extension Bit
This bit is to be set to "1" according to HDLC/LAPD.
In all message transfer modes except in transparent modes 2 and 3, TEI2 is used by the
ISAC-S TE for address recognition. In the case of a two-byte address field, it contains the
value of the second programmable Terminal Endpoint Identifier according of the ISDN LAPD
protocol.
In auto and non-auto modes with one-byte address field, TEI2 is a response address,
according to X.25 LAPB.
4.1.20 Receive Frame Byte Count High RBCH Re ad Address 2AH
Value aft er reset: 0XX0 000 02.
XAC Transmitter Active
The HDLC transmitter is active when XAC = 1. This bit may be polled. The XAC bit is
active when
– either an XTF/XIF command is issued and the frame has not been completely
transmitted
– or the transmission of an S frame is internally initiated and not yet completed.
VN1-0 Version Nu mber of Chip
00 ... V1.1 version
0PN(R)2-0 N(S)2-0 07
07 EA
TEI2
07 RBC8RBC9RBC10RBC11OVVN0VN1XAC
Semicond uctor Group 162
Register Description
OV Overflow
A "1" in this bit position indicates a message longer than 4095 bytes.
RBC8-11Receive Byt e Count
Four m ost significant bits of the total number of bytes in a received message .
Note: Normally RBCH an d RBCL should be rea d by the proce ssor after an RME in terrupt
in order to determine the number of bytes to be read from the RFIFO, and the total
message length. The contents of the registers are valid only after an RME interrupt,
and remain so until the frame is acknowledged via the RMC bit.
4.1.21 Status Register 2 STAR2 Read/Write A ddress 2BH
Value aft er reset: 00H
a) WRITE
MULT Used to enable or disable the multiframe structure (see chapter 2.4.9)
1: S/T multiframe disabled
0: S/T multiframe enabled
b) READ
WFA Waiting for Acknowledge
This bit shows, if the last transmitted Iframe was ack nowled ged, i.e. V(A) = V(S)
(⇒ WFA = 0) or was not yet acknowledged, i.e. V(A) < V(S) (⇒ WFA = 1).
MULT The value written into the register bit is read.
TREC Timer Recovery Status:
0: The device is not in the timer recovery state.
1: The device is in the timer recovery state.
SDET S Frame Detected:
This bit is set to "1" by the first received correct Iframe or S command with p = 1.
It is reset by reading STAR2.
07 00MULT00000
07 SDETTRECMULTWFA0000
Semicond uctor Group 163
Register Description
4.2 Speci al Purpose Register s: IOM®-2 Mode
The following register de scription is only valid if IOM-2 is selected (ADF2:IM S-1).
4.2.1 Serial Port Control Register SPCR Read/Write Address 30H
Value aft er reset: 00H
Important Note After a hardware rese t the pin SDS1 is "low" un til the SPCR is written to for
the first time . From that moment on, the fu nction taken on by these pins de-
pends on the state of the IOM Mode Select bit IMS (ADF2 register).
SPU Software Power-Up.
Used in TE mode on ly.
If SQXR:CFS = 1, before activating the ISDN S interface in TE mode the SPU and
SQXR:IDC bits have to be set to "1" and then cleared again:
After a subsequent CISQ interrupt (C/I code change; ISTA) and reception of the C/I
code "PU " (Pow er-U p indica tion i n TE mode) th e rea ction of the p rocessor w ould b e:
– to write an activate request command as C/I code in the CIX0 register.
– to reset the SPU and SQXR:IDC bits and wait for the following CISQ interrupt.
TLP Test Loop
When set to 1 the IDP1 and IDP0 lines are internally connected together,
and the times T1 and T2 are reduced (cf. TIMR).
C1C1, C1C0 Channel 1 Connect
Determines which of the two channels B1 or IC1 is connected to register
C1R and/or B1CR, for monitoring, test-looping and switching data
to/from the processor.
C2C0C2C1C1C0C1C1TLP00SPU 07
C1C1 Application(s)C1C0 Read Write Read
0B1 monitoring + IC1 monitoring0 IC1 – B1
0B1 monitoring + IC1 looping from/to IOM1 IC1 IC1 B1
1B1 access from/to S0; transmission of
a constant value in B1 channel to S0.
0 – B1 B1
1B1 looping from S0; transmission of
a variable pattern in B1 channel to S0.
1B1 B1 –
C1R B1CR
Semicond uctor Group 164
Register Description
C2C1, C2C0 Channel 2 Connect
Determines which of the two channels B2 or IC2 is connected to register
C2R an d/or B2 CR, for monitoring, test-looping and swit ching data
to/from the processor.
4.2.2 Command/Indication Receive 0 CIR0 Read Address 31H
Value aft er reset: 7CH
SQC S/Q Channel Change
A change i n the receiv ed 4-b it S- channe l (TE or LT-T mo de) h as bee n detect ed. The
new code can be read from the SQRR. This bit is reset by a read of the SQRR.
BAS Bus Access Status
Indicates the state of the TIC bus:
0: the ISAC-S TE itself occupies the D and C/I channel
1: another device occupies the D and C/I channel
CODR0 C/I Code 0 Receive
Value of the received Command/Indication co de. A C/I code is loaded in CODR0 only
after being the same in two consecutiv e IOM frames and th e previou s code h as been
read from CIR0.
(refer to chapter 3.3.2)
CIC0 C/I Code 0 Change
A change i n the r ece i ved C om mand /Indication code has bee n re cognized. Th is bit is
set only w hen a new cod e is dete cted in two consecut iv e IOM fram es. It is re set by a
read of CIR0.
C2C1 Application(s)C2C0 Read Write Read
0B2 monitoring + IC2 monitoring0 IC2 –B2
0B2 monitoring + IC2 looping from/to IOM1 IC2 IC2 B2
1B2 access from/to S0; transmission of
a constant value in B2 channel to S0.
0 – B2 B2
1B2 looping from S0; transmission of
a variable pattern in B2 channel to S0.
1B2 B2 –
C2R B2CR
CIC1CIC0BASSQC 07
CODR0
Semicond uctor Group 165
Register Description
CIC1 C/I Code 1 Change
A chan ge in the receive d Command /Indi cation c ode in IOM channel 1 has been rec-
ognized. This bit is set when a new code is detected in one IOM frame. It is reset by
a read of CIR 0.
CIC1 is only used if term inal mode is selected.
Note: The BAS and CODR0 bits are updated every time a new C/I code is detected in two
consecutive IOM frames.
If several consecutive valid new codes are detected and CIR0 is not read, only the
first and th e last C/ I code (and B AS bit) is ma de availab le in CIR0 at the first and sec-
ond read of that register, respectively.
4.2.3 Command/Indication Transmit 0 CIX0 Write Address 31H
Value aft er reset: 3FH
RSS Reset Source Select
Only valid if the terminal specific functions are activated (STCR:TSF).
0: Subscribe r or Exchan ge Awake
As reset source serves:
– a falling edge on the EAW line (External Subscriber Awake)
– a C/I code change (E xchange Awake) .
A logical zero on the EAW line activates also the IOM-interface clock and frame
signal, just as the SPU-bit (SPCR) does.
1: Watchdog Timer
The expiration of the watchdog timer generates a reset pulse.
The watchdog timer will be reset and restarted, when two specific bit
combinations are written in the ADF1 register within the time period of 128 ms
(see also ADF1 register description).
After a reset pulse generated by the ISAC-S TE and the corresponding interrupt
(WOV, SAW or CISQ) t he actual reset source c an be re ad fro m the IS TA and
EXIR register.
BAC Bus Access Control
Only valid if the TIC-bus feature is enabl ed (MODE:D IM 2-0).
If this bit is set, the ISAC-S TE will try to access the TIC bus to occupy the C/I channel
even if no D- channel fram e has to be tra nsmitted. It should b e reset when the access
has been completed to grant a similar access to other devices transmitting in that IOM
channel.
11BACRSS 07
CODX0
Semicond uctor Group 166
Register Description
Note: Access is always granted by default to the ISAC-S TE/ICC with TIC-bus address
(TBA2-0, STCR register) "7", which has the lowest priority in a bus configuration.
CODX0 C/I Code 0 Transmit
Code to be transmitted in the C/I channel / C/I channel 0.
(refer to chapter 3.3.2)
4.2.4 MONITOR Receive Channel 0 MOR0 Read Address 32H
Contains the MONITOR data received in IOM MONITOR channel/
MONITOR channel 0 according to the MONITOR channel protocol.
4.2.5 MONITOR Transmit Channel 0 MOX0 Write Address 32H
Contains the MONITOR data to be transmitted in IOM MONITOR channel/
MONITOR channel 0 according to the MONITOR channel protocol.
4.2.6 Command/Indication Receive 1 CIR1 Read Address 33H
Value aft er reset: FFH
CODR1 C/I Code 1 Receive
Bits 7-2 of C/I channel 1
MR1 MR Bit
Bit 1 of C/I channel 1
MX1 MX Bit
Bit 0 of C/I channel 1
4.2.7 Command/Indication Transmit 1 CIX1 Write Address 33H
07
07
MX1MR1 07
CODR1
Semicond uctor Group 167
Register Description
Value aft er reset : FFH
CODX1 C/I Code 1 Transmit
Bits 7-2 of C/I channel 1
4.2.8 MONITOR Receive Channel 1 MOR1 Read Address 34H
Contains the MONITOR data received in IOM channel 1 according to the
MONITOR channel protocol.
4.2.9 MONITOR Transmit Channel 1 MOX1 Write Address 34H
Contains the MONITOR data to be transmitted in IOM channel 1 according to the
MONITOR channel protocol.
4.2.10 Channel Register 1 C1R Read/Write Address 35H
Contains the value received/transmitted in IOM channel B1 or IC1, as the case may
be (cf. C1C1, C1C0, SPCR register) .
4.2.11 Channel Register 2 C2R Read/Write Address 36H
Contains the value received/transmitted in IOM channel B2 or IC2, as the case may
be (cf. C2C1, C2C0, SPCR register) .
11 07
CODX1
07
07
07
07
Semicond uctor Group 168
Register Description
4.2.12 B1-Channel Register B1CR Read Address 37H
Conta i ns the value rece ived in IOM channel B1, if program med
(see C1C1, C1C0, SPCR register).
4.2.13 Synchronous Transfer Control RegisterSTCR Write A ddress 37H
Value aft er reset: 00H
TSF Terminal Specific Functions
0: No terminal specific functions
1: The terminal specific functions are activated, such as
– Watchdog Timer
– Subscriber/Exchange Awake (EAW).
In this case the EAW line is always an input signal which can serve as a request
signal from the subscriber to initiate the awake function in a terminal.
A falling edge on the EAW line generates an SAW interrupt (EXIR).
When the RSS bit in the CIX0 register is zero, a falling edge on the EAW line
(Subscriber Awake) or a C/I code change (Exchange Awake) initiates a reset
pulse.
When the RSS bit is set to one a reset pulse is triggered only by the expiration
of the watchdog timer (see also CIX0-register description).
Note: The TSF bit will be cleared on ly by a hardwar e re set.
TBA2-0 TIC-Bus Address
Defines the individual address for the ISAC-S TE on the IOM TIC bus
(see chapter 2.3.6).
This address is used to access the C/I- and D-channel on the IOM.
Note: One device liable to transmit in C/I- and D-fields on the IOM should always be given
the address value "7".
07
SC0SC1ST0ST1TBA0TBA1TBA2TSF 07
Semicond uctor Group 169
Register Description
ST1 Synchronous Transfer 1
When set , causes the ISA C-S TE to genera te a n SIN - inte r ru pt st atu s (ISTA regist er )
at the beg inning of an I OM frame.
ST0 Synchronous Transfer 0
When set , causes the ISA C-S TE to genera te a n SIN - inte r ru pt st atu s (ISTA regist er )
at the middle of an IOM frame.
SC1 Synchronous Transfer 1 Completed
After an SIN interrupt the processor has to acknowledge the interrupt by setting the
SC1 bit before the middle of the IOM frame, if the interrupt was originated from a Syn-
chronous Transfe r 1 (ST1). Otherwise an SOV interru pt (EXIR register) will be ge n-
erated.
SC0 Synchronous Transfer 0 Completed
After an SIN interrupt the processor has to acknowledge the interrupt by setting the
SC0 b it before the start of the next IOM frame, if the interrupt was originated from a
Synchron ou s Transf er 0 (ST0) .
Otherwise an SOV interrupt (EXIR register) will be generated.
Note: ST0/1 and SC0/1 are useful for synchronizing MP accesses and
receive/transmit operations.
4.2.14 B2-Channel Register B2CR Read Address 38H
Used only in terminal mo de (SPCR:SPM = 0).
Contains the value received in the IOM channel B2, if programmed
(see C2C1, C2C0, SPCR register).
07
Semicond uctor Group 170
Register Description
4.2.15 Additional Feature Register 1 ADF1 Write Address 38H
Value aft er reset: 00H
WTC1, 2 Watchdog Timer Control 1, 2
After the watchdog timer mode has been selected (STCR:TSF = CIX0:RSS = 1) the
watchdog timer is started.
During every time period of 128 ms the processor has to program the WTC1- and
WTC2 bit in the following sequence:
to reset and restart the watchdog timer.
If not, the timer expires and a WOV interrupt (EXIR) together with a reset pulse is
generated.
TEM Test Mode
In test mode (TEM = 1, PFS = 0) all layer-1 functions are disabled and the
ISAC-S TE behaves like an ICC (PEB 2070) device.
PFS Prefilter Select
These bits together determine the pre-filter delay compensation and the test mode
(layer 1 disabled) of the ISAC-S TE, as follows:
IOF IOM OFF. Used in terminal mode (SPCR:SPM = 0).
0: IOM interface is operational
1: IOM interface is switched off (DCL, FSC1, IDP0/1, BCL high impedance).
Note: IOF should b e set to "1" if exte rnal devices con nected to the IOM int erface should be
"disconnected" e.g. for power saving purposes or for not disturbing the internal IOM
connection between layer 2 and layer 1. However, the internal operation is
independent of the IOF bit.
ITF00IOFPFSTEMWTC2WTC1
07
WTC1 WTC2
1
0
1.
2. 0
1
TEM PFS Effect
0 0 No pre -filter (0 delay)
0 1 Pre-filter delay compensation 520 ns
1 1 Pre-filter delay compensation 910 ns
1 0 Test mode (layer 1 disabled)
Semicond uctor Group 171
Register Description
ITF Inter-Frame Time Fill
Selects the inter -frame time fill signal which is transmitted between HDLC frames.
0: idle (continuous 1 s),
1: flags (sequence of patterns: "0111 1110")
Note: In TE applications with D-channel access handling (collision resolution), the only
possible i nter -fram e time fil l signal i s idle (contin uous 1 s). Otherwise th e D chan nel
on the S/T bus cannot be accessed.
4.2.16 Additional Feature Register 2 ADF2 Read/Write Address 39H
Value aft er reset: 00H
IMS IOM Mode Selection
IOM-2 interface mode is selected when IMS = 1.
ODS Output Driver Selection
Tristate drivers (1) or open drain drivers (0) are used for the IOM interface.
D1C2-0 Data Strobe Control
These bits determine the polarity of the two independent strobe signals SDS1 as
follows:
The strobe signals allow standard combos or data devices to access
a progra m ma bl e chan ne l .
D1C0D1C1D1C2ODS000IMS 07
D1C2 SDS1D1C1 D1C0
0always low0 0
0high during B10 1
0 high during B21 0
0 high during B1 + B21 1
1
1
1
1
0
0
1
1
0
1
0
1
always low
high during IC1
high during IC2
high during IC1 + IC2
Semicond uctor Group 172
Register Description
4.2.17 MONITOR Status Register MOSR Read Address 3AH
Value aft er reset: 00H
MDR1 MONITOR Channel 1 Data Received
MER1 MONITOR Channel 1 End of Reception
MDA1 MONITOR Channel 1 Data Acknowledged
The remote end has acknowledged the MONITOR byte being transmitted.
MAB1 MONITOR Channel 1 Data Abort
MDR0 MONITOR Channel 0 Data Received
MER0 MONITOR Channel 0 End of Reception
MDA0 MONITOR Channel 0 Data Acknowledged
The remote end has acknowledged the MONITOR byte being transmitted.
MAB0 MONITOR Channel 0 Data Abort
4.2.18 MONITOR Control Register MOCR Write Address 3AH
Value aft er reset: 00H
MRE1,0 MONITOR Receive Interrupt Enable (IOM channel 1,0)
MONITOR interrupt status MDR1/MDR0, MER1/0 generation is enabled (1) or
masked (0 ).
MRC1,0 MR Bit Control (IOM Channel 1,0)
Determines the value of the MR bit:
0: MR always "1". In addition, the MDR1/MDR0 interrupt is blocked, except for the
first byte of a packet (if MRE1/0 = 1).
1: MR internally controlled by the ISAC-S TE according to MONITOR channel
protocol . In addi tion, the MDR1/MDR0 interrupt is enabled for al l r eceived bytes
according to the MONITOR channel protocol (if MRE1 0 = 1).
MAB0MDA0MER0MDR0MAB1MDA1MER1MDR1 07
MXC0MXE0MRC0MRE0MXC1MXE1MRC1MRE1 07
Semicond uctor Group 173
Register Description
MXE1,0 MONITOR Transmit Interrupt Enable (IOM channel 1,0)
MONITOR interrupt status MDA1/0, MAB1/0 generation is enabled (1) or
masked (0 ).
MXC1,0 MX Bit Control (IOM channe l 1,0)
Determines the value of the MX bit:
0: MX always "1 ".
1: MX internally controlled by the ISAC-S TE according to MONITOR channel
protoc ol.
4.2.19 S-, Q-Channel Rec eive Regi ster SQRR Re ad Address 3BH
Value aft er reset: 0XH
IDC Read-Back of Programmed IDC Bit (see SQXR register)
CFS R ead-Back of Programmed CFS Bit (see SQXR register)
CI1E Read-Back of Programmed CI1E Bit (see SQXR register)
SYN Synchronization State
The S/T re ceiver has synch ronized to th e received FA and M bits (1) or has not (0).
SQR1-4 Received S/Q Bits
Received S bits in frames 1, 6, 11 and 16, respectively.
SQR4SQR3SQR2SQR1SYNCI1ECFSIDC 07
Semicond uctor Group 174
Register Description
4.2.20 S, Q Channel Transmit Register SQXR Wr ite Address 3BH
Value aft er reset: 0FH
IDC IOM Direction Control
0: Master (normal) mode
Layer 2 transmits IOM channel 0 and 2 on IDP1, channel 1 on IDP0.
1: Slave (test) mode
Layer 2 transmits IOM channel 0, 1 and 2 on IDP1.
Note: Also refer to chapter 2.3.2
CFS Configuration Select
This bit determines clock relations and recovery on S/T and IOM interfaces.
0: Th e IOM interfa ce clock and fr ame signals are always act ive, "Power-Dow n" state
included.
The states "Power-Down" and "Power-Up" are thus functionally identical except
for the indication: PD = 1111 and PU = 0111.
With the C/I-command Timing (TIM) the processor can enforce the "Power-Up"
state.
With C/I-command Deactivation Indication (DIU) the "Power-Down" state is
reached again.
However, it is also possible to activate the S-interface directly with the
C/I-command Activate Request (AR 8/10/L) without the TIM command.
1: The IOM-interface clock and frame signals are normally inactive Power-Down").
For activating the S interface the "Power-Up" state can be induced by software
(SPU bit in SPC R register).
After that the S interface can be activated with the C/I-command Activate
Request (AR 8/10/L).
The "Power-Down" state can be reached again with the C/I command-
Deactivation Indication (DIU).
Note: After reset the IOM interface is always active. To reach the "Power-Down" state
the CFS bit has to be set.
SQX4SQX3SQX2SQX1SQIECI1ECFSIDC 07
Semicond uctor Group 175
Register Description
CI1E C/I Channel 1 Interrupt Enable
Interrupt generation of CIR0:CIC1 is enabled (1) or masked (0).
SQIE S-, Q-Interrupt Enable
Generation of CIR0:SQC status (and the accompanying CISQ interrupt is enabled
(1) or ma sked (0).
SQX1-4 Transmitted Q Bits
transmitted FA bits in frames 1, 6, 11 and 16, respectively.
Semicond uctor Group 176
Electrical Characteristics
5 Electrical Characteristics
Absolute Maximum Ratings
Note: Stresses above those listed here may cause permanent damage to the device.
Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Line Overload Protection
The maximum input current (under overvoltage conditions) is given as a function of the width
of a rectangular input current pulse (figure 54).
Figure 54
Test Condition for Maximum Input Current
Parameter Symbol Limit Values Unit
Voltage on any pin
with respect to ground VS– 0.4 to VDD + 0.4 V
Ambient te mperature under bias TA0 to 70 °C
Storage temperature Tstg – 65 to 125 °C
Maximum voltage on V DD VDD 6 V
ITS05678
Ι
t
Condition: All other pins grounded
t
WI
-S TEISAC
R
Semicond uctor Group 177
Electrical Characteristics
Transmitter Input Current
The destruction limits for negat ive input signals are given in figure 55. Ri ≥ 2 Ω.
Figure 55
The destruction limits for positive inpu t si gnals are given in figure 56. Ri ≥ 200 Ω.
Figure 56
ITD02337
0.05
0.5
5
50
10
-10 -9
10
-8
10
-7
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10 1 s
A
WI
t
Ι
1
10
100
ITD02340
0.05
0.5
5
50
10
-10 -9
10
-8
10
-7
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
10 1 s
A
w1
t
Ι
Semicond uctor Group 179
Electrical Characteristics
DC Characte ristics
TA = 0 to 70 °C; VDD = 5 V ± 5 %, VSSA = 0 V, VSSD = 0 V
Parameter Symbol Limit Values Unit Test Condition Remarks
min max
L-input voltage VIL – 0.4 0.8 V All pins
except
SX1,2,
SR1,2
H-input voltage VIH 2.0 VDD
+0.4 V
L-output voltage
L-output voltage
(IDP0)
VOL
VOL1 0.45
0.45 V
VIOL = 2 m A
IOL = 7 mA
H-output voltage
H-output voltage VOH
VOH 2.4
VDD
–0.5
V
VI
OH = – 400 µA
IOH = – 100 µA
Power
supply
current
power
down
ICC 1.5 mA VDD =5V
Inputs at
VSS /VDD
No output
loads
except SX1,2
(50 Ω load)
oper-
ational
(96 kHz) 17 mA DCL = 1536 kHz
Emergency
B1 = FFH,
B2 = FFH,
D = 1
7.7 mA DCL = 1536 kHz
B1 = FF
H
,
B2 = FF
H
,
D = Flag
7.95 mA DCL = 1536 kHz
B1 = 55
H
,
B2 = FF
H
,
D = Flag
8.75 mA DCL = 1536 kHz
B1 = 00
H
,
B2 = FF
H
,
D = Flag
10 mA DCL = 1536 kHz
Input leakage
current
Output lea kage
current
ILI
ILO
10
10
µA
µA
0V<VIN <VDD to 0 V
0V<VOUT <VDD to 0 V
All pins
except
CP/BCL,
X2,
SX1,2,
SR1,2,
A0, A1,
A3, A4
Semicond uctor Group 180
Electrical Characteristics
Note: 1) Due to the transformer, the load resistance seen by the circuit is four times RL.
Input leakage
current
internal pull-down
ILIPD 120 µA0V<VIN <VDD to 0 V A0, A1,
A3, A4,
CP/BCL,
X2
Absolute value
of output pulse
amplitude
(VSX2–VSX1)
V
X2.03
2.10 2.31
2.39 V
VRL = 50 Ω1)
RL = 400 Ω1) SX1,2
Transmitte r out-
put current IX7.5 13.4 mA RL = 5.6 Ω1)
Transmitte r out-
put impedance RX10
0kΩ
ΩInactive or during binary one
during binary zero RL = 50 Ω
Receiver
output volt age VSR1 2.35 2.6 V IO<5µA SR1,2
Receiver
threshold voltage
VSR2 –VSR1
VTR 225 375 mV Dependent on peak level
DC Characte ristics
TA = 0 to 70 °C; VDD = 5 V ± 5 %, VSSA = 0 V, VSSD = 0 V (cont’d)
Parameter Symbol Limit Values Unit Test Condition Remarks
min max
Semicond uctor Group 181
Electrical Characteristics
Capacitances
TA=25°C,VDD =5V±5%,VSSA =0V,VSSD =0V,fc=1 MHz, unmeasuredpins grounded.
Recommended Oscillator Circuits
Figure 57
Oscillator Circuits
Crystal Specification
Note: The load capacitance CL depends on the recommendation of the crystal
specificat ion. Typical values for CL are 22 …33 pF.
Unit
pF
pF
pF
pF
Parameter Symbol
Load capacitance CL
Input capacitance
I/O capacitance CIN
CI/O
Output capacitance
against VSSA
COUT
50
7
7
10
Remarks
min. max.
Limit Values
pFInput capacitance CIN 7XTAL1,2
All pin s except
SR1,2
SX1,2
SR1,2
ITS00764
7.68 MHz
XTAL1
2XTAL XTAL2
1XTAL
N.C.
Oscillator
External
Signal
Crystal Oscillator Mode Driving from External Source
18
1919
18
pF33
33 pF
C
L
L
C
Unit
pF
ppm
Parameter Symbol
Load capacitance CLmax. 50
Frequency calibration tolerance max. 10 0
Oscillator mode fundamental
Limit Values
MHzFrequency f7.680
Semicond uctor Group 182
Electrical Characteristics
XTAL1 Clock Characteristics (external oscillator input)
AC Characte ristics
T A = 0 to 70 °C, V DD = 5 V ± 5%
Inputs are driven to 2.4 V for a logical "1" and to 0.4 V for a logical "0". Tim i ng measurements
are made at 2.0 V for a logical "1" and 0.8 V for a logical "0". The AC-testing input/output
waveforms are shown in figure 58.
Figure 58
Input/Output Waveform for AC Tests
Parameter
Duty cycle 1:2 2:1
min. max.
Limit Valu es
ITS00621
= 150
Load
C
Test
Under
Device
0.45
2.4 2.0
0.80.8
2.0 Test Points
pF
Semicond uctor Group 183
Electrical Characteristics
Microprocessor Interface Timing
Siemens/Intel Bus Mode
Figure 59
Micro processor Read Cycle
Figure 60
Microprocessor Write Cycle
Figure 61
Multiplexed Address Timing
ITT00712
RD x CS
AD0 - AD7
t
RD
Data
t
DF
RR
tt
RI
ITT00713
WR x CS
AD0 -AD7
t
DW
Data
t
WD
WW
tt
WI
ITT00714
WR x CS
AD0 - AD7
t
LA
CSxRD or
Address
ALE
t
ALS
t
AL
t
AA
t
AD
Semicond uctor Group 184
Electrical Characteristics
Figure 62
Non-Multiplexed Address Timing
Motor o l a Bu s Mo de
Figure 63
Microprocessor Read Timing
Figure 64
Microprocessor Write Cycle
ITT00715
WR x CS
A0 - A5
t
AH
t
AS
Address
CSxRD or
ITT00716
CS x DS
D0 - D7
t
RD
Data
t
DF
DSD
t
RR
tt
RI
R/W
t
RWD
Semicond uctor Group 185
Electrical Characteristics
Figure 65
Non-Multiplexed Address Timing
Microprocessor Interface Timing
ITT00718
CS x DS
AD0
t
AH
t
AS
- AD5
Unit
ns
ns
ns
ns
ns
Parameter Symbol
ALE pulse width tAA 50
Address setup time to ALE tAL 15
Address hold time from ALE tLA 10
Address setup time tAS 25
Address hold time tAH 10
min. max.
Limit Values
nsAddress latch setup time to WR, RD tALS 0
nsALE guard ti me tAD 15 nsDS delay after RW setup tDSD 0nsRD pulse width tRR 110 nsData output delay from RD tRD 110 nsData float from RD tDF 25 nsRD control interval tRI 70 nsW pulse width tWW 60 nsData setup time to W × CS tDW 35 nsData hold time from W × CS tWD 10 nsW control interval tWI 70
Semicond uctor Group 186
Electrical Characteristics
Serial Interface Timing
Figure 66
IOM® Timing (TE mode)
IOM® Timing
ITD05435
t
FSD
t
IIS
IIH
t
t
IOD
BCD
t
BCD
t
SDD
t
(O)FSC1
DCL (O)
( )IDP0/1
(O)IDP0/1
(O)SDS1
(O)BCL
Ι
Unit
ns
ns
ns
ns
ns
Parameter Symbol
IOM output data delay tIOD 20
IOM input data setup tIIS 20
IOM input data hold tIIH 20
Strobe signal delay tSDD
Bit clock delay tBCD –20
100
120
20
min. max.
Limit Values
nsFSC1 strobe delay tFSD –20 20
Test Condition
IOM-2
IOM-2
Semicond uctor Group 187
Electrical Characteristics
HDLC Mode (ADF2: IMS = 0, ADF1: TEM = 1, MODE: DIM2 – 0 = 101 – 111)
Figure 67
FSC1 (strobe) Cha racteristic s
HDLC Mode Timing
Unit
ns
ns
ns
ns
ns
Parameter Symbol
FSC1 set-up time tFS1 100
FSC1 hold time tFH1 30
Output data from high impedance to active tOZD
Output data delay from DCL tODD 20
Input data setup tIS 10
80
100
min. max.
Limit Values
nsOutput data from active to high impedance tODZ 40
nsInput data hold tDH 30
Semicond uctor Group 188
Electrical Characteristics
Clock Timing
The clocks are summarized in table 20, with the respective duty ratios.
Table 20
ISAC®-S TE Clock Signals (IOM®-2 mode)
The 1536-kHz clock is phase-locked to the receive S signal, and derived using the internal
DPLL and the 7.68 MHz ± 100 ppm crystal.
A phase tracking with respect to "S" is performed once in 250 µs. As a consequence of this
DPLL tracking, the "high" state of the 1536-kHz clock may be either reduced or extended by
one 7.68-MHz period (duty ratio 2:2 or 4:2 instead of 3:2) once every 250 µs. Since the other
signals are derived from this clock, the "high" or "low" states may likewise be reduced or
extended by the same amount once every 250 µs.
The phase relationships of the clocks are shown in figure 68.
Figure 68
Phase Relationships of ISAC®-S TE Clock Signals
DCLApplication
o:1536 kHz*
3:2
TE
FSC1
o:8 kHz*
1:2
SDS1
o:8 kHz
1:11
2:10
BCL
o:768 kHz*
1:1
*)Synchronous to receive "S" line
ITD05427
7.68 MHz
kHz1536
768 kHz
*
Synchronous to receive S/T. Duty Ratio 3 : 2 Normally
*
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Electrical Characteristics
Figure 69
Timing Relationships between ISAC®-S TE Clock Signal s
Table 21
ITD05428
DCL
BCL
FSC1
SDS1
t
BCD
t
BCD
t
FSD
SBD
t
t
SSD
R
(IOM -2)
Unit
ns
ns
ns
Parameter Symbol
Bit clock delay tBCD –20
SDS1 delay from DCL tSDD
SDS1 delay from BCL tSBD
20
120
120
min. max.
Limit Values Condition
IOM-2
IOM-2
IOM-2
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Electrical Characteristics
Figure 70
Definition of Clock Period and Width
Table 22
DCL-Clock Characteristics (IOM®-2)
ITT00723
t
WH WL
t
t
P
3.5 V
V0.8
Unit
ns
ns
ns
Parameter Symbol
(TE) 1536 kH z tPO 520
tWHO 240
tWLO 240
782
541
281
min. max.
Limit Values Test Condition
osc ± 100 ppm
osc ± 100 ppm
osc ± 100 ppm
651
391
260
typ.
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Electrical Characteristics
Jitter
In TE mode, the timing extraction jitter of the ISAC-S conforms to CCITT Recommendation
I.430 (– 7 % to + 7 % of the S-interf ace bit period).
Description of the Receive PLL (RPLL) of the ISAC-S TE
The receive PLL performs phase tracking each 250 µs after detecting the phase between the
F/L transition of the receive signal and the recovered clock. Phase adjustment is done by
adding or subtractin g 130 ns to or form a 1.536-MHz clock cycle. The 1.536-MHz clock is than
used to generate any other clock synchroni zed to the line .
During (re)synchronization an int ernal reset condition may effe ct the 1.536 -MHz clock to have
high or low times as short as 130 ns. After the S/T-interface frame has achieved the
synchronized state (after three consecutive valid pairs of code violations) the FSC output is set
to a specific phase relationship, thus causing once an irregu lar FSC timi ng.
Reset
Table 23
Reset Signal Characteristics
Figure 71
Reset
Unit
ms
Parameter Symbol
Length of active
high state tRST 4
2 x DCL
clock cycles
min.
Limit Valu es Test Condition
Power-on/Power-Down
to Power-U p (Standby)
During Powe r-Up (Standby)
ITD02396
RST
t
RST
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Low Level Controller
6ISAC
®
-S TE Low Level Controller
The following paragraphs outline the functionality and structure of a software driver example
for the ISAC-S TE. This example is based on the Siemens Low Level Controllers (LLC’s) for
Basic Access IC which are available in C source code. The ISAC-S TE software drive r will be
also referred to as LLC or ISAC-S LLC.
It should be noted that the ISAC-S LLC does not access the complete palette of device
functions but rather a subset of them. For example not all message transfer modes are
supported. Please refer to paragraph ’Architecture and Functions’ for a more detailed
description.
The ISAC-S LLC presented here has been successfully tested in the Siemens ISDN PC
development system. Correct operation with a higher layer software has been verified by using
the Siemens ISDN-Software Development and Evaluation System (SIDES) and the Siemens
ISDN-Operational Software (IOS).
The ISAC-S LLC also apply for the ISAC®-S TE with the limitation of TE functionality only.
There is no adaptation in the listing to this limitation.
6.1 Architecture and Functions
The ISAC-S TE LLC may be divid ed into two major parts, one for layer 1 control, the ’SBC part’
and one for directing the HDLC-controller operations, the ’ICC part’. The naming conventions
’SBC part ’ and ’ICC part’ have been in troduced for two reasons: The first is that the ISAC-S TE
may be viewed as the one-chip integration of the Siemens ISDN Communications Controller,
PEB 2070 ICC, a nd the S- Bus Inter face Circuit, PEB 2080 SBC. The second is tha t the SIPB -
mainboard firmware, the basis for this example software, actually uses the same code to
control either an ISAC-S TE or an ICC-SBC combination.
The ISA C-S TE LLC con sists of driver functions and interrupt server. The driver functions
are implemented as a set of C functions which are responsible for interpreting hardware
related commands from the higher layers and carrying out the appropriate actions at the
hardware level. Driven by hardware interrupts, the interrupt server analyses the hardware
event and informs the higher software layers of th at event.
It should be noted that th is implementation has a ttempted to remove as ma ny protocol spe cific
functions as possible from the LLC and to locate them instead in the higher layer protocol itself.
This has the advantage of making the LLC- more general and less likely to be in need of re-
programming for di fferent protocols.
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Low Level Controller
OPERATING SYSTEM and
Higher Level Protocol Software
Figure 73
LLC Architecture
The ISAC-S TE LLC supports following standard functions:
– Initialization of the SBC (layer 1) part.
– Activation of layer 1.
– Deactivation of layer 1.
HDLC-controller initializatio n.
The following HDLC-controller message transfer modes are supported:
auto-mode: ful l two byt e address c ompar e, LAP D supp ort.
non-auto mode: full two byte address compare.
transparent mode 3: high byte address compare; called 'TRANSPARENT' mode in
the LLC.
transparent mode 2: no address compare; called 'EXTENDED TRANSPARENT'
mode in the LLC.
HDLC framin g with two byte address field is assu med.
ITS05679
HDLC Controller
related Functions
Driver Functions
ICC Part ICC PartSBC Part SBC Part
Layer-1
Functions
FUNCTION CALLS
...
Status/
Error Messages Received
Frames MMU - Service
Requests
Interrupt Server
Evaluation of Interrupt Cause
-S TEISAC
R
Semicond uctor Group 194
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– HDLC-frame transmission.
– Programming of TEI and SAPI values.
– HDLC-transceiver control.
– Local test loop switching.
The LLC assumes that the ISAC-S TE is operating in an IOM-2 TE configuration.
In addition to the ISAC-S TE standard functions supporting the ISDN-basic access, the ISAC-S
TE contains optional, terminal specific functions. These terminal specific functions (watchdog
and ex terna l awake) are not supporte d by this LLC.
6.2 Summary of LLC Functions
6.2.1 Layer-1 Related Functions
Mnemonic Purpose
ActL1_SBC Layer-1 activation.
DeaL1_SBD Layer 1 deactivation.
ArlL1_SBC Activation of a local loop.
EnaClk_SBC Enable clocking in power down mode.
InitL1_SBC Layer-1 initialization and reset.
ResL1_SBC Layer-1 reset.
IntL 1_SBC Handling of CISQ interr upts.
The layer 1 related functions call DECODE_L1_STATUS to report a L1 status change to a
higher layer software.
6.2.2 HDLC-Controller Related Functions
Mnemonic Purpose
InitLay2_IC C HDLC-controller initialization.
Loop_ICC Testloop activation at the serial outputs of the IOM interface.
ResetHDLC_ICC HDL C-transceiver reset.
RecReady_ICC Setting the HDLC receiver ready or not ready.
SendFra me _I CC HDLC-frame transmission.
StoreSAPI_ICC SAPI programming.
StoreTEI_ICC TEI programming.
Int_ICC Handling of XPR, RSC, TIN and EXI interrupts.
Rx_ICC Handling of RPF and RME interrupts.
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6.2.3 External Functions
The LLC-program listing shows some references to external functions (indicated by an
’IMPORT’ declaration). These functions are used by the LLC but are not part of it. These
external functions must be provided by the operating system or a higher layer protocol
software.
MMU_req ()
By calling MMU_req the ISAC-S TE LLC requests memory for the temporary storage of a
received data frame. The memory management unit (MMU) of the operating system has to
provide a memory buffer of the required size (max. 260 bytes).
MMU_ free ()
MMU_free is the counterpart to MMU_req. The operating system can release a previously
allocated memory buffer.
STRING_IN () and STRING_OUT ()
STRING_IN and STRING_OUT are assembler written functions for fast input and output of
data frames from/to the ISAC-S FIFO.
ENTERNOINT () and LEAVENOINT ()
ENTERNOINT and LEAVENOINT are called to disable and enable all system interrupts in time
critical sections.
Decode_S_Frame_BASIC ()
Decode_S_Frame_BASIC is called by the LLC-interrupt server to transfer a received HDLC
S frame to a higher layer protocol software.
Following information is p asse d to Decode_S_Frame_BASIC:
’pei’: 1-byte value identifying the performed address recognition. The bits 0, 1 and 2 of
’pei’ represent the bits TA, SA0 and SA1 of the ISAC-S’ RSTA register.
’sapi’: 1-byte value representing the received HDLC SAPI address byte. Bit 1 of ’sapi’ is
the C/R bit value (RSTA:CR). The most significant 6 bits of ’sapi’ are 0 in
auto-mode, non-auto mode and transparent mode.
’tei’: 1-byte value representing the received HDLC TEI address byte. ’tei’ is 0 in
auto-mode and non-auto mode.
’ctrl’: 2-byte value representing the contents of the received HDLC-control field.
’frame_status’: 1 byte value
= 0 × 00: frame is valid.
= 0 × 80: frame is mutilated (last byte of two byte control field missing).
= 0 × 82: frame is too long. S frame with I field.
’M128’: 1-byte value. 0 in modulo 8 operating mode (1-byte control field), 1 in modulo 128
operating mode (2-byte control field). For correct decoding of ’ctrl’ above.
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Decode_U_Frame_BASIC ()
Decode_U_Frame_BASIC is called by the LLC-interrupt server to transfer a received HDLC U
frame to a higher layer protocol software.
Following information is p asse d to Decode_U_Fra me_BASIC:
’pei’: (refer to Decode_S_Frame).
’sapi’: (refe r to Decode_S_Frame).
’tei’: (refer to Decode_S_Frame).
’ctrl’: 1-byte value representing the contents of the received HDLC control field.
PassLongFrame_BA SIC ()
PassLongFrame_BASIC is called by the LLC-interrupt server to transfer received HDLC I and
UI frames to a higher layer protocol software.
The LLC passes a pointer to a structure (FRAME_PASS) containing information about the
received frame to PassLongFrame_BASIC. Please refer to the following paragraph for a
description of this structure.
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6.3 LLC-Code Elements
6.3.1 Structures
The Structure ’ISAC’
As the various routines in the LLC require facilities to store information about the device they
control, the global variabel ’pt’ of the type ’ISAC’ has been introduced. The type ’ISAC’ is a
structure containing imperative information elements. These information elements are listed
below:.
Status Information
pt_op_mode operating mode of the ISAC-S TE HDLC controller (auto-mode, non-
auto mode…)
pt_state Flags of 'pt_state' indicate the various device states.
pt_Mo dulMode hardware c onfiguration (TE or NT-S)
I/O buffer related elements
These el ements are used when the HDLC data is tran smitted or rece ived. In both the tran smit
and rece ive dir ectio ns ad di ti on al R AM is r eq uir ed to store d ata on a n i nterm e di ate basi s. This
buffer will be referred to as the data frame. Related information is stored in the following
elements:
Transmit buffer pointers
pt_tx_start pointer to the starting point of the data frame for transmission
pt_tx_curr pointer to the present byte to be sent
Receive buffer pointers
pt_rx_start pointer to the starting point of the receive data frame.
pt_rx_curr pointer to the next free position in the receive buffer.
Data byte counters
pt_tx_cnt number of bytes yet to be transmitted
pt_rx_cnt number of bytes currently received
The following elements are used to store the type of frame:
pt_rx _frame type of received fr ame.
pt_tx_frame type of transmitted frame.
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The Structure ’FRAME_PASS’
The variable ’fp’ of the type FRAME_PASS is used when the LLC-interrupt server has received
a valid HDLC I or UI frame. A pointer to ’fp’ is passed to PassLongFrame_BASIC.
FRAME_PA SS contains all informati on ab out the receiv ed HDLC frame . Following elements
are used:
mmu_buff start of MMU buffer which is used for the temporary storage of that HDLC
frame.
start_of_i_data Start of the I-data field in this MMU buffer.
i_data_cnt Number of bytes in the I-data field.
Two_byte_cf 0 for a one byte HDLC control field, 1 for a two byte HDLC-control field.
ctrl_field HDLC-control field.
pei 1-byte value identifying the performed address recognition. The bits 0, 1
and 2 of ’pei’ represent the bits TA, SA0 and SA1 of the ISAC-S’ RSTA
register.
frame Type of HDLC frame; 0 = I frame, 1 = UI frame.
sapi Received HDLC SAPI address byte. Bit 1 of ’sapi’ is the C/R-bit value
(RSTA:CR). The most significant 6 bits of ’sapi’ are 0 in auto-mode, non-
auto mode and transparent mode.
tei Received HDLC TEI-a ddress byte. ’tei’ is 0 in auto-mode and non-auto
mode.
6.3.2 Definitions and Naming Conventions
Public functions are declared with an EXPORT (only for better readability). External functions
are imported using an IMPORT which is the redefinition of C’s ’extern’. Any function which is
only used locally is d eclare d with a LOCAL (= ’static’).
6.3.2.1 Type Definitions
For reference here is a list of the type definitions used in the LLC’s.
type defi nitions meaning
BYTE one byte value
WORD w ord = two byte value
FPTR far pointer to BYTE
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6.3.2.2 Macro Definitions
Error conditions and other states of the ISAC-S TE must be reported to higher layers. This
reporting is realized by a few macros which are executed when such conditions are detected.
These macr os can be mapp ed to any form o f message a higher layer softwa re requ ires. An y
kind of immed iatel y necessa ry action s may be def ined in t hos e macros as we ll. By u sing such
constructs the code can be kept compact and clearly readable.
Layer 1 Related Status Message
DECODE_L1_ST ATUS for L1 status (IC-channel indicati on) deco ding.
HDLC Controller Related Status and Error Messages
CRC_ERROR CRC error.
MISSING_ACKNOWLEDGE A ’Missing HDLC I-frame acknowledge’ is generated
when an ackn owl ed ge me ssag e for a previou sl y
sent I frame is outstanding and the HDLC-message
tran sfer mode is c hanged fro m auto-mode to non-
auto mode. An outstanding acknowledge is
indicated by the ISAC-S TE in register STAR2 (’timer
recovery status’ and ’waiting for acknowledge’ bits).
MMU_ERROR No memory available to store incoming frame.
N201_ERROR N201 error, HDLC frame is too long.
PEER_REC_READY Peer receiver ready.
PEER_REC_BUSY Peer receive busy.
PROTOCOL_ERROR Pr otocol error (PCE interrupt).
REC_FRAME_ OVERFLOW Receive frame overflow.
REC_DATA_OVERFLOW Receive data overflow (RDO interrupt).
REC_ABORTED Receive ab orted (RAB interrupt).
TX_ACKNOWLEDGE Transmit frame acknowledge.
TIN_ERROR TIN interrupt, status enquiry.
TX_DATA_UNDERRUN Transmit data underrun (XDU interrupt).
XMR_ERROR Transmit message repeat ind ication (XMR interru pt).
Following macros are used when a ’timer recovery status’ (register STAR2, bit TREC) is
recognized.
ENABLE_TREC_STATUS_CHECK enable ’timer reco very status ’ check procedure.
DISABLE_TREC_STATUS_CHECK disable ’timer recovery status’ check procedure.
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6.4 Interrupts
Int_ICC is to be called in the case of ISAC-S TE interrupts. The following interrupts are handled
directly in Int_ICC:
’Transmit pool ready’ interrupt (ISTA:XPR)
’Timer’ interrupt (ISTA:TIN).
’Receive Status Change’ interrupt (ISTA:RSC).
’Extended’ interrupt (ISTA:EXI).
The ’Receive Pool Full’ (ISTA:RPF) and ’Receive Message End’ (ISTA:RME) interrupts are
handl ed by functi on RX_ICC . The ’ CI or SQ channel ch ange’ int errupt (IS TA:CISQ) is handled
by IntL1_SBC .
Please note that the following interrupts are not handled by the interrupt service routine
described here:
ISTA:SIN (synchronous transfer interrupt)
EXIR:SOV (synchronous transfer overflow)
EXIR:MOS (monitor status) is handled by external functions w hich are not part of this
description.
EXIR:SAW (subscriber awake)
EXIR:WOV (watchdog timer overflow)
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Low Level Controller
6.5 LLC-Routine Reference
6.5.1 ISAC®-S TE Layer-1 Functions: The SBC Part
ActL1_SBC ()
Initiates layer-1 activation. The appropriate CI code (activate request) is written to the CI
channel if the layer 1 is not alrea dy activated. Ac tL1_SBC then r eturns with ACK_DONE. The
subsequent status changes of the SBC will cause CI-channel status change (CISQ) interrupts
and these will be eval uated in the laye r-1 interrupt service rou tine IntL1_ SBC.
If the layer 1 is already activated nothing is carried out but ActL1_SBC calls
DECODE_L1_STATUS to report the activated state.
DeaL1_SBC ()
Initia tes layer 1 de activation. The appropriate CI code is written to the CI channel if the layer 1
is not already deactivated. The subsequent layer 1 status changes cause CI channel status
change (CISQ) interrupts and these will be evaluated in the layer 1 interrupt service routine
IntL1_SBC.
If the layer 1 is already deactivated nothing is carried out but DeaL1_SBC calls
DECODE_L1_STATUS to report the deactivated state.
ArL1_SBC ()
Activates a local loop in the SBC. The appropriate CI code (activate request loop) is written to
the SBC. ArL1_SBC returns with ACK_DONE. The subsequent status changes of the SBC will
generate CISQ interrupts and these will be evaluated and reported in the layer-1 interrupt
servic e ro uti n e IntL 1_SBC.
EnaClk_SBC ()
EnaClk_SBC enables clocking in TE configurations when the layer 1 is in power-down state.
If first tests if clocks are actually there. If there are clocks the function returns with FALSE. If
there are no clocks (power-down state) the power-up procedure is implemented. The SPU bit
in register SPCR is set. The TIM code is written to the CI channel. EnaClk_SBC waits until the
power-up state (PU) is indicated before the SPU bit is reset to 0. The routine then returns with
TRUE.
InitL1_SBC ()
Initializes and resets the layer-1 controller (ResL1_SBC). Timing mode 0 is set and the TIC-
bus address is also programmed.
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ResL1_SBC ()
This routine resets the layer 1 part of an ISAC-S. It also checks that the layer 1 part is operating
correctly.
Reset procedure:
A software reset command (RS) is sent to the layer 1 part via the IOM CI0 channel.
ResL1_SBC waits for the expected new state (EI) if no timeout condition occurs and issues a
release command (DIU).
If the new state (EI) is not observed the ISAC-S layer 1 part will be deemed to b e defective.
IntL1_SBC () Interrupt Handler
Handles the CISQ interrupts which indicate changes in the layer 1 status. The final
confirmation of deactivation is carried out here. The actual layer 1 state is evaluated by reading
register CIR0 . The following is then ca rried out:
If the CI-channel indication is ’pending deactivation’ state (DR), DIU is sent to deactivate the
layer 1.
If the indication is an ’activation indication’ (AI) the activation must be confirmed from the TE
side. IntL1_SBC does it automatically by writing an ’activation request’ (AR). In this way this
requirement of the ISAC-S TE is transparent to the higher protocol layers.
After every CI-channel status change interrupt (CISQ) DECODE_L1_STATUS is called to
report the current layer-1 state.
6.5.2 ISAC®-S TE HDLC-Controller Related Functions: The ICC Part
InitPeitab_ICC ()
Initializes the local variable ’pt’. InitPeitab_ICC is to be called once during the system
initia li za tion ph ase.
InitLay2_ICC ()
Initializes the HDLC controller. The function arguments allow the selection of the HDLC-
controller message transfer mode (auto-mode, non-auto mode, ...), one or two byte HDLC-
control field operatio n (modulo 8 or 128) and the set ting of the IS AC-S TE inte rnal hardware
timer.
After InitLay2_ICC is called the TEI values for a Broadcast Link are programmed (TEI = FF
hex). The HDLC controller is not r ese t.
StoreTEI_ICC ()
StoreTEI_ICC is used to program a TEI value in register TEI1 or TEI2 depending on the
function argume nt value.
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StoreSAPI_ICC ()
StoreSAPI_ICC is used to program a SAPI value in register SAP1 or SAP2 depending on the
function argume nt value.
RecRea d y_ICC ()
Sets HDLC receiver ready or not ready depending on the function argument value.
ResetHDLC_ICC ()
ResetHDLC_ICC resets the HDLC controller. Status flags of the local variable ’pt’ indicating
any on -going data transmissions or receptions are reset and memory bu ffers are released.
SendFrame_ICC ()
SendFrame_ICC initiates the transmission of HDLC frames (S, U, I, UI frames).
A frame can not be sent if the transmit path is still in use, i.e. if the previous transmission is not
finished, if the timer recovery state is indicated (only for I frames) or if the XFIFO is blocked
(STAR:XFW bit).
If the transmission is begun the interrupt handler (Int_ICC) will handle subsequent tasks, for
example shifting remaining data bytes into the XFIFO or calling the MMU to release the
memory bu ffer.
Loop_ICC ()
Switches te stloop at the IOM inte rface on o r off, i. e. connects int ernally t he data up stream and
data downstream lines. This is achieved through setting/resetting the TLP bit in register SPCR.
If the layer-1 part does not deliver clocks while in the deactivated state the clocks will be
enabled when the loop is switched on by means of EnableClk_BASIC. In the Siemens Low
Level Controllers for BASIC access ICs EnableClk_BASIC is a function pointer which
addresses EnaClk_SBC if an ISAC-S or SBC(X) is used. When the loop is switched off the
layer 1 part will return to its normal dea c tivated state.
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Int_ICC () Interrupt Handler
Evaluates and handles the ISAC-S TE interrupts.
Interrupt service procedure:
The bits of the interrupt status register ISTA are scanned. XPR, TIN, RSC, and EXI interrupts
are ha ndled directly by In t_ICC. For RP F and RME inte rrupts the fun ction RX_ICC i s called,
for CISQ interrupts IntL1_SBC is called. The interrupt related actions performed are:
– XPR(transmit pool ready) interrupt, but no TIN and no PCE (EXIR:PCE) interrupt:
a) HDLC controller reset was given previously.
b) last transmission is finished. The XFIFO will be loaded if there are more bytes to
be sent. If not, a 'transmit frame acknowledge' can be generated (if depends on
the message transfer m ode and some other conditions).
– TIN interrupt:
The HDLC controller's int ernal ti mer has expired (in auto -mode only).
– RSC (receiver status change of remote station) interrupt:
A status change of the remote station's receiver has been detected. This is reported to the
higher layers.
– EXI (extended) interrupt:
One of the six non-critical interrupts has been generated. The exact cause is read from
register EXIR and reported to the higher layers.
RX_ICC () Interrupt Handler
Handle s the re ceiv e pool full an d rece ive me ssage end (RPF and RME) i nterrupt s if TIN an d
PCE (EXIR:PCE) interrupt are not indicated. Received frames are handed over to the higher
software levels. Errors detected during the frame reception are reported to the higher layers.
RPF interrupt: 32 data bytes are in the RFIFO. The end of the received frame is yet to be
received and the message is not complete.
RME interrupt: The receive m essage is complete. The RFIFO contains the la st bytes of a
frame greater than 32 bytes long or a complete frame. In the case of a
long frame the b eg inning of this fram e will already have been received
using the RPF interrupt. Address and control field information is
examined, the type of frame (HDLC U-, UI-, I- or S frame) is determined and
the validity of the frame is checked. Finally the frame or a error condition
message is sent to the higher layers.
Check_TREC_status_ICC ()
Check_TREC_status_ICC () is called periodically by the operating system, if 'timer recovery
status' (STAR2:TREC) was detected during a previous XPR interrupt handling. A 'transmit
frame acknowledge' for an HDLC I frame is generated if the TREC status is left and no timer
interrupt (ISTA:TIN) is indicated.
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6.6 Listing of Driver Routines
/***************************************************************************/
/* */
/* SIEMENS ISDN-Userboard (c) 1987-1993 */
/* ====================== */
/* */
/* Firmware: driver functions for ICC/ISAC-S/ISAC-P */
/* File : icc.c */
/* */
/***************************************************************************/
/* Include Files */
/* ============= */
#include "def.h"
#include "basic.h"
#include "message.h"
/* Import Functions */
/* ================ */
/* from crt0.asm */
IMPORT void STRING_IN ();
IMPORT void STRING_OUT ();
/* from basic00.c */
IMPORT PEITAB *GetPeitab_BASIC ();
/* from basic_l1.c */
IMPORT void IntLay1_BASIC ();
IMPORT void ResetLay1_BASIC ();
IMPORT int EnableClk_BASIC ();
/* from basic_l2.c */
IMPORT void PassLongFrame_BASIC ();
IMPORT void Decode_S_Frame_BASIC ();
IMPORT void Decode_U_Frame_BASIC ();
/* from mmu.c */
IMPORT int MMU_free ();
IMPORT FPTR MMU_req ();
/* from mofc.c */
IMPORT int IntMon_MOFC ();
IMPORT int Wr_IntMon_MOFC ();
/* Export Functions */
/* ================ */
EXPORT int Assign_ICC ();
EXPORT void Check_TREC_status_ICC ();
EXPORT int InitLay2_ICC ();
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Low Level Controller
EXPORT void InitPeitab_ICC ();
EXPORT void Int_ICC ();
EXPORT int Loop_ICC ();
EXPORT int SwitchB_ICC ();
EXPORT int RecReady_ICC ();
EXPORT int ResetHDLC_ICC ();
EXPORT int StoreTEI_ICC ();
EXPORT int StoreSAPI_ICC ();
EXPORT int SendFrame_ICC ();
/* Local Functions */
/* =============== */
LOCAL void RX_ICC ();
/* Variables */
/* ========= */
IMPORT unsigned int interrupt_act;
/* Function Declarations */
/* ===================== */
/***************************************************************************/
/* */
/* Function: InitPeitab_ICC () */
/* Parms : ’*pt’ pointer to the assigned PEITAB array element */
/* ’base’ address of detected ICC/ISAC */
/* purpose : initialization of the PEITAB elemtn for an ICC / ISAC-S */
/* */
/***************************************************************************/
EXPORT void
InitPeitab_ICC (pt, base)
register PEITAB *pt;
IO_PORT base;
{
BYTE version;
IO_PORT reg_rbch = base + ICC_RBCH;
/* read the ICC/ISAC-S (ISAC-P) */
/* version number */
/* 0 for versions A1, A2, .. */
/* 1 and greater for versions */
/* 2.x [Bx] (x=1,2,3,4) and later */
version = inp (reg_rbch);
/* and set the device identifier */
if (version != 0) /* accordingly */
{
if (pt->pt_device == PT_ICC)
pt->pt_device = PT_ICC_B;
if (pt->pt_device == PT_ISAC_S)
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pt->pt_device = PT_ISAC_S_B;
}
pt->pt_io_base = base; /* store the base (IO) address */
/* the following structure */
/* elements store the register IO */
/* addresses (e.g. for FIFOs, ISTA, */
/* MASK, etc.) */
pt->pt_r_fifo = base + ICC_FIFO;
pt->pt_r_ista = base + ICC_ISTA;
pt->pt_r_mask = base + ICC_MASK;
pt->pt_r_star = base + ICC_STAR;
pt->pt_r_cmdr = base + ICC_CMDR;
pt->pt_r_mode = base + ICC_MODE;
pt->pt_r_timr = base + ICC_TIMR;
pt->pt_r_exir = base + ICC_EXIR;
pt->pt_r_xad1 = base + ICC_XAD1;
pt->pt_r_xad2 = base + ICC_XAD2;
pt->pt_r_sap1 = base + ICC_SAP1;
pt->pt_r_sap2 = base + ICC_SAP2;
pt->pt_r_rsta = base + ICC_RSTA;
pt->pt_r_tei1 = base + ICC_TEI1;
pt->pt_r_tei2 = base + ICC_TEI2;
pt->pt_r_rhcr = base + ICC_RHCR;
pt->pt_r_spcr = base + ICC_SPCR;
pt->pt_r_stcr = base + ICC_STCR;
pt->pt_r_cixr = base + ICC_CIXR; /* = CIX0/CIR0 in later versions */
pt->pt_r_monr = base + ICC_MONR; /* = MOX0/MOR0 in later versions */
pt->pt_r_adfr = base + ICC_ADFR; /* = ADF1 in later versions */
pt->pt_r_rbcl = base + ICC_RFBC; /* = RBCL in later version */
pt->pt_r_rbch = base + ICC_RBCH;
pt->pt_r_mox1 = base + ICC_MOX1;
pt->pt_r_mocr = base + ICC_MOCR; /* = MOSR (read access) */
pt->pt_r_cix1 = base + ICC_CIX1; /* CIX1 and CIR1 register */
pt->pt_r_adf2 = base + ICC_ADF2;
pt->pt_r_rfbc = base + ICC_RFBC;
pt->pt_r_sfcr = base + ICC_SFCR;
pt->pt_r_sscx = base + ICC_SSGX;
pt->pt_r_sqxr = base + ISAC_SQXR; /* S/Q channel transmit and */
/* receive register */
/* STAR2 register */
pt->pt_r_star2 = base + ICC_STR2;
DISABLE_TREC_STATUS_CHECK ();
}
/***************************************************************************/
/* */
/* Function : InitLay2_ICC () */
/* Parameters: */
/* */
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/* ’pei’ 0x00 D-channel controller */
/* 0x40 B-channel controller (A) */
/* 0x80 B-channel controller (B) */
/* */
/* ’modulo’ 0 modulo 8 operation */
/* 1 modulo 128 operation */
/* */
/* ’mode’ operating mode. (automode, non automode, etc.) */
/* */
/* ’tim_mode’ value for the TIMR register (valid in auto mode only) */
/* refer to the description of that register in the */
/* data sheets. */
/* */
/* Purpose: Initialization of an ICCs (ISAC-..) HDLC controller part. */
/* After execution of InitLay2_ICC, the TEI values for */
/* the Broadcast Link are programmed. */
/* */
/* Note: No HDLC controller reset is done. */
/* Only two byte address fields are supported */
/* */
/* If the ICC (ISAC) is reprogrammed from AUTOMODE to NON - AUTOMODE */
/* the successful transmission and acknowledgement of an I-frame */
/* currently sent is not assured. */
/* Switching from AUTOMODE to NON AUTOMODE causes an I frame to be */
/* transmitted completely by the ICC. But the transmit acknowledge */
/* (XPR interrupt) in NON AUTOMODE only indicates that the ICC has */
/* sent the frame out of its XFIFO. It indicates not the successful */
/* transmission of the I-frame as it is in AUTOMODE (timer super- */
/* vision, polling for acknowledge frames)! */
/* Therefore if an I-frame is outstanding and the mode is changed */
/* from AUTOMODE to NON-AUTOMODE MISSING_ACKNOWLEDGE is called to */
/* generate a warning message. */
/* MISSING_ACKNOWLEDGE is also called if ’timer recovery’ status */
/* (TREC) or ’waiting for acknowledge (WFA)’ is indicated. */
/* */
/***************************************************************************/
EXPORT int
InitLay2_ICC (pei, modulo, mode, tim_mode)
BYTE pei, modulo, mode, tim_mode;
{
BYTE mode_reg;
register PEITAB *pt;
if (!(pt = GetPeitab_BASIC (pei))) /* request pointer to the */
/* corresponding PEITAB table */
/* element */
return (ACK_NOT_SUPPORTED);
if (modulo != 0 && modulo != 1)
return (ACK_WRONG_PARM);
outp (pt->pt_r_mask, 0xFF); /* no interrupts during init. */
mode_reg = inp (pt->pt_r_mode) & (MODE_HMD2 | MODE_HMD1 | MODE_HMD0);
switch (mode) /* select OPERATING MODE */
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{ /* ******************* */
case PT_MD_AUTO: /* HDLC AUTO MODE */
/* full address recognition, */
/* internal timer mode, receiver */
/* active, 2 bytes address fields */
/* are selected. */
mode_reg |= (MODE_TMD | MODE_RAC | MODE_ADM);
outp (pt->pt_r_timr, tim_mode);
break;
case PT_MD_NON_AUTO: /* HDLC NON AUTO MODE */
/* full address recognition, */
/* receiver active, 2 byte address */
/* fields */
mode_reg |= (MODE_MDS0 | MODE_RAC | MODE_ADM);
if (((pt->pt_op_mode == PT_MD_AUTO) &&
(pt->pt_state & PT_TX_ACTIVE) && (pt->pt_tx_frame == PT_FR_I))
|| (inp(pt->pt_r_star2) & (STAR2_TREC | STAR2_WFA)))
{
MISSING_ACKNOWLEDGE (pei);
ResetHDLC_ICC (pei);
}
outp (pt->pt_r_timr, 0);
break;
case PT_MD_TRANSP: /* TRANSPARENT MODE */
/* SAPI-address (high-byte) */
/* recognition */
mode_reg |= (MODE_MDS1 | MODE_MDS0 | MODE_RAC | MODE_ADM);
break;
case PT_MD_EXT_TRANSP: /* EXTENDED TRANSPARENT MODE */
case PT_MD_CLEAR_EXT: /* as well as clear mode */
/* no address recognition */
mode_reg |= (MODE_MDS1 | MODE_MDS0 | MODE_RAC);
break;
default:
outp (pt->pt_r_mask, 0x00);
return (ACK_WRONG_PARM);
}
pt->pt_op_mode = mode; /* save MODE register settings */
/* modulo: 1 (mod 128); 0 (mod 8) */
outp (pt->pt_r_sap2, (BYTE) (modulo ? 0x02 : 0x00));
outp (pt->pt_r_tei2, 0xFF);
if (modulo)
pt->pt_state |= PT_M128;
else
pt->pt_state &= ~PT_M128;
outp (pt->pt_r_mode, mode_reg);
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outp (pt->pt_r_mask, 0x00);
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: StoreTEI_ICC () */
/* Parms : ’pei’, ’tei’ and ’reg2’ */
/* purpose : program TEI in register TEI1 (reg2 = 0) or TEI2 (reg2 = 0) */
/* */
/***************************************************************************/
EXPORT int
StoreTEI_ICC (pei, tei, reg2)
BYTE pei, tei, reg2;
{
register PEITAB *pt;
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
if (reg2 == 1) /* store TEI in register TEI2 */
outp (pt->pt_r_tei2, tei);
else
{ /* store TEI in register TEI1 */
outp (pt->pt_r_xad2, tei);
outp (pt->pt_r_tei1, tei);
}
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: StoreSAPI_ICC () */
/* Parms : pei, sapi, reg2 */
/* purpose : store SAPI in register SAPI1 (reg2 = 0) or SAPI2 */
/* (reg2 = 0) */
/* */
/***************************************************************************/
EXPORT int
StoreSAPI_ICC (pei, sapi, reg2)
BYTE pei, sapi, reg2;
{
register PEITAB *pt;
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
sapi &= ~0x03;
if (reg2 == 1) /* store SAPI in SAP2 */
outp (pt->pt_r_sap2, sapi | ((pt->pt_state & PT_M128) ? 0x02 : 0x00));
else
{ /* store SAPI in SAP1 */
outp (pt->pt_r_xad1, sapi);
if ((pt->pt_ModulMode == PT_MM_NT) || (pt->pt_ModulMode == PT_MM_LT_S))
sapi |= 0x02;
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outp (pt->pt_r_sap1, sapi);
}
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: RecReady_ICC () */
/* Parms : pei, ready */
/* purpose : set HDLC receiver ready (’ready’= 1) */
/* not ready (’ready’= 0) */
/* To be used in auto mode only */
/* */
/***************************************************************************/
EXPORT int
RecReady_ICC (pei, ready)
BYTE pei, ready;
{
register PEITAB *pt;
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
outp (pt->pt_r_cmdr, (BYTE) (ready ? 0x00 : CMDR_RNR));
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: ResetHDLC_ICC () */
/* Parms : pei */
/* purpose : reset HDLC controller */
/* */
/***************************************************************************/
EXPORT int
ResetHDLC_ICC (pei)
BYTE pei;
{
register PEITAB *pt;
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
outp (pt->pt_r_mask, 0xFF);
/* clear receive and transmit */
/* paths, i.e. clear the status */
/* variables indicating any */
/* transmission or reception of */
/* frames and release the MMU */
/* buffers */
FREE_TX_PATH (pt->pt_pei);
if (pt->pt_rx_start)
{
MMU_free (pt->pt_rx_start);
pt->pt_rx_start = NULL_PTR;
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pt->pt_state &= ~PT_REC_ACTIVE;
pt->pt_rx_frame = 0x00;
pt->pt_rx_cnt = 0;
}
pt->pt_state &= ~PT_REC_ACTIVE;
/* set the reset flag in the state */
/* variable. This allows the */
/* interrupt service routine to */
/* react correctly on the following */
/* XPR interrupt */
pt->pt_state |= PT_HDLC_RESET;
/* the reset commands: */
/* - receive message complete (RME) */
/* - reset hdlc receiver (RHR) */
/* - transmitter reset (XRES)*/
outp (pt->pt_r_cmdr, CMDR_RMC | CMDR_RHR | CMDR_XRES);
if (pt->pt_op_mode == PT_MD_AUTO) /* write TIMR register to stop the */
/* internal timer in automode */
outp (pt->pt_r_timr, inp(pt->pt_r_timr));
outp (pt->pt_r_mask, 0); /* now allow all interrupts again */
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: SendFrame_ICC () */
/* Parms : ’pei’ */
/* ’frame_type’ specifying the frame */
/* ’cnt’ number of bytes to send */
/* ’frame_ptr’ pointer to the data bytes */
/* */
/* purpose : Initiate transmission of HDLC frames ( S, U, I, UI ) */
/* */
/***************************************************************************/
EXPORT int
SendFrame_ICC (pei, frame_type, cnt, frame_ptr)
BYTE pei, frame_type;
WORD cnt;
FPTR frame_ptr;
{
register PEITAB *pt;
BYTE cmd;
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
/* return if XFIFO is not write */
/* enable */
if (!(inp (pt->pt_r_star) & 0x40))
return (ACK_ACCESS_FAULT);
/* return if transmit path still */
/* blocked and not in automode */
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if (pt->pt_state & PT_TX_ACTIVE && pt->pt_op_mode != PT_MD_AUTO)
return (ACK_ACCESS_FAULT);
if (pt->pt_op_mode == PT_MD_AUTO)
{
/* it is not allowed to send an I */
/* frame in the timer recovery */
/* or in waiting_for_acknowledge */
/* status */
if (inp(pt->pt_r_star2) & (STAR2_TREC | STAR2_WFA))
if (frame_type == PT_FR_I)
return (ACK_ACCESS_FAULT);
if (inp(pt->pt_r_star2) & STAR2_WFA)
if (pt->pt_state & PT_TX_MMU_FREE)
{
MMU_free (pt->pt_tx_start);
pt->pt_state &= ~PT_TX_MMU_FREE;
}
}
pt->pt_state |= PT_TX_ACTIVE; /* transmitter is active */
pt->pt_tx_start = frame_ptr; /* store data frame pointer */
pt->pt_tx_frame = frame_type; /* and frame type */
if (cnt <= 32)
{
/* if the number of bytes is <=32 */
/* the frame can be shifted */
/* completely into the XFIFO */
STRING_OUT (frame_ptr, pt->pt_r_fifo, cnt);
pt->pt_tx_cnt = 0;
}
else
{
/* if the number of bytes is */
/* greater 32 the first 32 are */
/* shifted into the XFIFO, the */
/* remaining are sent later */
/* (interrupt service routine) */
STRING_OUT (frame_ptr, pt->pt_r_fifo, 32);
pt->pt_tx_cnt = cnt - 32;
pt->pt_tx_curr = frame_ptr + 32;
}
/* compute the command byte for */
/* the CMDR register: */
/* in automode the ’transmit I */
/* frame’ command must be used */
/* when it is an HDLC I frame. */
/* The ’transmit transparent */
/* frame’ command must be used in */
/* all other cases */
if (pt->pt_op_mode == PT_MD_AUTO)
{
cmd = (pt->pt_tx_frame == PT_FR_I) ? CMDR_XIF : CMDR_XTF;
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if (inp (pt->pt_r_star) & CMDR_RNR)
cmd |= CMDR_RNR;
}
else
cmd = CMDR_XTF;
/* When the frame fits completely */
/* into the XFIFO the XME command */
/* must be given */
if (!pt->pt_tx_cnt)
cmd |= CMDR_XME;
outp (pt->pt_r_cmdr, cmd); /* now output the command byte to */
/* the CMDR register */
/* UI frame sent while waiting for */
/* ackowledge in automode (an ID */
/* check response UI frame) */
/* The flag is checked by the */
/* interrupt service routine when */
/* handling the next XPR interrupt. */
if (inp(pt->pt_r_star2) & STAR2_WFA && pt->pt_op_mode == PT_MD_AUTO
&& frame_type == PT_FR_UI)
pt->pt_state |= UI_SENT_WHILE_WAITING_FOR_ACK;
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: Loop_ICC () */
/* Parms : ’pei’ */
/* ’on’ 1 -> test-loop on */
/* 0 -> test-loop off */
/* purpose: switch testloop at the IOM interface on/off */
/* */
/***************************************************************************/
EXPORT int
Loop_ICC (pei, on)
BYTE pei;
BOOLEAN on;
{
PEITAB *pt_dch;
BYTE r_spcr;
register PEITAB *pt;
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
pt_dch = GetPeitab_BASIC (0);
if (on) /* Loop ON */
{
pt->pt_state |= PT_LOOP;
/* enable clocks in TE mode */
if (pt->pt_ModulMode == PT_MM_TE)
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{
/* dummy value in the cixr register */
/* prevents a false interpretation of*/
/* the incoming (looped) C/I channel */
if (EnableClk_BASIC (pt_dch))
outp (pt_dch->pt_r_cixr, 0x6F);
}
r_spcr = inp (pt->pt_r_spcr);
outp (pt->pt_r_spcr, r_spcr | SPCR_TPL);
}
else /* Loop OFF */
{
r_spcr = inp (pt->pt_r_spcr) & ~SPCR_TPL;
outp (pt->pt_r_spcr, r_spcr);
pt->pt_state &= ~PT_LOOP;
}
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: SwitchB_ICC () */
/* purpose : switch the B-channels in IOM1 configurations */
/* to the SSI or SLD interface or back to network */
/* */
/***************************************************************************/
EXPORT int
SwitchB_ICC (pei, chan_ctrl, sip_act)
BYTE pei, chan_ctrl;
BOOLEAN sip_act;
{
register PEITAB *pt;
BYTE r_spcr;
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
if (chan_ctrl > 0x0F)
return (ACK_WRONG_PARM);
if (!(pt->pt_state & PT_IOM2))
{
r_spcr = inp (pt->pt_r_spcr) & 0xF0;
if (sip_act) /* activate SIP ? */
r_spcr |= SPCR_SAC; /* yes: set SAC bit */
else
r_spcr &= ~SPCR_SAC; /* no: clear SAC bit */
outp (pt->pt_r_spcr, r_spcr | chan_ctrl);
}
return (ACK_DONE);
}
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/* *** The interrupt service routines *** */
/************************************************************************/
/***************************************************************************/
/* */
/* Function: Int_ICC () */
/* Parms :’pt’ pointer to the corresponding PEITAB-table element */
/* purpose : handle ICC (ISAC-S, ISAC-P) interrupts */
/* Int_ICC is called from IntServ_BASIC in basic_l2.c which */
/* is SIPB system specific. */
/* */
/***************************************************************************/
EXPORT void
Int_ICC (pt)
register PEITAB *pt;
{
WORD cnt;
BYTE exir, cmd;
register BYTE ista;
if (!(ista = inp (pt->pt_r_ista)))
return;
exir = inp (pt->pt_r_exir);
/* XPR interrupt */
/* ============= */
/* the XPR interrupt indicates */
/* that the XFIFO is ready for new */
/* data bytes. */
/* Reasons: */
/* - HDLC controller reset */
/* (CMDR:XRES) */
/* - data transmission finished */
if ((ista & ISTA_XPR) && !(ista & ISTA_TIN) && !(exir & EXIR_PCE))
{
/* transmit byte count is 0 */
/* ------------------------ */
if ((cnt = pt->pt_tx_cnt) == 0)
{
/* HDLC controller reset command */
/* given previously ? */
/* ----------------------------- */
/* do nothing when it was a HDLC */
/* controller reset only the */
/* indicating flag must be cleared */
if (pt->pt_state & PT_HDLC_RESET)
pt->pt_state &= ~PT_HDLC_RESET;
else
{
/* XPR was generated because the */
/* last transmission is finished */
/* ------------------------------ */
/* AUTOMODE operation ? */
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if (pt->pt_op_mode == PT_MD_AUTO)
{
/* UI frame sent while waiting for */
/* I frame acknowledge ? */
if (pt->pt_state & UI_SENT_WHILE_WAITING_FOR_ACK)
{
/* the UI frame was sent out if the */
/* XFIFO is empty (write enable) */
if (inp(pt->pt_r_star) & STAR_XFW)
TX_ACKNOWLEDGE (pt->pt_pei, pt->pt_tx_frame);
pt->pt_state &= ~UI_SENT_WHILE_WAITING_FOR_ACK;
/* if we are in timer recovery */
/* status the TREC status check */
/* procedure is activated. The */
/* transmit acknowledge for the I */
/* frame must not be generated !!! */
if (inp (pt->pt_r_star2) & STAR2_TREC)
ENABLE_TREC_STATUS_CHECK ();
else
TX_ACKNOWLEDGE (pt->pt_pei, (BYTE) PT_FR_I);
}
else
{
/* if we are in timer recovery */
/* status and the last frame was an */
/* I frame the TREC status check */
/* procedure is activated. */
/* If not an transmit acknowledge */
/* is generated */
if (pt->pt_tx_frame == PT_FR_I &&
(inp (pt->pt_r_star2) & STAR2_TREC))
ENABLE_TREC_STATUS_CHECK ();
else
TX_ACKNOWLEDGE (pt->pt_pei, pt->pt_tx_frame);
}
}
else
/* In all other operating modes */
/* (non automode, transparent mode, */
/* ...) the transmit acknowledge */
/* can be generated at once. */
TX_ACKNOWLEDGE (pt->pt_pei, pt->pt_tx_frame);
/* transmit byte count and status */
/* flag are reset and any */
/* MMU buffer used for temporary */
/* transmit data storage is */
/* released if necessary */
pt->pt_tx_cnt = 0;
pt->pt_state &= ~PT_TX_ACTIVE;
if (pt->pt_state & PT_TX_MMU_FREE)
{
MMU_free (pt->pt_tx_start);
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pt->pt_state &= ~PT_TX_MMU_FREE;
}
}
}
else
{ /* transmit count is not 0 */
/* more data to be sent ! */
/* ------------------------ */
if (pt->pt_op_mode == PT_MD_AUTO)
cmd = (pt->pt_tx_frame ? CMDR_XTF : CMDR_XIF) |
(inp(pt->pt_r_star) & CMDR_RNR);
else
cmd = CMDR_XTF;
/* less than 32 bytes left ? */
if (pt->pt_tx_cnt <= 32)
{
/* shift all bytes into the XFIFO */
/* and give XME command */
STRING_OUT (pt->pt_tx_curr, pt->pt_r_fifo, cnt);
pt->pt_tx_cnt = 0;
outp (pt->pt_r_cmdr, cmd | CMDR_XME);
}
else
{ /* more than 32 bytes are left to */
/* be sent; write 32 into the XFIFO */
STRING_OUT (pt->pt_tx_curr, pt->pt_r_fifo, 32);
outp (pt->pt_r_cmdr, cmd); /* give the transmit command, */
pt->pt_tx_curr += 32; /* update current buffer pointer */
pt->pt_tx_cnt -= 32; /* and counter of remaining bytes */
}
}
}
if (ista & ISTA_TIN) /* TIN interrupt */
{ /* ============= */
/* ResetHDLC_ICC (pt->pt_pei); */
DISABLE_TREC_STATUS_CHECK ();
TIN_ERROR (pt->pt_pei);
}
/* HDLC receiver interrupt ? */
/* ========================= */
/* (receive pool full or receive */
/* message end and not PCE and not */
/* TIN) */
if ((ista & (ISTA_RPF | ISTA_RME))
&& !(exir & EXIR_PCE) && !(ista & ISTA_TIN))
RX_ICC (ista & ISTA_RPF, pt);
/* status change of the remote */
/* station’s receiver */
/* (i.e. RR or RNR received). */
/* The status can be determined by */
/* reading the RRNR bit of */
/* register STAR */
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if (ista & ISTA_RSC)
{
if (inp (pt->pt_r_star) & 0x10)
PEER_REC_BUSY (pt->pt_pei); /* peer receiver busy */
else
PEER_REC_READY (pt->pt_pei); /* peer receiver ready */
}
/* B (2.x) versions of L1 device */
/* controllers can’t prevent CIC bit*/
/* being set even when masked. */
/* CIC interrupt ? (layer 1 device */
/* status change) */
if ((ista & ISTA_CIC) && !interrupt_act)
IntLay1_BASIC (pt);
if (ista & ISTA_EXI) /* Extended interrupt ? */
{ /* ================== */
/* transmit message repeat int. ? */
if ((exir & EXIR_XMR) && !(exir & EXIR_PCE) && !(ista & ISTA_TIN))
{
XMR_ERROR (pt->pt_pei);
FREE_TX_PATH (pt->pt_pei);
}
if (exir & EXIR_XDU) /* transmit data underrun ? */
{
TX_DATA_UNDERRUN (pt->pt_pei);
FREE_TX_PATH (pt->pt_pei);
}
if (exir & EXIR_PCE) /* protocol error interrupt ? */
{
/* ResetHDLC_ICC (pt->pt_pei); */
PROTOCOL_ERROR (pt->pt_pei);
}
if (exir & EXIR_RFO) /* receive frame overflow int. ? */
{
MMU_free (pt->pt_rx_start);
pt->pt_rx_start = NULL_PTR;
pt->pt_state &= ~PT_REC_ACTIVE;
pt->pt_rx_frame = 0;
pt->pt_rx_cnt = 0;
REC_FRAME_OVERFLOW (pt->pt_pei);
}
if (exir & EXIR_MOR) /* MON channel interrupt ? */
if (interrupt_act)
IntMon_MOFC ();
else
Wr_IntMon_MOFC ();
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}
}
/***************************************************************************/
/* */
/* Function: RX_ICC () */
/* Parms : ’pt’ pointer to the assigned PEITAB array element */
/* ’rpf’ = 1 if RPF interrupt */
/* purpose : handle interrupts generated by the receiver of an */
/* ICC (ISAC-S, ISAC-P) */
/* */
/***************************************************************************/
LOCAL void
RX_ICC (rpf, pt)
BOOLEAN rpf;
register PEITAB *pt;
{
WORD RecCnt, ctrl;
FPTR ptr;
BYTE pei = pt->pt_pei;
BYTE rsta, tei, sapi, frame_status = VALID;
BOOLEAN Two, AutoM, CR_of_I_valid = TRUE;
/* RPF interrupt: */
/* 32 bytes of a frame longer than */
/* 32 bytes have been received */
/* and are now available in the */
/* RFIFO. */
/* The message is not complete. */
if (rpf)
RecCnt = 32;
else
{
/* RME interrupt: */
/* Receive message end. The RFIFO */
/* contains a complete frame */
/* (length <= 32 byte) or the last */
/* bytes or a frame (length > 32) */
/* ================================ */
/* read byte count register(s) to */
/* get the number of currently */
/* received bytes */
/* please note that ICC / ISAC-S */
/* version Axx had only one byte */
/* count register !!! */
if (pt->pt_device == PT_ICC || pt->pt_device == PT_ISAC_S)
RecCnt = (BYTE) inp (pt->pt_r_rfbc);
else
RecCnt = (WORD) inp (pt->pt_r_rbcl) |
(WORD) (inp (pt->pt_r_rbch) & 0x0F) << 8;
if (RecCnt && !(RecCnt &= 0x1F))
RecCnt = 32;
}
/* ’RecCnt’ now contains the number */
/* of bytes actually received */
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Low Level Controller
/* was receiver active before or is */
/* the RPF/RME for a new incoming */
/* frame ? */
if (!(pt->pt_state & PT_REC_ACTIVE))
{
if (RecCnt > 0)
{
if (rpf)
pt->pt_rx_curr = pt->pt_rx_start = MMU_req (266);
else
pt->pt_rx_curr = pt->pt_rx_start = MMU_req (38);
if (pt->pt_rx_start == NULL_PTR)
{
MMU_ERROR (pei);
pt->pt_rx_frame = PT_FR_NO_MEMORY;
}
}
pt->pt_state |= PT_REC_ACTIVE;
pt->pt_rx_cnt = RecCnt;
}
else
/* if data has been already */
/* received only the receive byte */
/* counter must be updated */
pt->pt_rx_cnt += RecCnt;
/* automode and frame greater */
/* 260 byte and automode link ? */
if (pt->pt_op_mode == PT_MD_AUTO && pt->pt_rx_cnt > 260 &&
((inp (pt->pt_r_rsta) & 0x0D) == 9))
{
pt->pt_rx_frame = PT_FR_OVERFLOW;
/* ICC B4, ISAC-S B3 */
/* reset the receiver if incoming */
/* frame exceeds 528 byte I field */
/* length -> */
/* unbounded frame */
if (rpf && pt->pt_rx_cnt > 528)
{
outp (pt->pt_r_cmdr, CMDR_RHR);
MMU_free (pt->pt_rx_start);
pt->pt_rx_start = NULL_PTR;
pt->pt_state &= ~PT_REC_ACTIVE;
pt->pt_rx_frame = 0x00;
pt->pt_rx_cnt = 0;
N201_ERROR (pei);
return;
}
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Low Level Controller
}
else
if (pt->pt_rx_cnt > 266)
pt->pt_rx_frame = PT_FR_OVERFLOW;
/* read the bytes from the RFIFO */
/* if no error was detected */
if (pt->pt_rx_frame < PT_FR_ERROR)
{
if (RecCnt)
{
STRING_IN (pt->pt_rx_curr, pt->pt_r_fifo, RecCnt);
pt->pt_rx_curr += RecCnt; /* update buffer pointer */
} /* it points to the next free */
/* location in the buffer */
}
if (rpf) /* return when it was a RPF int. */
{
outp (pt->pt_r_cmdr, CMDR_RMC | (inp (pt->pt_r_star) & CMDR_RNR));
return;
}
/* RME interrupt handling !!! */
/* ========================== */
/* the receive status byte is in */
/* register RSTA */
rsta = inp (pt->pt_r_rsta);
/************************************************************************/
/* It follows a scanning section to get some information about the */
/* received data: */
/* - Performed address recognition */
/* - SAPI (’sapi’), TEI (’tei’) and control field byte(s) (’ctrl’) */
/* as well as the type of frame (HDLC U, UI, S or I frame) are */
/* determined. */
/* In addition the length of a frame is checked. */
/************************************************************************/
/* set ’pei’ according to performed */
/* address recognition */
pei |= ((rsta & 0x0C) >> 1) | (rsta & 0x01);
AutoM = FALSE;
tei = 0;
sapi = rsta & 0x02; /* get the C/R bit value */
ptr = pt->pt_rx_start;
/* now get additional information */
/* (TEI, SAPI, control field) */
switch (pt->pt_op_mode) /* It depends on the selected */
/* operating mode */
{
case PT_MD_CLEAR_EXT: /* no address recognition, */
/* no firmware interaction */
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pt->pt_rx_frame = PT_FR_TR;
ctrl = 0x00L;
break;
case PT_MD_EXT_TRANSP: /* no address recognition, SAPI */
/* and TEI are the first two bytes */
/* of data */
if (pt->pt_rx_cnt > 0)
pt->pt_rx_cnt--;
sapi = *ptr++;
case PT_MD_TRANSP: /* high byte address recognition, */
/* TEI is the first byte read */
if (pt->pt_rx_cnt < 2)
frame_status = MUTILATED;
else
pt->pt_rx_cnt -= 2;
/* read TEI and control field */
tei = *ptr++;
ctrl = (WORD) *ptr++;
if (pt->pt_op_mode == PT_MD_TRANSP)
pei |= 0x20;
else
pei |= 0x30;
break;
case PT_MD_AUTO: /* full address recognition in */
case PT_MD_NON_AUTO: /* AUTO/nonAUTOMODE read only the */
/* HDLC control field information */
if (pt->pt_op_mode == PT_MD_AUTO)
/* AUTOMODE link ??? */
AutoM = ((rsta & 0x0D) == 0x09) ? TRUE : FALSE;
if (!AutoM)
pei |= 0x10;
/* the (first byte of the) control */
/* field is in register RHCR */
ctrl = (WORD) inp (pt->pt_r_rhcr);
break;
}
switch (ctrl & 0x03) /* determine the frame type */
{ /* ======================== */
case 0x3: /* *** HDLC U frame ** */
Two = FALSE; /* one byte control field ! */
if (pt->pt_rx_cnt == 0)
{
pt->pt_rx_frame = PT_FR_U;
break;
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Low Level Controller
}
else /* as can be seen here U frames */
pt->pt_rx_frame = PT_FR_UI;/* with I field are always treated */
/* as UI frames regardless whether */
/* it’s an real UI frame or an */
/* erroneous (= too long) U frame */
break;
case 0x1: /* *** HDLC S-Frame ** */
/* two byte control field ? */
if ((Two = (pt->pt_state & PT_M128)))
{
ctrl <<= 8;
ctrl |= (WORD) *ptr++;
if (pt->pt_rx_cnt > 0)
pt->pt_rx_cnt--;
else /* Second byte of the two byte */
/* control field is missing ! */
frame_status = MUTILATED;
}
if (pt->pt_rx_cnt > 0) /* S frame with I-field ! */
frame_status = TOO_LONG;
pt->pt_rx_frame = PT_FR_S;
break;
case 0x2: /* *** HDLC I frame ** */
case 0x0:
/* no address recognition */
if (pt->pt_op_mode == PT_MD_CLEAR_EXT)
{
pt->pt_rx_frame = PT_FR_TR;
break;
}
Two = (pt->pt_state & PT_M128);
pt->pt_rx_frame = PT_FR_I;
/* C/R bit of received I frame */
/* valid (=1) in TE configuration ? */
/* If ’CR_of_I_valid’ is FALSE the */
/* automatic acknowledge of an */
/* I frame in Automode is */
/* prevented! A protocol software */
/* will receive the PROTOCOL_ERROR */
/* message and re-establish the */
/* link. */
if (AutoM && !(sapi & 0x02) && (pt->pt_ModulMode == PT_MM_TE))
CR_of_I_valid = FALSE;
if (AutoM)
break;
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Low Level Controller
if (Two) /* two byte control field ? */
{
if (pt->pt_rx_cnt == 0)
frame_status = MUTILATED;
if (pt->pt_rx_cnt > 0)
pt->pt_rx_cnt--;
ctrl <<= 8;
ctrl |= (WORD) *ptr++;
}
break;
}
if (pt->pt_rx_cnt > 260) /* I part greater than 260 ? */
{
pt->pt_rx_frame = PT_FR_OVERFLOW;
N201_ERROR(pei);
/* must reset the controller */
outp (pt->pt_r_cmdr, CMDR_RMC | CMDR_RHR | CMDR_XRES);
outp (pt->pt_r_timr, inp(pt->pt_r_timr));
pt->pt_state |= PT_HDLC_RESET;
FREE_TX_PATH (pt->pt_pei);
}
else
if (!CR_of_I_valid) /* C/R of I frame invalid in TE ? */
{ /* prevent acknowledging S-frame */
/* beeing sent and create */
/* PROTOCOL_ERROR message. */
pt->pt_rx_frame = PT_FR_FAULT;
PROTOCOL_ERROR (pt->pt_pei);
/* must reset the controller */
outp (pt->pt_r_cmdr, CMDR_RMC | CMDR_RHR | CMDR_XRES);
outp (pt->pt_r_timr, inp(pt->pt_r_timr));
pt->pt_state |= PT_HDLC_RESET;
FREE_TX_PATH (pt->pt_pei);
}
else /* enter ’RMC’ command if not */
outp (pt->pt_r_cmdr, CMDR_RMC | (inp (pt->pt_r_star) & CMDR_RNR));
/************************************************************************/
/* */
/* Now all information about the received frame is available: */
/* - performed address recognition or TEI and SAPI values. */
/* - HDLC control field */
/* - type of frame (HDLC U, UI, S, I frame). */
/* - info about the validity of the frame */
/* */
/************************************************************************/
if (rsta = (rsta & (RSTA_RDO | RSTA_CRC | RSTA_RAB)) ^RSTA_CRC)
pt->pt_rx_frame = PT_FR_FAULT;
switch (pt->pt_rx_frame)
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Low Level Controller
{
case PT_FR_FAULT:
if (rsta & RSTA_RDO)
REC_DATA_OVERFLOW (pei);
if (rsta & RSTA_RAB)
REC_ABORTED (pei);
if (rsta & RSTA_CRC) /* CRC has already been inverted */
CRC_ERROR (pei);
break;
case PT_FR_S: /* HDLC S frame ? */
/* ============== */
/* extra parameter for 1 byte */
/* address field set to FALSE */
Decode_S_Frame_BASIC (pei, sapi, tei, ctrl, frame_status,
((pt->pt_state & PT_M128) ? 0x01 : 0x00), FALSE);
MMU_free (pt->pt_rx_start);
break;
case PT_FR_U: /* HDLC U frame ? */
/* ============== */
/* extra parameter for 1 byte */
/* address field set to FALSE */
Decode_U_Frame_BASIC (pei, sapi, tei, (BYTE) ctrl, FALSE);
MMU_free (pt->pt_rx_start);
break;
case PT_FR_UI: /* HDLC UI or I frame ? */
case PT_FR_I: /* ==================== */
case PT_FR_TR: /* ==================== */
if (pt->pt_rx_frame < PT_FR_ERROR)
{
FRAME_PASS fp;
fp.mmu_buff = pt->pt_rx_start;
fp.start_of_i_data = ptr;
fp.i_data_cnt = pt->pt_rx_cnt;
fp.Two_byte_cf = Two;
fp.ctrl_field = ctrl;
fp.pei = pei;
fp.frame = pt->pt_rx_frame | frame_status;
fp.sapi = sapi;
fp.tei = tei;
/* transfer the frame to the ’long */
/* frame queue’ */
PassLongFrame_BASIC (&fp);
}
break;
} /* end of ’switch (pt->pt_rx_frame)’ ------------------------------- */
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Low Level Controller
/* release the data buffer if the */
/* frame reception or the frame */
/* were erroneous */
if (pt->pt_rx_frame >= PT_FR_ERROR)
MMU_free (pt->pt_rx_start);
pt->pt_rx_start = NULL_PTR;
pt->pt_state &= ~PT_REC_ACTIVE;
pt->pt_rx_frame = 0x00;
pt->pt_rx_cnt = 0;
}
/***************************************************************************/
/* */
/* Function: Check_TREC_status_ICC () */
/* Parms : */
/* purpose : called periodically if timer recovery status was detected */
/* during previous XPR interrupt handing. A */
/* transmit-acknowledge for I frame is generated if the TREC */
/* status is left. */
/* */
/***************************************************************************/
EXPORT void
Check_TREC_status_ICC ()
{
register PEITAB *pt;
if (!(pt = GetPeitab_BASIC (0)))
return;
outp (pt->pt_r_mask, ~MASK_TIN); /* allow only TIN interrupts */
/* timer recovery status left ? */
if (!(inp(pt->pt_r_star2) & STAR2_TREC))
{
if (inp(pt->pt_r_ista) & ISTA_TIN)
{
ResetHDLC_ICC (pt->pt_pei);
TIN_ERROR (pt->pt_pei);
}
else
/* generate a transmit acknowledge */
/* I frame if there was no TIN */
/* interrupt */
TX_ACKNOWLEDGE (pt->pt_pei, (BYTE) PT_FR_I);
DISABLE_TREC_STATUS_CHECK ();
}
outp (pt->pt_r_mask, 0x00);
}
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Low Level Controller
/***************************************************************************/
/* */
/* SIEMENS ISDN-Userboard (c) 1987-1993 */
/* ====================== */
/* */
/* Firmware: driver functions for SBC / L1 part of ISAC-S */
/* File : sbc.c */
/* */
/***************************************************************************/
/* Include Files */
/* ============= */
#include "def.h"
#include "basic.h"
#include "message.h"
/* CI codes for SBC and ISAC-S PM */
/*********************************************************/
#define CI_PU (BYTE)0x1C /* 0111 PU indication */
#define CI_TIM (BYTE)0x00 /* 0000 timing requested */
#define CI_AI (BYTE)0x30 /* 1100 activation indication */
#define CI_AR (BYTE)0x20 /* 1000 activation request */
#define CI_DIU (BYTE)0x3C /* 1111 deactivation ind. upstream */
#define CI_DID (BYTE)0x3C /* 1111 deactivation ind. downst. */
#define CI_DR (BYTE)0x00 /* 0000 deactivation request */
#define CI_RS (BYTE)0x04 /* 0001 Reset */
#define CI_EI (BYTE)0x18 /* 0110 Error indicate downstream */
/* Imported Functions */
/* ================== */
/* from crt0.asm */
IMPORT WORD ENTERNOINT ();
IMPORT void LEAVENOINT ();
/* from basic00.c */
IMPORT PEITAB *GetPeitab_BASIC ();
/* Export Functions */
/* ================ */
EXPORT int InitL1_SBC ();
EXPORT int ActL1_SBC ();
EXPORT int ArlL1_SBC ();
EXPORT int DeaL1_SBC ();
EXPORT void IntL1_SBC ();
EXPORT int ResL1_SBC ();
EXPORT int EnaClk_SBC ();
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Low Level Controller
/* Variables */
/* ========= */
/* Function Declaration */
/* ==================== */
/***************************************************************************/
/* */
/* Function: EnaClk_SBC () */
/* Parms : pointer to PEITAB table element */
/* purpose : enable clocks for TE configurations */
/* */
/***************************************************************************/
EXPORT int
EnaClk_SBC (pt)
register PEITAB *pt;
{
unsigned int count, i = 0;
BYTE BitSet, spcr;
/* Test to see if clocks are */
/* actually there. Because the SBC */
/* after reset does not deactivate */
/* its clocks immediately we will */
/* make pretty sure that the clocks */
/* are there before we leave this */
/* routine */
BitSet = inp (pt->pt_r_star) & STAR_BVS;
count = 0;
/* we test to see if 6 changes in */
/* the STAR:BVS bit indicating the */
/* reception of at least 3 frames */
/* (6 B channels). If at any time */
/* we fail to find a bit change */
/* and the counter i reaches its */
/* maximum then we assume that */
/* clocks are no longer present */
for (i = 0; i < 500; i++)
if ((inp(pt->pt_r_star) & STAR_BVS) != BitSet)
{ /* Of course we have to reset our */
/* counter every time a bit change */
if (++count > 6) /* is observed to give the next */
return (FALSE); /* bit change the same amount of */
/* time in which to occur !!! */
i = 0;
BitSet = inp (pt->pt_r_star) & STAR_BVS;
}
/* the Bx versions reqire one edge */
/* at FSC. */
/* Otherwise the setting of the SPU */
/* has no effect (result: no clock) */
/* The IOM direction control bit */
/* IDC in the ADF1 (SQXR) register */
/* is set before and reset after */
/* the system is clocking */
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Low Level Controller
/* ICC Bx: IDC is in reg. ADF1 */
if (pt->pt_device == PT_ICC_B)
outp (pt->pt_r_adfr, 0x10);
/* ISAC-S Bx: IDC is in reg. SQXR */
if (pt->pt_device == PT_ISAC_S_B)
outp (pt->pt_r_sqxr, 0x80);
spcr = inp(pt->pt_r_spcr);
outp (pt->pt_r_spcr, spcr | SPCR_SPU);
if (pt->pt_state & PT_IOM2)
outp (pt->pt_r_cixr, CIXR_TBC | CI_TIM | 0x03);
else
outp (pt->pt_r_cixr, CIXR_TBC | CI_TIM);
/* wait for power up indication */
while ((inp(pt->pt_r_cixr) & CIR_MASK) != CI_PU)
if (++i > 1000)
break; /* time out */
outp (pt->pt_r_spcr, spcr);
/* now reset the IDC bit */
/* ICC Bx: IDC is in reg. ADF1 */
if (pt->pt_device == PT_ICC_B)
outp (pt->pt_r_adfr, 0x00);
/* ISAC-S Bx: IDC is in reg. SQXR */
if (pt->pt_device == PT_ISAC_S_B)
outp (pt->pt_r_sqxr, 0x00);
return (TRUE);
}
/***************************************************************************/
/* */
/* Function: InitL1_SBC () */
/* Parms : PEI value, mode of operation */
/* purpose : initialize an SBC controlling ICC / L1 part of an ISAC-S */
/* reset L1 to come to default state */
/* */
/***************************************************************************/
EXPORT int
InitL1_SBC (pei, mode_type)
BYTE pei, mode_type;
{
register PEITAB *pt;
BYTE r_mode;
/* return if the addressed device */
/* is not operational or not used */
/* for LAYER 1 control */
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
if (!(pt->pt_state & PT_L1_CTRL))
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Low Level Controller
return (ACK_NOT_SUPPORTED);
outp (pt->pt_r_mask, 0xFF);
/* compare the requested */
/* initialization mode with */
/* detected hardware configuration */
/* (’pt_ModulMode’) */
if (pt->pt_ModulMode != mode_type)
{
outp (pt->pt_r_mask, 0x00);
return (ACK_WRONG_MODUL_MODE);
}
/* timing mode 0 is used on the */
/* SIPB for TE and NTS configu- */
/* ration */
r_mode = inp (pt->pt_r_mode);
if (mode_type == PT_MM_TE)
outp (pt->pt_r_mode, (r_mode & ~(MODE_HMD2 | MODE_HMD1)) | MODE_HMD0);
else
outp (pt->pt_r_mode, r_mode & ~(MODE_HMD2 | MODE_HMD1 | MODE_HMD0));
if (pt->pt_state & PT_IOM2) /* IOM 2 mode ? */
{
outp (pt->pt_r_adf2, 0x80); /* program IOM2 mode in ICC/ISAC-S */
switch (mode_type)
{
case PT_MM_NT:
/* Changed to be terminal mode */
/* timing rather than SPCR_SPM */
outp (pt->pt_r_spcr, 0x00);
/* no terminal specific functions */
outp (pt->pt_r_stcr, 0x00);
outp (pt->pt_r_mode, (r_mode & ~(MODE_HMD2 | MODE_HMD0))
| MODE_HMD1);
break;
case PT_MM_TE:
outp (pt->pt_r_spcr, 0x00); /* terminal mode */
outp (pt->pt_r_stcr, 0x70); /* TIC bus address ’7’ */
/* no watchdog timer */
break;
}
}
else
{
outp (pt->pt_r_adf2, 0x00); /* program IOM2 mode in ICC/ISAC-S */
outp (pt->pt_r_stcr, 0x70); /* program TIC bus address */
}
outp (pt->pt_r_mask, 0x00);
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Low Level Controller
if (!ResL1_SBC (pt))
return (ACK_ACCESS_FAULT);
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: ActL1_SBC () */
/* Parms : PEI value */
/* purpose : establish L1 link (= activation) */
/* */
/***************************************************************************/
EXPORT int
ActL1_SBC (pei)
BYTE pei;
{
register PEITAB *pt;
/* return if the addressed device */
/* is not operational or not used */
/* for LAYER 1 control */
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
if (!(pt->pt_state & PT_L1_CTRL))
return (ACK_NOT_SUPPORTED);
/* the activation procedure is not */
/* done if the layer 1 link is */
/* already established. In that */
/* case only an activation */
/* indication message is generated */
if (((pt->pt_CI_rec = inp(pt->pt_r_cixr)) & CIR_MASK) != CI_AI)
{
if (pt->pt_ModulMode == PT_MM_TE)
EnaClk_SBC (pt);
if (pt->pt_state & PT_IOM2)
outp (pt->pt_r_cixr, CIXR_TBC | CI_AR | 0x03);
else
outp (pt->pt_r_cixr, CIXR_TBC | CI_AR);
return (ACK_DONE);
}
DECODE_L1_STATUS (pei, pt->pt_CI_rec);
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: ArlL1_SBC () */
/* Parms : PEI value */
/* purpose : activate local loop */
/* */
/***************************************************************************/
EXPORT int
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Low Level Controller
ArlL1_SBC (pei)
BYTE pei;
{
register PEITAB *pt;
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
if (pt->pt_ModulMode == PT_MM_TE)
EnaClk_SBC (pt);
if (pt->pt_state & PT_IOM2)
outp (pt->pt_r_cixr, 0x6B);
else
outp (pt->pt_r_cixr, 0x68);
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: DeaL1_SBC */
/* Parms : PEI */
/* purpose : release L1 link */
/* */
/***************************************************************************/
EXPORT int
DeaL1_SBC (pei)
BYTE pei;
{
register PEITAB *pt;
if (!(pt = GetPeitab_BASIC (pei)))
return (ACK_NOT_SUPPORTED);
if (!(pt->pt_state & PT_L1_CTRL))
return (ACK_NOT_SUPPORTED);
if (pt->pt_ModulMode != PT_MM_NT && pt->pt_ModulMode != PT_MM_LT_S)
return (ACK_WRONG_MODUL_MODE);
if (((pt->pt_CI_rec = inp (pt->pt_r_cixr)) & CIR_MASK) != CI_DIU)
{
if (pt->pt_state & PT_IOM2)
outp (pt->pt_r_cixr, CIXR_TBC | CI_DR | 0x03);
else
outp (pt->pt_r_cixr, CIXR_TBC | CI_DR);
return (ACK_DONE);
}
DECODE_L1_STATUS (pei, pt->pt_CI_rec);
return (ACK_DONE);
}
/***************************************************************************/
/* */
/* Function: IntL1_SBC () */
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/* Parms : pointer to PEITAB table element of ICC / ISAC-S */
/* purpose : handle C/I interrupts */
/* */
/***************************************************************************/
EXPORT void
IntL1_SBC (pt)
register PEITAB *pt;
{
pt->pt_CI_rec = inp (pt->pt_r_cixr);/* read CIRR (CIR0) register */
if (pt->pt_ModulMode == PT_MM_NT)
{
/* in NT / LT-S configuration: */
/* send DID if SBC/ISAC-S is in the */
/* DIU state */
/* -> deactivation */
if ((pt->pt_CI_rec & CIR_MASK) == CI_DIU)
{
if (pt->pt_state & PT_IOM2)
outp (pt->pt_r_cixr, CIXR_TBC | CI_DID | 0x03);
else
outp (pt->pt_r_cixr, CIXR_TBC | CI_DID);
}
}
else /* TE configuration: */
{ /* power down SBC/ISAC-S if it has */
/* changed from activated to */
/* pending mode */
if ((pt->pt_CI_rec & CIR_MASK) == CI_DR)
{
if (pt->pt_state & PT_IOM2)
outp (pt->pt_r_cixr, CIXR_TBC | CI_DIU | 0x03);
else
outp (pt->pt_r_cixr, CIXR_TBC | CI_DIU);
}
/* activation confirmation in IOM2 */
/* configurations. The SBC */
/* (ISAC-S) must confirm an */
/* activation from network side. */
/* Only then it will be transparent */
/* for upstream B channel data */
if ((pt->pt_state & PT_IOM2) &&
((pt->pt_CI_rec & CIR_MASK) == CI_AI))
outp (pt->pt_r_cixr, CIXR_TBC | CI_AR | 0x03);
}
DECODE_L1_STATUS (pt->pt_pei, pt->pt_CI_rec);
}
/***************************************************************************/
/* */
/* Function: ResL1_SBC () */
/* Parms : pointer to PEITAB table element of ICC / ISAC-S */
/* purpose : Reset SBC / L1 part of ISAC-S */
/* (also used for device test) */
Semicond uctor Group 235
Low Level Controller
/* */
/***************************************************************************/
EXPORT int
ResL1_SBC (pt)
register PEITAB *pt;
{
int i, state, failed = FALSE;
BYTE ForceCommand, NewState, ReleaseCommand, Loop, r_spcr;
switch (pt->pt_ModulMode)
{
case PT_MM_TE:
ForceCommand = CI_RS; /* send the RES (reset) code */
NewState = CI_EI; /* and wait for a change to the EI */
/* state, */
ReleaseCommand = CI_DIU; /* then send DIU */
break;
case PT_MM_NT:
ForceCommand = CI_DR; /* send the deactivation request */
/* code */
NewState = CI_DIU; /* and wait for DIU */
ReleaseCommand = CI_DID; /* then send DID to deactivate the */
/* SBC */
break;
default:
if (pt->pt_Lay1id == SBC_LAY1)
pt->pt_Lay1id = UNK_LAY1;
return (FALSE);
}
if (pt->pt_state & PT_IOM2)
{
ReleaseCommand |= 0x03;
ForceCommand |= 0x03;
}
state = ENTERNOINT (); /* disable all system interrupts */
/* if testloop mode was programmed */
/* switch it off to enable L1 */
/* status recognition */
r_spcr = inp (pt->pt_r_spcr);
if (Loop = (r_spcr & SPCR_TPL))
outp (pt->pt_r_spcr, (r_spcr & ~SPCR_TPL));
outp (pt->pt_r_mask, ~ISTA_CIC); /* allow only C/I interrupts */
if (pt->pt_ModulMode == PT_MM_TE)
EnaClk_SBC (pt);
/* output the command code */
outp (pt->pt_r_cixr, (BYTE) (CIXR_TBC | ForceCommand));
Semicond uctor Group 236
Low Level Controller
i = 0;
/* wait for the expected state */
while ((inp(pt->pt_r_cixr) & CIR_MASK) != NewState)
if (i++ > 20000)
{ /* break if timeout */
failed = TRUE;
break;
}
/* output the release command */
outp (pt->pt_r_cixr, (BYTE)(CIXR_TBC | ReleaseCommand));
if (pt->pt_ModulMode == PT_MM_TE) /* TE mode ? */
{ /* Wait for DIU or AIU because */
/* it can cause problems for the */
/* enable clock routine if the */
/* clocks disappear mid routine */
/* due to an earlier reset */
for (i = 0; i < 20000; i++)
{
pt->pt_CI_rec = inp (pt->pt_r_cixr) & CIR_MASK;
if ((pt->pt_CI_rec == CI_DIU) || (pt->pt_CI_rec == CI_AI))
break;
}
if ((pt->pt_state & PT_IOM2) && (pt->pt_CI_rec == CI_AI))
outp (pt->pt_r_cixr, CIXR_TBC | CI_AR | 0x03);
}
if (Loop) /* restore original value of SPCR */
outp (pt->pt_r_spcr, r_spcr);
outp (pt->pt_r_mask, 0x00); /* enable interrupts again */
LEAVENOINT (state);
if (failed)
{
if (pt->pt_Lay1id == SBC_LAY1)
pt->pt_Lay1id = UNK_LAY1;
return (FALSE);
}
else
return (TRUE);
}
Semicond uctor Group 237
Package Outlines
7 Package Outlines
2.54 1.5 max 0.45
+0.1
1.3
3.7
±0.3
0.5 min
5.1 max
40 21
120
50.9
-0.5
0.25 max
0.25
+0.1
14
-0.3
15.24
+1.2
15.24
±0.2
Index Marking
~
~
0.25 40x
P-DIP-40-2
(Plastic Dual-In-Line Package)
GPD05055
Dimensions in mm
Semicond uctor Group 238
Package Outlines
Plastic Package, P-LCC-44-1 (SMD)
(Plastic-Leaded Ch ip Carrier)
GPL05102
Dimensions in mm
Semicond uctor Group 239
Package Outlines
Plastic Package, P-MQFP-64-1 (SMD)
(Plastic Metric Quad Flat Package)
GPM05250
SMD = Surface Mounted Device
Sorts of Packing
Package outlines for tubes, trays etc. are contained in our
Data Book “Package Information”
Dimensions in mm
Semicond uctor Group 240
Package Outlines
Appendix
Transformers and Crystals Vendor List
Crystals:
Frischer Electronic
Schleifmü hls tr aße 2
D-91054 Erlangen, Germany
KVG
Waibstadter Stra ße 2-4
D-74924 Neckarbischofsheim 2, Germany
Tel.: (…7263) 648-0
NDK
2-21-1 Chome Nishihara Shibuya-Ku
Tokyo 151, Japan
Tel.: (03)-460-2111
or
Cupertino, CA, USA
Tel.: (408) 255-0831
Saronix
4010 Transport at San Antonio
Palo Alto, CA 94303, USA
Tel.: (415) 856-6900
or
via Arthur Behrens KG
Schrammelweg 3
D-82544 Egling-Neufahrn, Germany
Tele Quarz
Landstraße 13
D-74924 Neckarbischofsheim 2, Germany
Transformers:
Advanced Power Components (APC)
47 Riverside
Medway City Estate Strood
County of Kent, GB
Tel.: (044) 634-290 588
Pulse Engineering
P.O. Box 12235
San Diego, CA 92112, USA
Tel.: (619) 268-2454
or
4, avenue du Quebéc
F-91940 Les Ulis, France
or
Dunmore Road
Tuam County Galway, Ireland
Tel.: (093) 24107
S+M Components
Balanstraße 73
P.O. Box 801709
D-81617 Munich, Germany
Tel.: (…89) 4144-8041
Fax.: (…89) 4144-8483
Siemens Oostcamp
Belgium
Schott Corporation
Suite 108
1838 Elm Hill Pike, Nashville, TN 37210, USA
Tel.: (615) 889-8800
TDK
Christinenstr aße 25
D-40880 Ratingen 1, Germany
Tel.: (…2192) 487-0
Universal Microelectronics
Vacuumschmelze (VAC)
Grüner Weg 37
Postfach 2253
D-63412 Hanau 1, Germany
Tel.: (…6181) 380
or
186 Wood Avenue South
Iselin, NJ OB830, USA
Tel.: (908) 603 5905
Valor
Steinstraße 68
D-81667 München, Germany
Tel.: (…89) 480 2823
Fax.: (…89) 484 743
Vogt electronic AG
Postfach 1001
D-94128 Obernzell, Germany
Tel.: (…8591) 17-0
Fax.: (…8591) 17-240
