MB86681BPFVS-ES - Fujitsu - Datasheet.Directory

Datasheet

December 1997 Version 1.1

MB86681

ATM Switch Element (SRE-L)

FML/NPD/SRE-L/DS/1223

The FUJITSU MB86681 is a Self-Routing switch Element

(SRE-L) for use in ATM switch fabrics. It is ideally suited to

applications in a variety of customer premises equipment such

as ATM hubs and network access controllers. The device is

organized as a 4 x 4 switch with separate input and output ports

for matrix expansion. The main features of the device are listed

below:-

Features

• Highly integrated 4x4 structure.

• Active matrix expansion ports for row and column

interconnect.

• Selectable high and low priority output queues.

• Output port buff er capacity of 146 cells , which can be divided

into a 121 cell low priority queue and a 25 cell high priority

queue.

• Multicast support.

• Selective cell discard based on CLP bit and selectable

queue level.

• Selectable Explicit Forward Congestion Indication (EFCI)

function.

• Selectable Per VC EFCI marking.

• Selectable per Output queue Vertical Flow Control (VFC).

• Early Packet Discard (EPD) notiﬁcation capability.

• Flexible tag processing to allow a variety of switch fabric

architectures to be realized.

• All input / output ports operate at up to 40MHz using an 8-bit

data format.

• JTAG pins compatible with IEEE1149.1 are provided.

• Fabricated in sub-micron CMOS technology incorporating a

5V CMOS compatible I/O with a low power 3.3V logic core.

PLASTIC PACKAGE

SQFP208

PIN ASSIGNMENT

156

157

208 52

104

105

INDEX

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

TABLE OF CONTENTS

December 1997 Version 1.1
FML/NPD/SRE-L/DS/1223
MB86681 ATM Switch Element (SRE-L)
Copyright © 1996 Fujitsu Microelectronics Limited Page 3 of 71
TABLE OF CONTENTS (Continued)
APPENDICES
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
1 Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
2 Matrix Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
3 Delta Configuration  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
External Interfaces  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
1 Logical Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2 Detailed Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Initialization and Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
2 Recommended Clocking Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3 Reset Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
4 Initialization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
5 Initialization of a Master SRE-L Switch Element.. . . . . . . . . . . . . . . . . . . . . . . . .19
6 Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
6.1 Address Field Size / Location Configuration Registers . . . . . . . . . . . . .21
6.2 Column Address Configuration Register . . . . . . . . . . . . . . . . . . . . . . . .23
6.3 High Priority Queue Enable Configuration Register. . . . . . . . . . . . . . . .24
6.4 EFCI Enable / Disable Configuration Register. . . . . . . . . . . . . . . . . . . .25
6.5 EFCI Threshold Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . .25
6.6 Flexible Transmission Mode Configuration Register . . . . . . . . . . . . . . .25
6.7 Per VC EFCI Enable / Disable Configuration Register  . . . . . . . . . . . . .26
6.8 Per VC EFCI Fixed Threshold Configuration Register. . . . . . . . . . . . . .26
6.9 VFC Enable / Disable Configuration Register . . . . . . . . . . . . . . . . . . . .27
6.10 VFC Threshold Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . .27
7 Initialization of a Slave SRE-L Switch Element . . . . . . . . . . . . . . . . . . . . . . . . . .28
Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
1 Address Filtering Normal Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
1.1 Normal Routing Tag Control Field Format. . . . . . . . . . . . . . . . . . . . . . .30
1.2 Multicast Routing Tag Control Field Format. . . . . . . . . . . . . . . . . . . . . .34

December 1997 Version 1.1
FML/NPD/SRE-L/DS/1223
MB86681 ATM Switch Element (SRE-L)
Copyright © 1996 Fujitsu Microelectronics Limited Page 4 of 71
4.2  Address Filtering Multicast Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
4.3  Explicit Forward Congestion Indication (EFCI) function . . . . . . . . . . . . . . . . . . .39
4.4  Per VC EFCI function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
4.4.1 Per VC EFCI implemented on a Normal cell.. . . . . . . . . . . . . . . . . . . . .39
4.4.2 Per VC EFCI implemented on a Multicast cell. . . . . . . . . . . . . . . . . . . .41
4.5  Vertical Flow Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
4.6  Early Packet Discard Notification.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
4.7 JTAG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
4.7.1 Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
4.7.2 Test Access Port (TAP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
4.8  Test Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
5 Developers Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
5.1 External Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
5.1.1 ATM Cell Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
5.1.2 External Data Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
A Electrical Specification  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
A.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
A.2 Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
A.3 DC Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
B AC Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
C JTAG Boundary Scan Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
D Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
D.1 Pin Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
D.2 Pin Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
E Package Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

December 1997 Version 1.1
FML/NPD/SRE-L/DS/1223
MB86681 ATM Switch Element (SRE-L)
Copyright © 1996 Fujitsu Microelectronics Limited Page 5 of 71
LIST OF FIGURES
LIST OF FIGURES (Continued)
Figure 1 SRE-L Matrix Interconnect. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Figure 2 Delta Switch Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Figure 3 MB86681 I/O Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Figure 4 SRE-L Clocking Strategy (Master/Slave Configuration). . . . . . . . . . . . . . . . . . . .17
Figure 5 MB86681 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Figure 6 Use of INITIN and INITOUT pins for Initialization  . . . . . . . . . . . . . . . . . . . . . . . .19
Figure 7 Address Size/Location Inter-relationship . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Figure 8 Column Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Figure 9 Init line serial data format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Figure 10 Address Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Figure 11 Normal Routing Tag Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Figure 12 Routing Tag Format for Multicast operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Figure 13 Multicast Operation with a 64 x 64 Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Figure 14 Normal Routing Tag permitting Per VC EFCI Marking (EFCIT1 EFCIT0)>0 . . . .40
Figure 15 Non-Multicast Server Routing Tag permitting Per VC EFCI Marking. . . . . . . . . .41
Figure 16 Multicast Server Routing Tag permitting Per VC EFCI Marking  . . . . . . . . . . . . .42
Figure 17 Flow Control Packet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Figure 18 Serial Flow Control connectivity example  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Figure 19 EPD1 Bus connectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Figure 20 ATM Cell Header Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Figure 21 Cell Stream Transmission Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Figure 22 Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Figure 23 Input Clock Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Figure 24 I-Input Port Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Figure 25 E-Input Port Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Figure 26 Output Port Timing-FCS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Figure 27 Output Port Timing-IFCS Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Figure 28 INIT Port Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Figure 29 EPD Port Timing  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 30 Vertical Flow Control Port Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

Figure 31 JTAG Port TRST Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

Figure 32 JTAG Port Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

Figure 33 MB86681 Pin Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

December 1997 Version 1.1
FML/NPD/SRE-L/DS/1223
MB86681 ATM Switch Element (SRE-L)
Copyright © 1996 Fujitsu Microelectronics Limited Page 7 of 71
LIST OF TABLES
Table 1 Column Address Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Table 2 EFCI Threshold Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Table 3 Per VC EFCI Fixed Threshold Coding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Table 4 Output queue Flow Control Threshold Coding. . . . . . . . . . . . . . . . . . . . . . . . . . .27
Table 5 Master/Slave Configuration table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Table 6 Discard Threshold Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Table 7 Per VC EFCI Marking Threshold Coding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Table 8 Reset AC Timing Parametrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Table 9 IPCLK/EPCLK AC Timing Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Table 10 I-Input Port AC Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Table 11 E-Input Port AC Timing Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Table 12 Output Port FCS Mode AC Timing Parameters. . . . . . . . . . . . . . . . . . . . . . . . . .56
Table 13 Output Port IFCS Mode AC Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . .57
Table 14 INIT Port AC Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Table 15 EPD Port AC Timing Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
Table 16 Vertical Flow Control Port AC Timing Parameters. . . . . . . . . . . . . . . . . . . . . . . .59
Table 17 JTAG TRST AC Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Table 18 JTAG Port AC Timing Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

1 Introduction

1.1 Outline

The Fujitsu MB86681 is a Self-Routing ATM cell switch Element (SRE-L) which can be used as a basic

building block for a variety of 155 to 300Mb/s ATM switch fabrics.

The device provides 4 output data queues, one for each output port and each with an aggregate storage

capacity of 146 cells per output port. A 24 bit routing tag is used to decide into which output queue a

particular cell will be loaded.

Each output queue is divided into a high and low priority section. A control bit in the routing tag determines

the cell priority. High priority cells will always be forwarded in preference to low priority cells. Hence cells

using the high priority queues will suffer less queueing delay and will have a lower cell loss rate than cells

using the low priority queues (assuming that high priority traffic only forms a small portion of total traffic).

The switch element includes four expansion inputs, which are provided to facilitate easy expansion in the

form of a matrix. Cells received via the expansion inputs are directed into the attached output data queue.

1.2 Matrix Conﬁguration

Various interconnection topologies can be applied to the SRE-L. However, the device is ideally suited to

interconnection in the form of a matrix. In this case the SRE-L provides re-timed active outputs which allow

direct connection to nearest neighbours. This eliminates the need for passive buses and reduces device

interconnect problems at the board level. A matrix architecture is illustrated in Figure 1.

The number of switch elements required for an N x N switch is proportional to N2 and hence is only

appropriate for relatively small switch fabrics (e.g. 32 X 32). For larger switches, individual matrices can be

interconnected using a multi-path delta arrangement.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 1 SRE-L Matrix Interconnect

1.3 Delta Conﬁguration

Larger switches may be realized by connecting SRE-L matrices into switch topologies similar to the two

stage delta configuration as illustrated in Figure 2.

Each switch element allows a selectable region of the tag field to be used for address filtering.

This is illustrated in Figure 2 where SRE-L elements in stages 1 and 2 are configured with different Address

Location Fields. Consequently, stage 2, SRE-L switch elements are configured to examine a different

portion of the ATM cell’s routing tag from that examined by SRE-L elements in stage 1.

As a consequence of the selectable address field multi-path, delta switches can be constructed without the

need for intermediate address translation/tag generation.

E1 E2 E3 E4

SRE-L

E1 E2 E3 E4

SRE-L

E1 E2 E3 E4

SRE-L

E1 E2 E3 E4

SRE-L

E1 E2 E3 E4

SRE-L

E1 E2 E3 E4

SRE-L

E1 E2 E3 E4

SRE-L

E1 E2 E3 E4

SRE-L

E1 E2 E3 E4

SRE-L

E1 E2 E3 E4

SRE-L

E1 E2 E3 E4

SRE-L I2

E1 E2 E3 E4

SRE-L

O1 O2 O3 O4

O2 O3 O4

O1 O2 O3 O4

O2 O3 O4

O1 O2 O3 O4

Switch Conﬁguration Parameters

Output Ports

Regeneration Ports

Input Ports

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 2 Delta Switch Conﬁguration

I32

I33

I34

I64

I65

I66

I96

SRE-L SRE-LSRE-L

E2E3E4E2E3E4

E1 E2E3E4

E1 E2E

SRE-L SRE-LSRE-L

E2E3E4E2E3E4

E1 E2E3E4

E1 E2E

EP1DT5=L

EP1DT4=L

EP1DT3=L

EP1DT2=H

EP1DT5=L

EP1DT4=L

EP1DT3=H

EP1DT2=L

ATM Cell

ADDRESS

FIELD

LOCATION

ADDRESS

FIELD

LOCATION

STAGE 1 STAGE 2

PCMCCLT

O32

O33

O34

O64

O65

O66

O96

Address Field 1Address Field 2Address Field 3Address Field 4

SRE SRE

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

2 External Interfaces

2.1 Logical Outline

A logical view of the MB86681’s external pins is illustrated in Figure 3 and a physical pin assignment is

shown in Appendix D.

Figure 3 MB86681 I/O Block Diagram

TDO

Expansion ports

Input

ports

Regeneration

ports

INITOUT

OP1

Port OP2

Port OP3

Port OP4

Port

IP1

Port

IP2

Port

IP3

Port

IP4

Port

RP1

Port

RP2

Port

RP3

Port

RP4

Port

RESET

IPCLK

EPCLK INITIN

JTAG

port

TMS

TCK

TRST

EP1

Port EP2

Port EP3

Port EP4

Port

VFCI

VFCO EPD1-4

MB86681

Output ports

TDI

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

2.2 Detailed Description

A brief description of each of the MB86681’s input and output pins shall now be given.

RESET

An active low pulse applied to the MB86681’s RESET pin will cause an MB86681 switch element to

execute an internal Reset instruction cycle. The instruction will only be executed when a clock signal is

applied to the IPCLK pin. A minimum of 2 IPCLK clock cycles will be required to complete the Reset

instruction cycle.

IPCLK

Data present on the input ports IP1DTx to IP4DTx is sampled on the rising edge of this clock. This clock

needs to be present if a complete Reset instruction cycle is to be executed following an active low transition

on the RESET pin.

EPCLK

Data present on the input ports EP1DTx to EP4DTx is sampled on the rising edge of this clock.

The EPCLK input pin can also be used by an MB86681 switch element to determine whether the switch

element should act as Master or as a Slave. If the EPCLK input pin is permanently tied to VSS then the

switch element is deemed to be a Master switch element.

If however a clock is present on the EPCLK input pin then the MB86681 switch element is deemed to be

a Slave switch element.

Note:

It is recommended that for general usage the IPCLK and EPCLK input ports are connected together as

shown in SRE-L Clocking Strategy (Master/Slave Configuration).

Input Ports (IPxSOC, IPxDTx)

The device comprises four primary input ports, (IP1SOC, IP1DTx) to (IP4SOC, IP4DTx), each of which is

organized as 8-bit parallel data together with a start of cell (IPxSOC) bit. All primary input data is sampled

on the rising edge of an input clock signal (IPCLK). Incoming data comprises a 3 byte routing tag followed

by a 53 byte ATM cell.

Any unused I-input ports should have their unused IPxSOC pin tied to VSS.

Expansion Ports (EPxSOC, EPxDTx)

The four expansion ports, (EP1SOC, EP1DTx) to (EP4SOC, EP4DTx), are provided for column

interconnect in a matrix architecture. The data format on the expansion ports is similar to the primary input

port format, except that data is synchronized to an expansion port clock (EPCLK), which is usually provided

by the vertically opposite nearest neighbour switch element.

Master Switch elements at the top of each column do not need their expansion ports, in this case, the input

pins will take on different functions in order to allow the routing tag characteristics to be defined. Pin

functions are described in Section Configuration Registers.

The alternative functions are selected by connecting the EPCLK input signal to VSS.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Any unused Expansion ports should have their unused EPxSOC pin tied to VSS.

VFCI

The VFCI, Vertical Flow Control Input port, permits per queue flow control to be carried out when

programmed High and Low priority queue thresholds are exceeded.

When enabled, the MB86681 switch element synchronizes to the VFCI serial highway by detecting the

SYN character as defined in International Alphabet No.5.

When not in use the VFCI pin should be tied to either VSS or VD5.

VFCO

The VFCO, Vertical Flow Control Output port, is used by the MB86681 switch element to transmit flow

control data to the switch element’s vertically opposite neighbour.

The active high flow control data present on this serial highway permits vertical flow control on cell

boundaries, thereby no cell loss is guaranteed once a cell has been routed.

INITIN

The INITIN is used by Slave MB86681 switch elements to acquire configuration data immediately following

a RESET instruction cycle.

The configuration data may be supplied via the INITOUT pin of a Master switch element or from a device

emulating the configuration capability of a Master switch element.

When the MB86681 switch element is deemed to be Master i.e its EPCLK input is tied to VSS, the INITIN

pin is not used and should be tied to VD5.

INITOUT

The INITOUT pin is used by Master switch elements to convey the configuration data, acquired through

their Expansion port pins, in a serial format to the attached Slave elements.

Slave switch elements do not use their INITOUT pin. When a switch element is configured as a Slave, the

INITOUT pin is driven permanently high.

Following an active low transition on the RESET pin the INITOUT pin shall be driven to it’s logic “1” state.

Regeneration Ports (RPxSOC, RPxDTx)

Four regeneration ports, (RP1SOC, RP1DTx) to (RP4SOC, RP4DTx), are provided for matrix

interconnection.

The Flexible Transmission Mode (FTM) feature of the SRE-L permits the synchronous transmission of the

Regeneration-Port data to take place on either the rising or falling edge of the IPCLK.

Following a RESET instruction cycle the Regeneration-Port pins are driven to their logic “0” state.

Output Ports (OPxSOC, OPxDT)

Four output ports, (OP1SOC, OP1DTx) to (OP4SOC, OP4DTx), provide the primary switch output data.

The data format is identical to all other ports.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

As in the case of the Regeneration-Port data, the Flexible Transmission Mode (FTM) feature of the SRE

permits the synchronous transmission of the Output-Port data to take place on either the rising or falling

edge of the IPCLK.

Following a RESET instruction cycle the Output-Port pins are driven to their logic “0” state.

When no data is being output the SRE shall drive these outputs to their logic “0” state.

EPD1 - EPD4

The 4 pseudo open collector Early Packet Discard (EPD) notification ports, EPD1 to EPD4, are active low

tristate output ports. The 4 EPD ports permit early notification that a cell currently being received has been

discarded by the MB86681 switch element.

TCK

The TCK input pin provides the clock signal for the JTAG internal test logic. Data received on the TDI input

pin shall be sampled on the rising edge of TCK clock signal.

TRST

The TRST input pin provides an asynchronous reset signal for the JTAG internal test logic. An active low

transition on this pin will force the JTAG TAP Controller into it’s Test-Logic-Reset state.

An External pull-up should be connected to this input to ensure that when this input is not driven, a

response identical to the application of a logical 1 results.

TMS

The TMS input pin shall be sampled on the rising edge of the TCK clock and decoded by the JTAG internal

test logic to control test operations.

An External pull-up should be connected to this input to ensure that when this input is not driven, a

response identical to the application of a logical 1 results.

TDI

The TDI input pin shall provide a port through which JTAG serial test data and instructions may be received

by the internal test logic.

An External pull-up should be connected to this input to ensure that when this input is not driven, a

response identical to the application of a logical “1” results.

TDO

The TDO output pin represents a tristate serial output JTAG port through which test instructions and data

from the internal test logic may be conveyed. Changes in the state of the signal driven through TDO shall

only occur following the falling edge of TCK. When no signal is being driven through the TDO port the

output pin should revert to its tristate condition.

Immediately following power-up the TDO output pin shall remain in its undriven tristate state.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

TST1..TST4

Four test pins are provided for internal use only. It is recommended that test pins TST1, TST2 and TST3

are connected to VSS.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

3 Initialization and Conﬁguration

3.1 Overview

A block diagram of the switch element is illustrated in Figure 5. From this, it can be seen that each of the

I-input ports is connected in parallel to an address filter via a high speed multiplexer. The address filter

processes the address bits contained in a 24 bit routing tag and if appropriate, the associated cell will be

routed through to the desired FIFO buffer. The MB86681 switch element permits each output FIFO to be

sub-divided into a high and low priority section. The address filter examines each received cell’s routing

tag to determine its priority level.

Each output port is serviced by a High/Low priority multiplexer which removes cells from the high and low

priority queues. The multiplexer will always give preference to high priority cells.

The above functions are described in more detail in the following paragraphs.

3.2 Recommended Clocking Strategy

The recommended SRE-L matrix clocking strategy for a Master / Slave configuration is shown in SRE-L

Clocking Strategy (Master/Slave Configuration). Note that the recommendation requires both the IPCLK

and EPCLK ports within the Column of a matrix to be connected together.

Use of INITIN and INITOUT pins for Initialization illustrates how a pure Slave SRE-L matrix may be

clocked.

3.3 Reset Operation

The MB86681 provides an active low RESET pin. Asynchronous transitions on this pin are captured

internally by the MB86681 and synchronized to the IPCLK clock. The internal synchronous RESET

operation of the MB86681 is deemed to be complete 2 IPCLK clock periods after the removal of the active

low RESET signal.

All outputs shall be reset to their inactive states within 2 IPCLK clock periods after an active low pulse has

been applied to the RESET pin.

The MB86681 requires the presence of the IPCLK clock signal to complete a RESET operation.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 4 SRE-L Clocking Strategy (Master/Slave Conﬁguration)

3.4 Initialization.

The Configuration Manager block illustrated in Figure 5 is responsible for initialising an MB86681 switch

element. An MB86681 switch element may be initialised/configured by one of two mechanisms depending

on whether the element is a Master or a Slave element.

Figure 6 illustrates how the INITIN and INITOUT pins of Master and Slave elements may be connected in

order to allow initialisation of the respective elements.

Master MB86681 switch elements obtain their configuration data from the unused Expansion port pins as

shown in Figure 6a, while Slave elements may obtain their configuration data from either the INITOUT pin

of a Master element (as in Figure 6a) or from a Programmable Logic Device (PLD), such as that shown in

Figure 6b, capable of transferring a serial data stream identical to that shown in Figure 9.

MB86681 elements enter their Initialization phase when the RESET operation described above is

complete.

EPCLK EP1 EP4

IPCLK

EPCLK EP1 EP4

IPCLK

EPCLK EP1 EP4

IPCLK

MASTER

Switch Element

SLAVE

Switch Element

VSS

CONFIGURATION DATA

unused

SLAVE

Switch Element

CLK

EPCLK EP1 EP4

IPCLK

EPCLK EP1 EP4

IPCLK

EPCLK EP1 EP4

IPCLK

MASTER

Switch Element

SLAVE

Switch Element

VSS

CONFIGURATION DATA

unused

SLAVE

Switch Element

CLK

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 5 MB86681 Block Diagram

Expansion

Ports

MUX

Input Ports

Regeneration Ports

Output Holding Registers

Conﬁguration

Manager

Expansion Port

Holding

Registers

Input Port

Holding

Registers

Address Filter

Output

Ports

JTAG Interface

JTAG

Buffer Timing

& Control

146 Cell

Output

Buffer

Buffer Timing

& Control

146 Cell

Output

Buffer

Buffer Timing

& Control

146 Cell

Output

Buffer

Buffer Timing

& Control

146 Cell

Output

Buffer

VFC & EPD

Controller

EPD & VFC Interface

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 6 Use of INITIN and INITOUT pins for Initialization

3.5 Initialization of a Master SRE-L Switch Element.

An MB86681 switch element shall be deemed to be a Master when its EPCLK pin is permanently tied to

Vss. In such a configuration, the SRE-L switch element may be internally configured via the data present

on Expansion ports EP1DTx, EP2DTx & EP3DTx.

The data present on the three expansion ports is immediately parallel loaded into the eleven Master switch

element Configuration registers following a master reset instruction cycle operation.

A total of 20 input pins are used to configure the operating mode of the MB86681. These inputs are shared

EPCLK EP1 EP4

IPCLK

INITIN

INITOUT

EPCLK EP1 EP4

IPCLK

INITIN

INITOUT

EPCLK EP1 EP4

IPCLK

INITIN

INITOUT

EPCLK EP1 EP4

IPCLK

INITIN

INITOUT

EPCLK EP1 EP4

IPCLK

INITIN

INITOUT

EPCLK EP1 EP4

IPCLK

INITIN

INITOUT

MASTER

Switch Element

SLAVE

Switch Element

VSS

CONFIGURATION DATA

a) Conﬁguration Data from the unused

Expansion Ports b) Conﬁguration Data from

INITIN pins

unused used

SLAVE

Switch Element SLAVE

Switch Element

SLAVE

Switch Element

SLAVE

Switch Element

Programmable

Logic Device

CLK CLK

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

with Expansion port inputs and are selected by configuring the switch element as a Master.

Once configured, a Master switch element commences transferring the contents of it’s Configuration

registers to the connected Slave elements. The transfer of Configuration data between the Master and

Slave elements is accomplished by the Master switch element transmitting the contents of it’s

Configuration registers in a serial format via the INITOUT pin to connected Slave device’s INITIN pin, as

shown in Figure 6.

3.6 Conﬁguration Registers

The MB86681 switch element provides 11 user definable configuration registers. The configuration

registers may be configured via the Expansion port pins for Master devices or via the serial input port,

INITIN, for the Slave devices.

A list of the eleven Configuration registers together with the associated Expansion port pins used to

configure them on a Master device is given below.

1. Address Field Size

AFS1..AFS0(EP1DT7..EP1DT6)

2. Address Field Location

AFL3..AFL0(EP1DT5..EP1DT2)

3. Column Address

CA2..CA0(EP2DT7..EP2DT5)

4. High Priority Queue Enable

HPQE(EP2DT4)

5. EFCI Enable / Disable control

EFCIE(EP2DT3)

6. EFCI Thresholds

EFCIT1..EFCIT0(EP2DT2..EP2DT1)

7. Flexible Transmission Mode

FTM(EP3DT7)

8. Per VC EFCI Enable / Disable control

PEFCIE(EP3DT6)

9. Per VC EFCI Fixed Thresholds

PEFCIT1..PEFCIT0(EP3DT5..EP3DT4)

10. VFC Enable / Disable

VFCE(EP3DT3)

11. VFC Thresholds

VFCT1..VFCT0(EP3DT2..EP3DT1)

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

A description of the different functions associated with these Configuration registers is now given.

3.6.1 Address Field Size / Location Conﬁguration Registers

The Expansion port pins EP1DT7 to EP1DT2 are used by Master MB86681 switch elements to configure

their Address Field Size (AFS) and Location (AFL) registers immediately following a master RESET

instruction cycle. The Address Field Size and Location registers are two inter-dependent registers, used

by the MB86681 device to select a subset of routing tag bits which are to be used for address filtering.

The address field size may vary from 2 bits (for Batcher/Banyan type topologies) to a maximum of 5 bits

(for a 32 X 32 matrix).

With a 5-bit address field, there are 4 possible locations within the 24-bit tag (note the upper 4 bits are used

for control information). With a 2-bit address field there are 10 possible locations. The relationship between

address field size and location within the routing tag is illustrated in Figure 7.

Figure 7 also illustrates how the switch elements shall interpret the Address size/location inter-relationship

table to acquire the valid address field within the routing tag, when configured with an address size of four

bits and a start address field location of PA8.

Note:

The AFS field in the configuration registers is not applicable to multicast cells.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 7 Address Size/Location Inter-relationship

EP1DT7 EP1DT6 Address size

2 bits

3 bits

4 bits

5 bits

EP1DT5 EP1DT4 EP1DT3 EP1DT2 Start of Address ﬁeld location

within tag

0000 1

000 1000

100

1000 100

PA0

PA5

PA10

PA0

PA4

PA12

PA0

PA3

PA6

PA9

PA12

PA15

PA0

PA2

PA4

PA6

PA8

PA10

PA12

PA14

PA16

Address Field Location Pins

Address Size Pins

PC MC CLT1 CLT0 PA0 PA1 PA2

PA4 PA5 PA6 PA7 PA8 PA9 PA10 PA11

PA12 PA13 PA14 PA15

PA3

PA16 PA17 PA18 PA19

1st Octet

AFS1 AFS0

AFL3 AFL2 AFL1 AFL0

PA8

PA18

PA15 PA12

PA16

2nd Octet

3rd Octet

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

3.6.2 Column Address Conﬁguration Register

The Expansion port pins EP2DT7 to EP1DT5 are used by Master MB86681 switch elements to configure

their Column Address register immediately following a master RESET instruction cycle. The 3 bit Column

Address Configuration register is used to define the base address for the switch element when it is used

in a matrix configuration. The Column Address allows the switch element to determine which of the switch

matrix Columns it resides in and hence the group of output ports to which it is attached.

Table 1 Column Address Coding

Table 1 illustrates the valid Column Address permutations whilst Figure 8 illustrates how individual

elements may be configured within a switch matrix.

Column Address Column

Group

CA1

EP2DT7 CA2

EP2DT6 CA3

EP2DT5

0 0 0 1-4

0 0 1 5-8

0 1 0 9-12

0 1 1 13-16

1 0 0 17-20

1 0 1 21-24

1 1 0 25-28

1 1 1 29-32

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 8 Column Addressing

3.6.3 High Priority Queue Enable Conﬁguration Register

The Expansion port input pin EP2DT4 is used by Master switch elements, immediately following a master

RESET instruction cycle, to enable or disable the high priority queue mechanism associated with each

output buffer. When tied to VSS, the Dual queue per port mode of operation is invoked. In this configuration

mode the high priority queue is enabled providing the user with a 25 cell High priority queue and a 121 cell

Low priority queue per output port.

When the Expansion port input pin EP2DT4 is tied to VD5, for a Master switch element, the Mono queue

per port mode of operation is invoked. In this operating mode the two output queues are merged to form a

single 146 cell output queue per port.

SRE-L (57) Ο1Ο2Ο3Ο4Ο1Ο2Ο3 SRE

14 58 91213161720212425282932

SRE-L (2)

EP1DT7=H

EP1DT6=H

EP1DT5=L

EP1DT4=L

EP1DT3=L

EP1DT2=L

EP2DT7=L

EP2DT6=L

EP2DT5=H

EP2DT4=L

EP2DT3=H

EP2DT2=H

EP2DT1=H

EP3DT7=L

EP3DT6=L

EP3DT5=L

EP3DT4=L

EP3DT3=L

EP3DT2=L

EP3DT1=L

SRE-L (8)

EP1DT7=H

EP1DT6=H

EP1DT5=L

EP1DT4=L

EP1DT3=L

EP1DT2=L

EP2DT7=H

EP2DT6=H

EP2DT5=H

EP2DT4=L

EP2DT3=H

EP2DT2=H

EP2DT1=H

EP3DT7=L

EP3DT6=L

EP3DT5=L

EP3DT4=L

EP3DT3=L

EP3DT2=L

EP3DT1=L

32 X 32 PORT SWITCH

SRE-L (1) SRE-L (2) SRE-L (8)

SRE-L (64)

SRE-L (1)

EP1DT7=H

EP1DT6=H

EP1DT5=L

EP1DT4=L

EP1DT3=L

EP1DT2=L

EP2DT7=L

EP2DT6=L

EP2DT5=L

EP2DT4=L

EP2DT3=H

EP2DT2=H

EP2DT1=H

EP3DT7=L

EP3DT6=L

EP3DT5=L

EP3DT4=L

EP3DT3=L

EP3DT2=L

EP3DT1=L

Ο1Ο2Ο3 Ο4 Ο1Ο2Ο3Ο4 Ο1Ο2Ο3Ο4

Ε1 Ε2 Ε3 Ε4Ε1 Ε2 Ε3 Ε4Ε1 Ε2 Ε3 Ε4Ε1 Ε2 Ε3 Ε4Ε1 Ε2 Ε3 Ε4 Ε1 Ε2 Ε3 Ε4 Ε1 Ε2 Ε3 Ε4 Ε1 Ε2 Ε3 Ε4

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

3.6.4 EFCI Enable / Disable Conﬁguration Register

On a Master MB86681 switch element, the Expansion port input pin (EP2DT3) may be used to Enable/

Disable the Explicit Forward Congestion Indication (EFCI) function. When this pin is tied to VSS on a Master

MB86681 element, the EFCI function will be disabled both on the Master switch element and any attached

Slave elements (note Slave elements are configured by the INITIN and INITOUT configuration illustrated

in Figure 6a).

When the EP2DT3 pin is tied to VD5, on a Master switch element, the EFCI function will be enabled on both

the Master element and any attached Slave elements.

3.6.5 EFCI Threshold Conﬁguration Register

The Expansion port pins (EP2DT2 and EP2DT1) on a Master switch element may be used to select the

Output data queue fill level thresholds at which the EFCI function may be implemented. Table 2 illustrates

how the logic levels applied to these pins are interpreted by the Master and attached Slave elements.

Table 2 EFCI Threshold Coding

Note:

The terms and conditions permitting EFCI marking as described above may only be superseded by

ATM cells permitting Per VC EFCI marking being received by an MB86681 switch element with it’s

Per VC EFCI marking function enabled.

3.6.6 Flexible Transmission Mode Conﬁguration Register

The Expansion port pin (EP3DT7) on a Master SRE-L may be used to select a transmission edge for the

O and R-Port data.

When the EP3DT7 pin is tied to VSS the data present on the O and R-ports is transmitted synchronous to

the falling edge of the IPCLK. This transmission mode is referred to as the Fujitsu Cell Stream (FCS) mode

of operation.

When the EP3DT7 pin is tied to VDD the data present on the O and R-ports is transmitted synchronous to

the rising edge of the IPCLK.This transmission mode is referred to as the Inverse Fujitsu Cell Stream

EFCIT 1

EP2DT2 EFCIT 0

EP2DT1 EFCI

Threshold

0 0 Not Used

0 1 20% full

1 0 50% full

1 1 80% full

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

(IFCS) mode of operation.

When operating in the FCS mode, data present on each input is sampled on the rising edge of its

respective clock whilst data transitions on the Output and Regeneration ports take place on the falling edge

of the IPCLK signal.

When operating in the IFCS mode, data present on the Inputs will be sampled on the rising edge of their

respective clocks whilst data transitions on the Cell Stream Output Ports and Regeneration ports will take

place on the rising edge of the IPCLK signal.

Note:

When operating the SRE-L devices at 40Mhz, it is recommended that the IFCS mode is used.

3.6.7 Per VC EFCI Enable / Disable Conﬁguration Register

On a Master switch element, the Expansion port pin (EP3DT6) may be used to Enable/Disable the Per VC

Explicit Forward Congestion Indication (EFCI) function. When this pin is tied to VSS, the Per VC EFCI

function will be disabled both on the Master and any attached Slave MB86681 elements (assuming a

configuration as illustrated in Figure 6a).

When the EP3DT6 pin is tied to VD5, on a Master MB86681 switch element the Per VC EFCI function will

be enabled on both the Master and any attached Slave MB86681 elements.

Note:

When both the MB86681’s EFCI and Per VC EFCI functions are enabled, the Per VC EFCI function

will take precedence.

Consequently, ATM cells permitting Per VC EFCI marking will only be subject to EFCI marking

when their programmed EFCI Thresholds are equalled or exceeded.

3.6.8 Per VC EFCI Fixed Threshold Conﬁguration Register

The Expansion port pins (EP3DT5 and EP3DT4) on a Master MB86681 element may be used to select the

output data queue fill level thresholds at which the Per VC EFCI function may be implemented. Table 3

illustrates how the logic levels applied to these pins are interpreted by the Master and attached Slave

elements.

Table 3 Per VC EFCI Fixed Threshold Coding

EFCIT 1

EP3DT5 EFCIT 0

EP3DT4 EFCI

Threshold

0 0 Not Used

0 1 20% full

1 0 50% full

1 1 80% full

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Note:

The programmable EFCI Fixed Thresholds are only applicable to MB86681 devices configured as

Non-multicast servers.

3.6.9 VFC Enable / Disable Conﬁguration Register

On a Master MB86681 element, the Expansion port pin (EP3DT3) may be used to Enable/Disable the

Vertical Flow Control (VFC) function.

When the EP3DT3 pin is tied to VD5, the Vertical Flow Control function will be enabled on both the Master

and attached Slave elements.

3.6.10 VFC Threshold Conﬁguration Register

The Expansion port pins (EP3DT2 and EP3DT1) on a Master MB86681 element may be used to select the

Vertical Flow Control Thresholds, which when equalled or exceeded cause the MB86681 switch element’s

vertical queue flow control function to be implemented. Table 4 illustrates how the logic levels applied to

these pins are interpreted by the Master and attached Slave elements.

Table 4 Output queue Flow Control Threshold Coding

Note:

When operating in the Dual queue mode, the upper VFC Threshold for the High priority queue is

80% and not 95%.

OQFCT 1

EP3DT2 OQFCT 0

EP3DT1 Output Queue

Flow Control

Threshold

(OQFCT)

0 0 Not Used

0 1 50% full

1 0 80% full

1 1 95% full

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

3.7 Initialization of a Slave SRE-L Switch Element

Immediately following a master RESET instruction cycle, Slave switch elements commence monitoring

their INITIN pins. Unlike Master devices, the Slave switch elements use their serial INITIN input port to

acquire configuration data.

On detecting the active low Start sync bit, as shown in Figure 9, the Slave switch element uses its IPCLK

clock signal to determine the nominal centre bit position of the serial data stream. Multiple sampling of the

serial data stream is carried out to eliminate the possible detection of a false start polarity.

On detecting the valid Start sync bit, the Slave switch element shall sample each bit of the received

initialization character by counting 5 clock periods from the preceding bit’s nominal centre until all the

necessary configuration data has been acquired and loaded into the Configuration registers.

On acquiring their configuration data, the Slave switch elements cease to monitor their INITIN pins.

Figure 9 in conjunction with Table 5 illustrates the format of the data on this serial highway together with

the order of transmission.

Figure 9 Init line serial data format

Transmission of data on the serial INITOUT/INITIN serial highway shall primarily be of an asynchronous

format with data bit periods equal to the IPCLK/5. The transmitted data will not necessarily be phase

aligned to the IPCLK. The INITOUT port data transitions are synchronised to the falling edge of IPCLK/5

and are sampled by Slave switch elements on the rising edge of their IPCLK.

Master switch elements commence transmission by driving the INITOUT pin low. The configuration data

will then be transmitted in the format shown in Figure 9.

Figure 9 shows how the configuration data presented at the Expansion ports of a Master switch element

is translated into the serial bit stream illustrated in Figure 9. The data is transmitted serially with the most

significant bits occupying the lower bit positions of the INITOUT line.

All other unused Expansion port input pins are reserved for internal use and should be connected to VSS.

Start

sync

123 19 20

Normally

High

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Table 5 Master/Slave Conﬁguration table

Function Expansion Port Pins Init line Bit Position(s)

(Master Conﬁguration) (Slave Conﬁguration)

Address Field size EP1DT7..EP1DT6 Bits 1..2

Address Field location EP1DT5..EP1DT2 Bits 3..6

Column Group EP2DT7..EP2DT5 Bits 7..9

High Priority

Queue Enable EP2DT4 Bit 10

EFCI

Enable/Disable EP2DT3 Bit 11

control

EFCI Thresholds EP2DT2..EP2DT1 Bits 12..13

FTM EP3DT7 Bit 14

Per VC EFCI

Enable/Disable EP3DT6 Bit 15

Control

Per VC EFCI

Fixed Thresholds EP3DT5..EP3DT4 Bits 16..17

Output Queue

Flow Control EP3DT3 Bit 18

Enable/disable

Output Queue

Flow Control EP3DT2..EP3DT1 Bits 19..20

Thresholds

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

4 Functional Description

4.1 Address Filtering Normal Operation

ATM Cells arriving at the ingress side of the MB86681 element will have a 3 byte routing tag appended to

the head of the ATM Cell. The 3 byte routing tag is used by the MB86681 switch elements to carry out

Address filtering functions in conjunction with selective cell discard operations on the incoming cell. Figure

10 illustrates the main principles of operation.

The switch elements use the Start Of Cell (IPxSOC) signal to locate the 3 byte routing tag. On acquiring

the routing tag the MB86681 switch elements commence the interpretation of the various fields therein.

Figure 10 illustrates how the MB86681 switch elements receives ATM Cells 1 and 2 on it’s ingress side

and then proceeds to route both the Cell and it’s associated routing tag to the required output port.

The MB86681 switch element is capable of distinguishing between two types of cells. The two cell types

are differentiated by the formats of their routing tags. The two routing tag formats are referred to as:

1. The normal routing tag format

2. The Multicast routing tag format

The normal routing tag format is illustrated in Figure 10 appended to ATM Cells 1 and 2, whilst a more

detailed description of the significance of the bits in this routing tag is shown in Figure 11.

4.1.1 Normal Routing Tag Control Field Format

A description of the function of the bits within this routing tag shall now be given commencing with the

Priority control bit.

Priority Control (PC) Bit

The Priority Control (PC) bit determines whether the associated cell is loaded into the high priority queue

or the low priority queue. This bit should be set on a per virtual circuit basis in order to guarantee that cell

sequence numbering is preserved.

High priority channels should only be used for delay sensitive (or loss sensitive) data, and the total amount

of traffic allocated to high priority channels should form a small percentage of the total available output

bandwidth.

When the switch elements are configured for single / mono queue mode of operation the PC bit has no

significance.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Cell Loss Threshold Field CLT0,CLT1

Cell Loss Threshold Field CLT0, CLT1

These bits are used to control the treatment of cells which have the CLP bit in their ATM cell header set.

They determine the output queue fill level at which the cells will be selectively discarded.

Table 6 Discard Threshold Coding

Note:

When operating in the Dual queue mode, the Cell loss Threshold field is only applicable to ATM

Cells with their PC bit set to “0”.

When operating in the Mono queue mode, all ATM cells are treated as Low priority cells irrespective

of the Status of their PC bit and consequently will be subject to selective cell discard if the above

criteria are met.

Routing Field PA0-PA19

The routing Field PA0 to PA19 is used by the MB86681 switch elements to determine the port destination

of the received cell. The validity of the bits in the 20 bit routing field are determined by the programmed

Address Field Size and location parameters as specified in section 3.6.1.

In Figure 10, SRE-L’s (C) and (D) are configured with the parameters:

1. Address Field Size: 3 bits

2. Address Field Location: PA0

3. Column Address : 5-8

Whilst SRE-L’s (A) and (B) are configured with the alternative parameter:

4. Column Address : 1-4

As a result of these configurations ATM Cell 1 passes transparently through SRE-L (A), merely being

re-timed at SRE-L (A)’s R-ports prior to being presented at the corresponding ingress port of SRE-L (C).

CLT 1 CLT 0 Discard Threshold

0 0 No discard

0 1 20% full

1 0 50% full

1 1 80% full

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

In Figure 11 the left most justified bits of the routing field are deemed to be most significant.

SRE-L (C) is configured to analyse the routing field PA0 to PA2. As a result ATM Cell 1 is routed to port

8 of SRE-L (C).

On being routed, the ATM Cell 1 traverses the matrix vertically eventually arriving at SRE-L (D)’s output

port as shown.

Like SRE-L (C), SRE-L (B) is configured to analyse the routing field PA0 to PA2. As a result ATM Cell 2 is

routed to port 3 of SRE-L (B).

The unused routing fields in the 20 bit routing tag may be used to route the cells through numerous stages

prior to further address translation operations being required.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 10 Address Filtering

EP1DT7=L

EP1DT6=H

EP1DT5=L

EP1DT4=L

EP1DT3=L

EP1DT2=L

EPxDTx=L

EP2DT7=L

EP2DT6=L

EP2DT5=L

EP2DT4=L

EP2DT3=L

EP2DT2=L

EP2DT1=L

EP3DT7=L

EP1DT7=L

EP1DT6=H

EP1DT5=L

EP1DT4=L

EP1DT3=L

EP1DT2=L

EPxDTx=L

EP2DT7=L

EP2DT6=L

EP2DT5=H

EP2DT4=L

EP2DT3=L

EP2DT2=L

EP2DT1=L

EP3DT7=L

EP2 EP3 EP4

IP1

IP3

IP4

IP2

RP1

RP2

RP3

RP4

OP1 OP2 OP3 OP4

EP1 EP2 EP3 EP4

IP1

IP3

IP4

IP2

RP1

RP2

RP3

RP4

OP1OP2OP3OP4

EP1

EP2 EP3 EP4

IP1

IP3

IP4

IP2

RP1

RP2

RP3

RP4

OP1 OP2 OP3 OP4

EP1 EP2 EP3 EP4

IP1

IP3

IP4

IP2

RP1

RP2

RP3

RP4

OP1OP2OP3OP4

EP1

SRE-L (A)

ATM CELL1 ~1 0111 0

~011 000

~0111000 ~1 01111 0

2134 5678

BITS 5 -8

BITS 1-4

ATM CELL2

Routing TagCLT M

CRouting TagCLT M

SRE-L (B)

SRE-L (C)

SRE-L (D)

ATM CELL1

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 11 Normal Routing Tag Format

4.1.2 Multicast Routing Tag Control Field Format

The MB86681 switch elements are capable of performing cell replication. The cell replication operation of

the switch elements permits it to transmit a single ATM cell to more than one output port. This operational

mode of cell replication is known as Multicasting.

The Multicasting function is invoked by setting the Multicast Control (MC) bit of the Multicast routing tag as

shown in Figure 12.

The Multicast routing tag illustrated in Figure 12 is comprised of 5 fields. A brief description of the

significance of these fields is now given.

Priority Control (PC) Bit

The Priority Control (PC) bit has exactly the same definition as that described for the normal routing tag in

section 4.1.1.

Multicast Control (MC) Bit

The Multicast Control (MC) bit is used by the MB86681 switch elements to tag the received ATM Cell as a

Multicast cell. This cell will therefore be subject to replication by MB86681 devices configured to carry out

this function.

Relay Link Address Field

The Relay Link Address Field shown in Figure 12 is used as the cell routing field by MB86681 devices not

MCPC CLT1 CLT0 PA0 PA1 PA2 PA17 PA18 PA19

4 bit control ﬁeld 20 bit routing ﬁeld

PA3 PA4

Tag Byte 1 Tag Byte 2 Tag Byte 3

D7 D0 D7 D0

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

configured to carry out the cell replication function indicative of Multicasting.

Devices not configured to carry out cell replication will interpret the Relay Link Address Field as a 5 bit

routing field, with RL4 representing the most significant bit of the field.

The received cell will therefore be treated like a cell with a normal routing tag format and routed to the port

specified in the Relay Link Address Field.

Output Group Select (OGS) Bit

The Output Group Select (OGS) bit is used by the MB86681 elements to determine the band of output ports

over which the received cell may be Multicasted to.

The OGS bit in the Multicast routing tag is only used by MB86681 devices configured to carry out the

Multicast operation.

Multicast Bit mask ﬁeld

The Multicast bit mask field is used to select the desired ports to which a received cell may be Multicasted.

The Multicast bit mask field is only used by MB86681 devices configured to carry out the Multicast

operation.

Figure 12 Routing Tag Format for Multicast operation

RL3 RL2 RL1 RL0 OGS O2

Relay link address

Output Group Select

0: outputs 1 to 16

1: outputs 17 to 32

O12 O13 O14

bit-mask

O16O15O1RL4PC

Multicast Control

0: Normal Operation

1: Multicast

Priority Control

0: low priority

1: high priority

Multicast Tag Format

D0D7

Tag Byte 1

Tag Byte 2 Tag Byte 3

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

4.2 Address Filtering Multicast Operation

The MB86681 Multicast function is invoked by setting the Multicast Control (MC) bit in the received cell’s

routing tag. When this bit is set it changes the way in which the tag field is interpreted.

In Multicast mode the tag is divided into a 16 bit mask field, an output group select field and a relay link

address field. The PC and MC bit positions are unchanged. The multicast routing tag is illustrated in Figure

12.

The following generic description assumes a two stage 64X64 switch comprising four 32X32 matrices, as

shown in Figure 13.

For the purposes of this description, a Multicast server is defined as a matrix comprised of MB86681

devices configured to perform the Multicast operation, i.e cell replication.

Multicast server matrices are constructed from MB86681 devices configured with their Address Location

Field set to zero. Matrices configured in this manner are assumed to provide the primary outputs as shown

in the multi-stage configuration in Figure 13.

In Figure 13 matrices B and D provide the primary outputs and consequently have their Address Location

Field set to zero. As a result matrices B and D are referred to as Multicast servers.

Switch Matrices A and C are configured with MB86681 devices whose Address Location Fields are > 0. As

a result these matrices are referred to as Non-Multicast servers

A description of the Multicast routing mechanism is now explained using the set-up illustrated in Figure 13.

ATM Cell 1 is configured with a Multicast routing tag. This cell is applied to input port 2 of the Non-Multicast

server matrix A.

Matrix A analyses the received cell’s Relay Link Address Field and routes the cell plus appended routing

tag to output port 32.

The routed cell then arrives at input port 1 of the Multicast server matrix D. The receiving MB86681 devices

within the switch matrix will interrogate the OGS bit and bit mask fields of the received cell’s routing tag to

determine if cell replication is necessary.

The bit mask field in conjunction with the OGS bit will determine the outputs to be selected for cell

transmission. A logical ‘1’ in the bit mask field will cause the cell to be forwarded on the corresponding

output port and a logical ‘0’ will cause the cell to be discarded.

This mechanism allows a single primary input cell to be directed to up to 16 primary outputs associated

with a single output group. Hence, for the 64X64 switch illustrated in Figure 13, an input cell may need to

be copied up to 4 times in order to achieve full coverage. The copying process may be performed by the

Fujitsu Network Termination Controller (MB86683X) which will provide sufficient buffering to absorb the

short 4-cell burst.

Thus as shown in Figure 13 ATM Cell 1 is Multicasted to the 16 primary outputs 1 to 16 of the switch matrix

On the other hand ATM Cell 2 is applied to input port 31 of the Non-Multicast server matrix C. The cell is

routed to output port 1 of matrix C, permitting the cell to enter the Multicast server matrix B via input port 32.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

As previously described both the Cell’s OGS and Bit mask fields are interrogated by the MB86681 devices

within matrix B. In Figure 13, ATM Cell 2’s OGS bit is set. This permits the cell to be Multicasted to any of

the output ports 17 to 32. As a result of the bit mask status shown the cell is Multicasted to output ports 17,

31 and 32 of matrix B.

During multicast operation, the user does not have control of the cell loss threshold at which Multicast cells

may be discarded. A default cell loss threshold of 80% is assumed. If no discard is required then the CLP

bit must be set to zero. The user does, however, have control over queue priority. If the PC bit is set to 1

then all relay and multicast operation will use the high priority queues.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 13 Multicast Operation with a 64 x 64 Switch

RELAY

LINK

RELAY

LINK

ATM CELL 1

EP1DT5=L

EP1DT4=L

EP1DT3=L

EP1DT2=H

0108016

PCOGS

CLP=0

111111111111111101111110

EP1DT5=L

EP1DT4=L

EP1DT3=L

EP1DT2=L

EP1DT5=L

EP1DT4=L

EP1DT3=L

EP1DT2=L

EP1DT5=L

EP1DT4=L

EP1DT3=L

EP1DT2=H

Multicast servers

Address Location ﬁeld = 0

Non-multicast servers

Address Location ﬁeld > 0

ATM CELL 2

0108016

OGS

CLP=0

11 10 110000000000000 10000

Non-multicast servers

Address Location ﬁeld > 0 Multicast servers

Address Location ﬁeld = 0

ATM CELL 1 111111111111111101111110

ATM CELL 2 110000000000000110000110

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

4.3 Explicit Forward Congestion Indication (EFCI) function

The MB86681 switch element’s Explicit Forward Congestion Indication (EFCI) function is enabled when

the element’s internal EFCI Enable/Disable Configuration register is set to a logical “1”, as described in

Section 3.6.4.

When enabled, the EFCI function permits Low Priority (LP) cells exiting an output data queue to experience

EFCI marking when the criteria indicating congestion are satisfied.

A LP cell will experience EFCI marking if the MSB of the PTI field in it’s ATM cell header is set to a logic

“0” and the fill level of the output queue from which it is exiting is greater than or equal to the programmed

EFCI threshold configuration register value, as illustrated in Table 2.

When the above criteria for EFCI marking is met, bit 2 of the 3 bit PTI field is set to a logic “1”.

Note:

The MB86681 switch element does not regenerate the ATM Cell header’s HEC field when it alters

the PTI field.

No EFCI marking will be carried out on Cells that have their EFCI Threshold field set to “00”

irrespective of whether the EFCI function has been enabled or not.

Multicast cells satisfying the criteria for EFCI marking are marked when the threshold fill level of

the output data queue from which they exit exceeds or equals the 80% threshold fill level. If

however the Per VC EFCI function, as explained in section 4.4 is enabled, then Multicast cells may

experience EFCI marking at thresholds less than the 80% fill level.

4.4 Per VC EFCI function

When configured to do so, see Section 3.6.7, the MB86681 switch elements permit Per Virtual Circuit (VC)

EFCI marking to be carried out on transmitted cells, when certain programmed/user definable thresholds,

are equalled or exceeded by the output queue fill levels from which the cell emerges.

Enabling the Per VC EFCI function permits the MB86681 switch elements to interpret the 3 byte routing

tag in a manner different from that already mentioned in sections 4.1.1 and 4.1.2.

The interpretation of the 3 byte routing tag is dependant on the type of cell received i.e a normal cell or a

Multicast cell and is detailed in the following paragraphs.

4.4.1 Per VC EFCI implemented on a Normal cell.

A non-Multicast cell, received by an MB86681 switch element with it’s Per VC EFCI Enable / Disable

routing field, PA18 and PA19, and the threshold fill level of the queue from which it exits.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

The EFCI marking function is only implemented when the criteria highlighted in section 4.3 are satisfied.

Figure 14 illustrates the format for the routing tag of a normal ATM Cell permitting Per VC EFCI marking.

Figure 14 Normal Routing Tag permitting Per VC EFCI Marking (EFCIT1 EFCIT0)>0

The user definable EFCI marking Thresholds (EFCIT) should be coded in accordance with the threshold

fill levels indicated in Table 7.

Table 7 Per VC EFCI Marking Threshold Coding

Note:

The MB86681 switch elements will only interpret the routing tag in the manner described when the

Per VC EFCI marking function is enabled.

As with the normal EFCI marking mechanism described in section 4.3, the MB86681 switch

elements do not regenerate the ATM Cell header’s HEC ﬁeld when it alters the PTI ﬁeld.

No Per VC EFCI marking will be carried out on Cells that have their EFCI Threshold field set to “00”

irrespective of whether the Per VC EFCI function has been enabled or not.

However, it should be noticed that EFCI marking may be carried out on the aforementioned cell if

the normal EFCI function is enabled and the conditions for EFCI marking are satisfied.

EFCIT 1 EFCIT 0 EFCI Marking Threshold

0 0 No Per VC Marking

0 1 Output Q 20% full

1 0 Output Q 50% full

1 1 Output Q 80% full

00 CLT1 CLT0 PA0 PA1 PA2 PA17 EFCIT1EFCIT0

4 bit control ﬁeld

PA3 PA4

Tag Byte 1 Tag Byte 2 Tag Byte 3

D7 D0 D7 D0

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

The other fields of the 3 byte routing tag are interpreted in their normal manner as previously

described in section 4.1.1.

4.4.2 Per VC EFCI implemented on a Multicast cell.

The MB86681 switch element provides two Per VC EFCI mechanisms for the marking of Multicast cells.

Both mechanisms are enabled by setting the Per VC EFCI Enable / Disable control register during

initialization. The choice of method used to carry out Per VC EFCI marking on a Multicast cell is dependant

on whether the device is configured as a Multicast server or as a Non Multicast server.

Non-Multicast Server mode.

When an MB86681 switch element is configured as a Non Multicast server it’s Address Field Location

when the most significant bit of the Multicast Cell’s Relay Link Address is set to “1”, as shown in Figure 15,

and the fill level of the Output data queue from which the cell emerges is greater than or equal to the value

programmed into the switch element’s Per VC EFCI Fixed Threshold register.

No Per VC EFCI marking will be carried out on Multicast cells when the Per VC EFCI Fixed Threshold

However, it should be noticed that EFCI marking may be carried out on the aforementioned cell if the

normal EFCI function is enabled and the conditions for EFCI marking are satisfied.

Figure 15 Non-Multicast Server Routing Tag permitting Per VC EFCI Marking

O12 O13 O14 O16O15

RL3 RL2 RL1 RL0 OGS O2O11

Relay link address

Output Group Select

0: outputs 1 to 16

1: outputs 17 to 32

bit-mask

Multicast Control

0: Normal Operation

1: Multicast

Priority Control

0: low priority

1: high priority

Multicast Tag Format

D0D7

Tag Byte 1

Tag Byte 2 Tag Byte 3

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Note:

As with the normal EFCI marking mechanism described in section 4.3, the MB86681 switch

elements do not regenerate the ATM Cell header’s HEC field when it alters the PTI field.

When MB86681 switch elements are configured as Non-Multicast servers with Per VC EFCI marking

enabled, the maximum permissible switch matrix size is 16 X 16.

Multicast Server mode.

When MB86681 switch elements are configured as Multicast servers the Per VC EFCI marking function is

only implemented on Multicast cells when the user definable EFCI Threshold field, as specified by the 2

most significant bits of the normal Relay Link Address field, as shown in Figure 16, is greater than or equal

to the threshold fill level of the Output queue from which the cell emerges.

No Per VC EFCI marking will be carried out on Multicast cells when the Per VC EFCI Threshold field is set

to “00” irrespective of whether the Per VC EFCI function has been enabled or not.

However, it should be noticed that EFCI marking may be carried out on the aforementioned cell if the

normal EFCI function is enabled and the conditions for EFCI marking are satisfied.

The EFCI Threshold field is encoded in accordance with the contents of Table 7.

Figure 16 Multicast Server Routing Tag permitting Per VC EFCI Marking

RL2 RL1 RL0 OGS O2O1EFCIT Field0 1O12 O13 O14 O16O15

Not used

Output Group Select

0: outputs 1 to 16

1: outputs 17 to 32

bit-mask

Multicast Control

0: Normal Operation

1: Multicast

Priority Control

0: low priority

1: high priority

Multicast Tag Format

D0D7

Tag Byte 1

Tag Byte 2 Tag Byte 3

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

4.5 Vertical Flow Control

Unlike it’s predecessor, the MB86680B, the MB86681 provides flow control information for each output

queue. The flow control mechanism permits the implementation of a relatively simple input and output

buffering technique at the edge of the switch matrix whilst at the same time guaranteeing no undesired cell

loss once a cell has been routed.

As outlined earlier in section 2.2, the flow control information is transferred serially to the next vertically

opposite switch element using the VFCI and VFCO pins. Flow control information transmitted on this local

serial highway shall be delimited by SYN characters as defined in CCITT international alphabet No. 5.

Figure 17 shows the per queue flow control format and Figure 18 shows the MB86681 switch element flow

control interconnection for a Master / Slave switch fabric. Identical connections are also used in all Slave

fabrics.

Once enabled, the Output buffer flow control mechanism permits flow control on a cell by cell basis. The

flow control mechanism is activated once the predefined Output queue’s fill level threshold has been

reached, see section 3.6.10 and Table 4. The Output queue’s flow control signal remains in it’s active state

until the Output queue’s fill level falls below the programmed flow control fill level threshold.

On activating the Output queue flow control signal an MB86681 switch element’s vertically opposite

neighbour will cease cell transmission from the corresponding Output data queue until the received Output

queues flow control signal is de-activated.

If an MB86681 switch element receives an active Output queue flow control from it’s vertically opposite

neighbour whilst it is in the process of transmitting a cell to this neighbour, the transmitting switch element

will complete the transmission of the cell before responding to the flow control request.

When configured with a single Output buffer per port, the MB86681 switch element uses the Low priority

queue flow control bits to flow control it’s vertically opposite neighbour.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 17 Flow Control Packet

Figure 18 Serial Flow Control connectivity example

Flow Control Packet

Flow Control Payload

8111 811111 11

Flag HP1 LP1 HP2 LP2 0 HP3 LP3 HP4 LP4 Flag HP1 LP1

Flag = 01111110

HPx = High Priority Queue Status : 0 =Enable cell transfer

1 =Disable cell transfer

LPx = Low Priority Queue Status : 0 =Enable cell transfer

Disable cell transfer

EPCLK EP1 EP4

IPCLK

VFCO

VFCI

EPCLK EP1 EP4

IPCLK

VFCO

VFCI

EPCLK EP1 EP4

IPCLK

VFCO

VFCI

MASTER

Switch Element

VSS unused

Slave

Switch Element

Slave

Switch Element

CLK

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

4.6 Early Packet Discard Notiﬁcation.

The MB86681 switch element provides Early Packet Discard (EPD) notification ports. The 4 EPD ports

permit direct communication with EPD mechanisms operating at the ingress side of the switch fabric.

The EPD notification takes the form of an active low transition on the respective EPD port. An active low

transition on an EPD port will result when either a selective cell discard or buffer overflow condition results

on a cell currently being received at one of the MB86681’s I-input ports.

Figure 19 EPD1 Bus connectivity

When a cell currently being received on a switch element’s I1 input port is discarded, the respective EPD

port, namely, EPD1, is driven to it’s active low position for the duration of one IPCLK clock period.

The 4 tristate EPD ports permit bus connectivity across the row of a switch fabric as shown in Figure 19.

EPD notification will take place within 20 IPCLK clock cycles from the cell data first being presented to an

MB86681’s I-input port. As a consequence the discarding of a cell can be notified before the full cell has

been received by the MB86681 switch element.

Transitions on the EPD ports take place with respect to the rising edge of the IPCLK clock signal.

EPD1

EPD2

EPD3

EPD4

R-Ports

I-Ports

I-Ports R-Ports

EPD1

EPD2

EPD3

EPD4

EPD1 Bus Row A

EPD1

EPD2

EPD3

EPD4

R-Ports

I-Ports

I-Ports R-Ports

EPD1

EPD2

EPD3

EPD4

EPD1 Bus Row B

Switch Fabric

O-Ports

O-Ports O-Ports

O-Ports

E-Ports E-Ports

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

4.7 JTAG

4.7.1 Introduction

This device contains Boundary Scan Test Circuitry compliant with IEEE 1149.1 (JTAG). This requires the

addition of the 5 pins identified below. See Appendix C for a full BSDL description.

The JTAG circuitry allows easier board level testing by allowing the signal pins on the device to form a

serial scan chain around the device. The test modes are controlled by accessing an internal Test Access

Port Controller (TAP), which is in turn controlled from the TAP.

4.7.2 Test Access Port (TAP)

Five pins are dedicated to JTAG:TDO; TDI; TMS; TRST & TCK.

The functions of these signals are described in Section 2.2 of this datasheet.

4.8 Test Instructions

The following JTAG instructions are implemented:- BYPASS

SAMPLE/PRELOAD

EXTEST

INTEST.

BYPASS

The BYPASS instruction is used to bypass a component that is connected in series with other components.

This allows more rapid movement of test data through the components of the board, bypassing the ones

that do not need to be tested. The BYPASS operation enables the bypass register, which is a single stage

shift register, between TDI and TDO

1. The binary code for the BYPASS instruction is “11”.

2. The BYPASS instruction is forced into the instruction register output latches during the

Test_Logic_Reset state. Note the distinction between the “01” content of the instruction shift register

and the “11” of the instruction register output latch. Therefore , at the start of the instruction-shift cycle,

a “01” pattern will be seen instead of “11”.

3. The BYPASS operation does not interfere with the component operation at all. If the TDI input trace to

the component is somehow disconnected, the test logic will see a “11” at TDI input during the instruc-

tion-shift state. Therefore, no unwarranted interference with the on-chip system logic occurs.

SAMPLE/PRELOAD

The SAMPLE/PRELOAD instruction is used to sample the state of the component pins. The sampled

values can be examined by shifting out the data through TDO. This instruction selects the boundary scan-

cell output latches with specific values. The preloaded values are then enabled to the output pins by the

EXTEST.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

1. The binary code for the instruction is “01”.

2. The SAMPLE/PRELOAD instruction selects the boundary-scan cells to be connected between TDI

and TDO in the Shift_DR TAP controller state

3. The values of the component pins are sampled on the rising edge of TCK in the Capture_DR TAP

controller state.

4. The preload values shifted in the boundary scan cells are latched into the boundary-scan output latch

at the falling edge of TCK in the Update_DR TAP controller state.

EXTEST

The EXTEST instruction allows testing of off-chip circuitry and board level interconnections. The

PRELOAD /SAMPLE instruction is used to preload the data into the latched parallel outputs of the

boundary-scan shift register stages. Then, the EXTEST instruction enables the preloaded values to the

components output pins.

1. The binary code for the instruction is “00”.

2. The device outputs the preloaded data to the pins at the falling edge of TCK in the Update_IR TAP

controller state at which point the JTAG instruction register is updated with the EXTEST.

3. The EXTEST instr uction selects the boundary-scan cells to be connected between TDI and TDO in

the SHIFT-DR test logic controller state.

4. Once the EXTEST instruction is eff ectiv e , the output pins can change at the f alling edge of TCK in the

Update_DR TAP controller state.

INTEST

This instruction allows testing of the on-chip system logic. Test stimuli are shifted in, one at a time, and

applied to the on-chip logic. The test results are captured into the boundary scan register (BSR) and are

examined by subsequent shifting. The PRELOAD/SAMPLE instruction is used to preload the data into the

latched parallel outputs of the boundary-scan shift register stages prior to INTEST being selected.

The binary code for the instruction is “10”.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

5 Developers Notes

5.1 External Interfaces

External interfaces of the switch element are illustrated in Figure 3 and are described in the following

paragraphs.

5.1.1 ATM Cell Structure

The structure of an ATM cell is illustrated in Figure 20. The only bit in the cell that is processed by the

MB86681 switch element is the CLP bit. This bit is used to determine whether a cell should be discarded

when the output queue fill level exceeds a programmable threshold.

Note: When EFCI functions are disabled, none of the bits in an ATM cell will be modified by the MB86681

switch elements. The switch elements will not discard idle cells; it is assumed that idle cells will be

discarded before data is applied to the switch (e.g. by the FUJITSU Network Termination Controller).

5.1.2 External Data Structure

All input/output data for the MB86681 switch elements is comprised of 8 data bits together with a Start of

Cell (SOC) bit and a clock signal. The data for one cell period comprises a 3 byte tag field followed by a 53

byte ATM cell. The cell stream may be continuous or discontinuous.

In both cases the SOC bit marks the first tag byte associated with a cell period. The clock rate should be

selected to be as close as possible to 56/53 X ATM cell data rate. For SDH STM-1 applications a value of

155.52MHz / 8 provides a good match.

A diagram of the external data interface format for both Fujitsu Cell Steam (FCS) and the Inverse FCS

(IFCS) modes of operation is illustrated in Figure 21.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 20 ATM Cell Header Structure

VPI

VPI VCI

VCI

VCI PTI CLP

HEC

CELL PAYLOAD

VPI / GFC

5 byte cell header

GFC = Generic Flow Control

VPI = Virtual Path Identiﬁer

VCI = Virtual Channel Identiﬁer

PTI = Payload Type Indicator

CLP = Cell Loss Priority

HEC = Header Error Control

48 byte payload for user data

bytes

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 21 Cell Stream Transmission Timing

56 clock cycles idle period

(n clock cycles,

n > or = 0)

Tag (3 bytes) ATM Cell (53 bytes) Tag (3 bytes)

IPCLK

OPxSOC

OPxD0-7

56 clock cycles idle period

(n clock cycles,

n > or = 0)

Tag (3 bytes) ATM Cell (53 bytes) Tag (3 bytes)

IPCLK

OPxSOC

OPxD0-7

a) Fujitsu Cell Stream Format

b) Inverse Fujitsu Cell Stream Format

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

A Electrical Speciﬁcation

A.1 Absolute Maximum Ratings

A.2 Recommended Operating Conditions

Parameter Symbol Values Units

Min Max

Positive Supply Voltage +VD5 VSS-0.5 6.0 V

Positive Supply Voltage +VD3 VSS-0.5 4.0 V

Input Voltage VDIN VSS-0.5 VD5+0.5 V

Output Voltage VO1 VSS-0.5 VD5+0.5 V

Storage Temperature TSTG -55 +125 oC

Operating Temperature TA0 +70 oC

Parameter Symbol Ratings Units

Min Typ. Max

Positive Supply Voltage (for 5V interface) +VD5 4.5 5.0 5.5 V

Positive Supply Voltage (for 3V interface) +VD3 3.0 3.3 3.6 V

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

A.3 DC Characteristics

Parameter Symbol Test

Condition Ratings Units

Min Typ. Max

Positive Supply Current IDDS Static no load -2.0 - 2.0 mA

Input High Voltage (TTL) VIH - VD3x0.65 - VD5 V

Input Low Voltage (TTL) VIL - VSS - VD3x0.2 V

Low Level Output Voltage VOL IOL=+4.0mA

IOH=-4.0mA VSS - 0.4 V

High Level Output Voltage VOH VD3-0.5 - VD5 V

Input Leakage Current ILI 0<=Vi<=VD5 -5 - 5 µA

Input/Output Pin Capacitance CIN/OUT - - - 18 pF

Operating Current (normal) IDD3 - - - 310 mA

IDD5 60 mA

Power Dissipation (operating) PO3 - - - 1.03 W

PO5 0.33 W

Recommended Operating Conditions

Recommended operating conditions are normal operating ranges for the semiconductor device. All the device’s

electrical characteristics are warranted when operated within these ranges.

Always use semiconductor devices within the recommended operating conditions. Operation outside these ranges

may adversely affect reliability and could result in device failure.

No warranty is made with respect to uses , operating conditions, or combinations not represented on the data

sheet. Users considering application outside the listed conditions are advised to contact their FUJITSU

representative beforehand.

Absolute Maximum Ratings

Semiconductor devices can be permanently damaged by application of stress (voltage, current, temperature, etc.)

in excess of absolute maximum ratings. Do not exceed these ratings.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

B AC Characteristics

Figure 22 Reset Timing

Table 8 Reset AC Timing Parametrics

Figure 23 Input Clock Timing

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

Reset Pulse Width RESET tRST 7 - - ns

RESET

tRST

IPCLK

EPCLK

tCKW

tICKL

tECKL

tICKH

tECKH

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Table 9 IPCLK/EPCLK AC Timing Parameters

Figure 24 I-Input Port Timing

Table 10 I-Input Port AC Timing Parameters

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

IPCLK High time IPCLK tICKH 8 - - ns

EPCLK High time EPCLK tECKH 8 - - ns

IPCLK Low time IPCLK tICKL 8 - - ns

EPCLK Low time EPCLK tECKL 8 - - ns

IP/EPCLK Frequency tCKW - - 40 MHz

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

IPXSOC Data Setup Time IPCLK tISS 2 - - ns

IPXSOC Data Hold Time IPCLK tISH 3 - - ns

IPXD7..D0 Data Setup Time IPCLK tIDS 2 - - ns

IPXD7..D0 Data Hold Time IPCLK tIDH 3 - - ns

tISH

tISS

IPCLK

IPXD7..D0

IPXSOC

Input Data Input Data Input DataInput Data

tIDH

tIDS

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 25 E-Input Port Timing

Table 11 E-Input Port AC Timing Parameters

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

EPXSOC Data Setup Time EPCLK tESS 3 - - ns

EPXSOC Data Hold Time EPCLK tESH 2 - - ns

EPXD7..D0 Data Setup Time EPCLK tEDS 3 - - ns

EPXD7..D0 Data Hold Time EPCLK tEDH 2 - - ns

tESS tESH

EPCLK

EPXD7..D0

EPXSOC

Input Data Input Data Input DataInput Data

tEDH

tEDS

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 26 Output Port Timing-FCS

Table 12 Output Port FCS Mode AC Timing Parameters

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

OPXSOC output delay IPCLK tFOPS 3 - 20 ns

OPXD7..D0 output delay IPCLK tFOPD 5 - 20 ns

RPXSOC output delay IPCLK tFRPS 3 - 20 ns

RPXD7..D0 output delay IPCLK tFRPD 3 - 20 ns

OPXD7..D0

IPCLK

Output Data Output Data Output DataOutput Data

OPXSOC

RPXD7..D0

IPCLK

Output Data Output Data Output DataOutput Data

RPXSOC

tFOPS

tFOPD

tFRPS

tFRPD

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 27 Output Port Timing-IFCS Mode

Table 13 Output Port IFCS Mode AC Timing Parameters

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

OPXSOC output delay IPCLK tIOPS 4 - 20 ns

OPXD7..D0 output delay IPCLK tIOPD 4 - 20 ns

RPXSOC output delay IPCLK tIRPS 3 - 20 ns

RPXD7..D0 output delay IPCLK tIRPD 3 - 20 ns

OPXD7..D0

IPCLK

Output Data Output Data Output DataOutput Data

OPXSOC

RPXD7..D0 Output Data Output Data Output DataOutput Data

RPXSOC

tIOPS

tIOPD

tIRPS

tIRPD

IPCLK

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 28 INIT Port Timing

Table 14 INIT Port AC Timing Parameters

Figure 29 EPD Port Timing

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

INITIN Data Setup Time IPCLK tIDS 1 - - ns

INITIN Data Hold Time IPCLK tIDH 2 - - ns

INITOUT Output Delay IPCLK tID 3 - 20 ns

tIDH

tIDS

tID

IPCLK

INITIN

INITOUT

IPCLK

Output Data Output Data Output DataOutput Data

Input Data Input Data Input DataInput Data

tEDZL

IPCLK

EPDx High Z High Z

tEDLZ

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Table 15 EPD Port AC Timing Parameters

Figure 30 Vertical Flow Control Port Timing

Table 16 Vertical Flow Control Port AC Timing Parameters

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

EPD Port Delay (Z-L) IPCLK tEDZL 3 - 18 ns

EPD Port Delay (L-Z) IPCLK tEDLZ 8 - 20 ns

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

VFCI Data Setup Time IPCLK tFDS 4 - - ns

VFCI Data Hold Time IPCLK tFDH 1 - - ns

VFCO Out Delay IPCLK tFD 4 - 18 ns

VFCI

tFDH

tFDS

tFD

IPCLK

VFCO

IPCLK

Output Data Output Data Output DataOutput Data

Input Data Input Data Input DataInput Data

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Figure 31 JTAG Port TRST Timing

Table 17 JTAG TRST AC Parameters

Figure 32 JTAG Port Timing

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

JTAG TRST Pulse Width TRST tTRST 10 - - ns

TRST

tTRST

tJMDS tJMDH

tJIDH

tJIDS

tJTD

TCK

TMS

TDI

TDO

TCK

Output Data Output Data Output DataOutput Data

Input Data Input Data Input DataInput Data

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Table 18 JTAG Port AC Timing Parameters

NOTE:

All timings are characterized over the temperature range 00 to 700 Centigrade for device operation up to

and including 40MHz.

Parameter Ref.

Signal Abbrev. Values Units

Min Typical Max

JTAG TMS Data Setup Time TCK tJMDS 0 - - ns

JTAG TMS Data Hold Time TCK tJMDH 1 - - ns

JTAG TDI Data Setup Time TCK tJIDS 0 - - ns

JTAG TDI Data Hold Time TCK tJIDH 3 - - ns

JTAG TDO Out Delay TCK tJTD 3 - 20 ns

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

C JTAG Boundary Scan Description

A BSDL description for the MB86681 may be downloaded from the following web site :

http://www.fml.co.uk/

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

D Pin Assignments

D.1 Pin Diagram

Figure 33 MB86681 Pin Assignment

EPD1

EPD2

RP1SOC

RP1DT7

VSS

RP1DT6

RP1DT5

RP1DT4

TRST

RP1DT3

VD3

RP1DT2

RP1DT1

RP1DT0

RP2SOC

VSS

RP2DT7

RP2DT6

RP2DT5

EPD3

RP2DT4

RP2DT2

RP3SOC

RP3DT7

RP3DT6

RP3DT5

VSS

EPD4

RP3DT4

RP3DT2

RP3DT1

VD3

RP3DT0

RP4DT7

RP4DT6

RP4DT5

RP4DT4

VSS

VD3

RP2DT1

RP2DT0

RP2DT3

VD3

RP4SOC

RP3DT3

RP4DT2

RP4DT3

RP4DT0

TMS

RP4DT1

TDI

VSS

IP1SOC

IP1DT7

IP1DT6

VSS

IP1DT5

IP1DT4

INITIN

IP1DT2

IP1DT1

VD3

IP2DT5

VD3

IP2DT2

IP2DT0

VSS

IP1DT0

IP2DT7

IP2DT6

INITOUT

IP2DT4

IP2DT3

IP2DT1

IP3DT7

IP3DT5

VD3

VSS

IP3DT3

IP3DT2

IP3DT0

IP4SOC

VD3

IP4DT7

IP4DT5

IP4DT4

IP4DT3

IP4DT2

VSS

IP4DT1

IP4DT0

TST3

TST2

OP1DT7

OP1DT6

OP1DT5

OP1DT4

OP1DT3

OP1DT2

OP1DT1

OP1DT0

VFCI

OP2SOC

OP2DT7

OP2DT6

OP2DT5

OP2DT4

VSS

EP2DT3

EP2DT2

EP2DT1

VSS

EP3DT7

OP4DT7

OP4DT6

OP4DT5

OP4DT4

OP4DT3

OP4DT2

OP3DT0

EP3DT6

TST5

OP3DT4

VSS

OP3DT3

OP3DT2

OP3DT1

VD3

VD5

TST4

EP1SOC

EPCLK

EP1DT7

EP1DT6

VSS

EP1DT5

EP1DT4

EP1DT3

EP1DT2

EP1DT1

VD3

EP1DT0

OP2DT3

VFCO

OP2DT1

VSS

VD3

EP2SOC

EP2DT7

EP2DT6

EP2DT5

VSS

EP3DT4

EP3DT3

EP3DT2

VD3

VSS

EP3DT0

OP3SOC

OP3DT6

OP3DT5

VD5

EP4SOC

EP4DT7

EP4DT6

EP4DT5

EP4DT4

EP4DT3

EP4DT2

EP4DT1

EP4DT0

TDO

EP3DT5

1 26 52

105130156

157

182

208

104

VD5

OP4SOC

VSS

OP4DT1

OP4DT0

EP2DT0

RESET

TST1

VD3

IP3DT1

IP4DT6

IP2SOC

VD3

IP1DT3

IP3SOC

IP3DT6

TCK

EP2DT4

OP2DT0

OP2DT2

VSS

VD5

VSS

OP3DT7

EP3DT1

OP1SOC

IP3DT4

IPCLK

VSS

VD3

EP3SOC

MB86681

SRE-L

(TOP VIEW)

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

D.2 Pin Assignment

Pin No. Pin Name Type Function

1 OP1SOC O(5.0V) Output Port1, Start Of Cell

2 OP1DT7 O(5.0V) Output Port1, bit D7 (MSB)

3 VSS -

4 OP1DT6 O(5.0V) Output Port1, bit D6

5 OP1DT5 O(5.0V) Output Port1, bit D5

6 OP1DT4 O(5.0V) Output Port1, bit D4

7 OP1DT3 O(5.0V) Output Port1, bit D3

8 OP1DT2 O(5.0V) Output Port1, bit D2

9 OP1DT1 O(5.0V) Output Port1, bit D1

10 VD5 -

11 OP1DT0 O(5.0V) Output Port1, bit D0

12 VFCI I Vertical Flow Control Input Port

13 OP2SOC O(5.0V) Output Port2, Start Of Cell

14 OP2DT7 O(5.0V) Output Port2, bit D7 (MSB)

15 VSS -

16 OP2DT6 O(5.0V) Output Port2, bit D6

17 OP2DT5 O(5.0V) Output Port2, bit D5

18 OP2DT4 O(5.0V) Output Port2, bit D4

19 VD3 -

20 EP2DT3 I Expansion Port2, bit D3

21 EP2DT2 I Expansion Port2, bit D2

22 EP2DT1 I Expansion Port2, bit D1

23 EP2DT0 I Expansion Port2, bit D0

24 VSS -

25 RESET I Reset

26 VSS -

27 VD3 -

28 TST1 I Reserved Test Input pin-Connect to VSS

29 VSS -

30 EP3SOC I Expansion Port3, Start Of Cell

31 EP3DT7 I Expansion Port3, bit D7 (MSB)

32 EP3DT6 I Expansion Port3, bit D6

33 EP3DT5 I Expansion Port3, bit D5

34 VD3 -

35 TST5 O(5.0V) Reserved Test Output pin

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

36 OP3DT4 O(5.0V) Output Port3, bit D4

37 OP3DT3 O(5.0V) Output Port3, bit D3

38 VSS -

39 OP3DT2 O(5.0V) Output Port3, bit D2

40 OP3DT1 O(5.0V) Output Port3, bit D1

41 OP3DT0 O(5.0V) Output Port3, bit D0

42 OP4SOC O(5.0V) Output Port4, Start Of Cell

43 VD5 -

44 OP4DT7 O(5.0V) Output Port4, bit D7 (MSB)

45 OP4DT6 O(5.0V) Output Port4, bit D6

46 OP4DT5 O(5.0V) Output Port4, bit D5

47 OP4DT4 O(5.0V) Output Port4, bit D4

48 OP4DT3 O(5.0V) Output Port4, bit D3

49 OP4DT2 O(5.0V) Output Port4, bit D2

50 VSS -

51 OP4DT1 O(5.0V) Output Port4, bit D1

52 OP4DT0 O(5.0V) Output Port4, bit D0

53 TDI I JTAG Test Data Input

54 TMS I JTAG Test Mode Select

55 RP4DT0 O(3.0V) Regeneration Port4, bit D0

56 RP4DT1 O(3.0V) Regeneration Port4, bit D1

57 RP4DT2 O(3.0V) Regeneration Port4, bit D2

58 RP4DT3 O(3.0V) Regeneration Port4, bit D3

59 RP4DT4 O(3.0V) Regeneration Port4, bit D4

60 VSS -

61 VD3 -

62 RP4DT5 O(3.0V) Regeneration Port4, bit D5

63 RP4DT6 O(3.0V) Regeneration Port4, bit D6

64 RP4DT7 O(3.0V) Regeneration Port4, bit D7 (MSB)

65 RP4SOC O(3.0V) Regeneration Port4, Start Of Cell

66 RP3DT0 O(3.0V) Regeneration Port3, bit D0

67 RP3DT1 O(3.0V) Regeneration Port3, bit D1

68 RP3DT2 O(3.0V) Regeneration Port3, bit D2

69 RP3DT3 O(3.0V) Regeneration Port3, bit D3

70 RP3DT4 O(3.0V) Regeneration Port3, bit D4

71 EPD4 OT(3.0V) Tristate I4 Input Port EPD signal

72 VSS -

73 VD3 -

Pin No. Pin Name Type Function

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

74 RP3DT5 O(3.0V) Regeneration Port3, bit D5

75 RP3DT6 O(3.0V) Regeneration Port3, bit D6

76 RP3DT7 O(3.0V) Regeneration Port3, bit D7 (MSB)

77 RP3SOC O(3.0V) Regeneration Port3, Start Of Cell

78 RP2DT0 O(3.0V) Regeneration Port2, bit D0

79 VD3 -

80 RP2DT1 O(3.0V) Regeneration Port2, bit D1

81 RP2DT2 O(3.0V) Regeneration Port2, bit D2

82 RP2DT3 O(3.0V) Regeneration Port2, bit D3

83 RP2DT4 O(3.0V) Regeneration Port2, bit D4

84 EPD3 OT(3.0V) Tristate I3 Input Port EPD signal

85 VSS -

86 VD3 -

87 RP2DT5 O(3.0V) Regeneration Port2, bit D5

88 RP2DT6 O(3.0V) Regeneration Port2, bit D6

89 RP2DT7 O(3.0V) Regeneration Port2, bit D7 (MSB)

90 RP2SOC O(3.0V) Regeneration Port2, Start Of Cell

91 RP1DT0 O(3.0V) Regeneration Port1, bit D0

92 RP1DT1 O(3.0V) Regeneration Port1, bit D1

93 RP1DT2 O(3.0V) Regeneration Port1, bit D2

94 RP1DT3 O(3.0V) Regeneration Port1, bit D3

95 TRST I JTAG Test Reset

96 VSS -

97 VD3 -

98 RP1DT4 O(3.0V) Regeneration Port1, bit D4

99 RP1DT5 O(3.0V) Regeneration Port1, bit D5

100 RP1DT6 O(3.0V) Regeneration Port1, bit D6

101 RP1DT7 O(3.0V) Regeneration Port1, bit D7 (MSB)

102 RP1SOC O(3.0V) Regeneration Port1, Start Of Cell

103 EPD2 OT(3.0V) Tristate I2 Input Port EPD signal

104 EPD1 OT(3.0V) Tristate I1 Input Port EPD signal

105 TDO OT(5.0V) Tristate JTAG Test Data Output

106 EP4DT0 I Expansion Port4, bit D0

107 VSS -

108 EP4DT1 I Expansion Port4, bit D1

109 EP4DT2 I Expansion Port4, bit D2

110 EP4DT3 I Expansion Port4, bit D3

111 EP4DT4 I Expansion Port4, bit D4

Pin No. Pin Name Type Function

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

112 EP4DT5 I Expansion Port4, bit D5

113 EP4DT6 I Expansion Port4, bit D6

114 VD5 -

115 EP4DT7 I Expansion Port4, bit D6 (MSB)

116 EP4SOC I Expansion Port4, Start Of Cell

117 OP3DT5 O(5.0V) Output Port3, bit D5

118 OP3DT6 O(5.0V) Output Port3, bit D6

119 VSS -

120 OP3DT7 O(5.0V) Output Port3, bit D7 (MSB)

121 OP3SOC O(5.0V) Output Port3, Start Of Cell

122 EP3DT0 I(5.0V) Expansion Port3, bit D0

123 VD3 -

124 EP3DT1 I Expansion Port3, bit D1

125 EP3DT2 I Expansion Port3, bit D2

126 EP3DT3 I Expansion Port3, bit D3

127 EP3DT4 I Expansion Port3, bit D4

128 VSS -

129 EPCLK I Expansion Port Clock

130 VSS -

131 VD3 -

132 TCK I JTAG Test Clock

133 EP2DT4 I Expansion Port2, bit D4

134 EP2DT5 I Expansion Port2, bit D5

135 EP2DT6 I Expansion Port2, bit D6

136 EP2DT7 I Expansion Port2, bit D7 (MSB)

137 EP2SOC I Expansion Port2, Start Of Cell

138 VD3 -

139 OP2DT0 O(5.0V) Output Port2, bit D0

140 OP2DT1 O(5.0V) Output Port2, bit D1

141 OP2DT2 O(5.0V) Output Port2, bit D2

142 VSS -

143 OP2DT3 O(5.0V) Output Port2, bit D3

144 VFCO O(5.0V) Vertical Flow Control Output Port

145 EP1DT0 I Expansion Port1, bit D0

146 EP1DT1 I Expansion Port1, bit D1

147 VD5 -

148 EP1DT2 I Expansion Port1, bit D2

Pin No. Pin Name Type Function

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

149 EP1DT3 I Expansion Port1, bit D3

150 EP1DT4 I Expansion Port1, bit D4

151 EP1DT5 I Expansion Port1, bit D5

152 EP1DT6 I Expansion Port1, bit D6

153 EP1DT7 I Expansion Port1, bit D7 (MSB)

154 VSS -

155 EP1SOC I Expansion Port1, Start Of Cell

156 TST4 O(5.0V) Reserved Test Output pin

157 VSS -

158 VSS -

159 IP1SOC I Input Port1, Start Of Cell

160 IP1DT7 I Input Port1, bit D7 (MSB)

161 IP1DT6 I Input Port1, bit D6

162 IP1DT5 I Input Port1, bit D5

163 IP1DT4 I Input Port1, bit D4

164 VSS -

165 VD3 -

166 INITIN I Initialization Input Port

167 IP1DT3 I Input Port1, bit D3

168 IP1DT2 I Input Port1, bit D2

169 IP1DT1 I Input Port1, bit D1

170 IP1DT0 I Input Port1, bit D0

171 IP2SOC I Input Port2, Start Of Cell

172 IP2DT7 I Input Port2, bit D7

173 IP2DT6 I Input Port2, bit D6

174 IP2DT5 I Input Port2, bit D5

175 INITOUT O(3.0V) Initialization Output Port

176 VSS -

177 VD3 -

178 IP2DT4 I Input Port2, bit D4

179 IP2DT3 I Input Port2, bit D3

180 IP2DT2 I Input Port2, bit D2

181 IP2DT1 I Input Port2, bit D1

182 IP2DT0 I Input Port2, bit D0

183 VD3 -

184 IP3SOC I Input Port3, Start Of Cell

185 IP3DT7 I Input Port3, bit D7

186 IP3DT6 I Input Port3, bit D6

Pin No. Pin Name Type Function

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

187 IP3DT5 I Input Port3, bit D5

188 IPCLK I Input Port Clock

189 VSS -

190 VD3 -

191 IP3DT4 I Input Port3, bit D4

192 IP3DT3 I Input Port3, bit D3

193 IP3DT2 I Input Port3, bit D2

194 IP3DT1 I Input Port3, bit D1

195 IP3DT0 I Input Port3, bit D0

196 IP4SOC I Input Port4, Start Of Cell

197 IP4DT7 I Input Port4, bit D7

198 IP4DT6 I Input Port4, bit D6

199 IP4DT5 I Input Port4, bit D5

200 VSS -

201 VD3 -

202 IP4DT4 I Input Port4, bit D4

203 IP4DT3 I Input Port4, bit D3

204 IP4DT2 I Input Port4, bit D2

205 IP4DT1 I Input Port4, bit D1

206 IP4DT0 I Input Port4, bit D0

207 TST3 I Reserved Test Input pin-Connect to VSS

208 TST2 I Reserved Test Input pin-Connect to VSS

Pin No. Pin Name Type Function

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

E Package Dimensions

(0.15 ± 0.05)

.006 ±.002

.0197 (0.50)

TYP

.006 (0.15) MAX

(0.50 ± 0.20)

.020 ±.008

+.003

-.001

+0.08

-0.03 .003 (0.08)

LEAD No.

.016 (0.40) MAX

FPT-208P-M04

Dimensions in

inches (millimetres)

208-LEAD PLASTIC FLAT PACKAGE

(CASE No.: FPT-208P-M04)

1996 FUJITSU LIMITED

156

157

208

104

105 .010 (0.25) MIN

(STAND OFF HEIGHT)

1.102 ±.004

(28.00 ±0.10)

(MOUNTING HEIGHT)

.155 (3.95) MAX

1.205 ±.008

(30.60 ±0.20)

INDEX “A”

.008 (0.20)

.010 (0.25)

1.004 (25.50)

REF

.004 (0.10)

“B”

1.165”.006

(29.60”0.15)

NOM

(0.20 M

0° to 10°

)

Details of “B” partDetails of “A” part

.008

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Revision Control

Revision

Number Date

DD/MM/YY Description of the Changes

0.8 11/09/96 Minor syntax corrections made to JTAG BSDL descr iption in Appendix

Correction to the Back page Revision Control Number.

0.9 21/02/97 Non Characterized AC Parametrics and updated diagrams added

1.0 11/03/97 Characterized AC Parametrics and updated diagrams added

1.1 19/11/97 AC & DC Parametrics sections altered.

The contents of this document are subject to change without notice. Customers are advised to consult with

FUJITSU sales representatives before ordering.

The information and circuit diagrams in this document presented as examples of semiconductor device

applications, and are not intended to be incorporated in devices for actual use. Also, FUJITSU is unable to assume

responsibility for infringement of any patent rights or other rights of third parties arising from the use of this

information or circuit diagrams.

FUJITSU semiconductor devices are intended for use in standard applications (computers, office automation and

other office equipment, industrial, communications, and measurement equipment, personal or household devices,

etc.). CAUTION: Customers considering the use of our products in special applications where failure or abnormal

operation may directly affect human lives or cause physical injury or property damage, or where extremely high

levels of reliability are demanded (such as aerospace systems, atomic energy controls, sea floor repeaters, vehicle

operating controls, medical devices for life support, etc.) are requested to consult with FUJITSU sales

representatives before such use. The company will not be responsible for damages arising from such use without

prior approval.

Any semiconductor devices have inherently a certain rate of failure. You must protect against injury, damage or

loss from such failures by incorporating safety design measures into your facility and equipment such as

redundancy, fire protection, and prevention of over-current levels and other abnormal operating conditions.

If any products described in this document represent goods or technologies subject to certain restrictions on export

under the Foreign Exchange and Foreign Trade Control Law of Japan, the prior authorization by Japanese

government should be required for export of those products from Japan.

December 1997 Version 1.1

FML/NPD/SRE-L/DS/1223

MB86681 ATM Switch Element (SRE-L)

Worldwide Headquarters

Japan Asia

Tel: +81 44 754 3753

Fax: +81 44 754 3332

Fujitsu Limited

1015 Kamiodanaka

Nakaharaku

Kawasaki 211

Japan

Tel: +65 336 1600

Fax: +65 336 1609

Fujitsu Microelectronics Asia

PTE Limited

No. 51 Bras Basah Road

Plaza by the Park

#06-04/07

Singapore 0718

http://www.fujitsu.co.jp/

http://www.fsl.com.sg/

USA Europe

Tel: +1 408 922 9000

Fax: +1 408 922 9179

Fujitsu Microelectronics Inc

3545 North First Street

San Jose CA 95134-1804

USA

Tel: +49 6103 6900

Fax: +49 6103 690122

Fujitsu Mikroelektronik GmbH

Am Siebenstein 6-10

D-63303 Dreieich-Buchschlag

Germany

Tel: +1 800 866 8608

Fax: +1 408 922 9179

Customer Response Center

Mon-Fri: 7am-5pm (PST)

http://www.fujitsumicro.com/ http://www.fujitsu-ede.com/

FML/NPD/SRE-L/DS/1223 - 1.1