KS8995MA/FQ
Integrated 5-Port 10/100 Managed Switch
Rev 2.9
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
September 2008 M9999-091508
General Description
The KS8995MA/FQ is a highly integrated Layer 2
managed switch with optimized bill of materials (BOM)
cost for low port count, cost-sensitive 10/100Mbps
switch systems with both copper and optic fiber media.
It also provides an extensive feature set such as
tag/port-based VLAN, quality of service (QoS) priority,
management, MIB counters, dual MII interfaces and
CPU control/data interfaces to effectively address both
current and emerging fast Ethernet applications.
The KS8995MA/FQ contains five 10/100 transceivers
with patented mixed-signal low-power technology, five
media access control (MAC) units, a high-speed non-
blocking switch fabric, a dedicated address lookup
engine, and an on-chip frame buffer memory.
All PHY units support 10BASE-T and 100BASE-TX.
In addition, two of the PHY units support 100BASE-FX
(KS8995MA is ports 4 and 5, KS8995FQ is port 3 and
port 4).
Functional Diagram
Micrel, Inc. KS8995MA/FQ
Semptember 2008 2 M9999-091508
1K Look Up
Engine
Queue
Mgmnt
10/100
MAC 1
Buffer
Mgmnt
Frame
Buffers
FIFO, Flow Control, VLAN Tagging, Priority
10/100
MAC 2
10/100
MAC 3
10/100
MAC 4
10/100
MAC 5
SNI
10/100
T/Tx 1
10/100
T/Tx 2
10/100
T/Tx/Fx 3
10/100
T/Tx/Fx 4
10/100
T/Tx 5
SPI
EEPROM
I/F
LED I/F
Auto
MDI/MDIX
Control Reg I/F
MIB
Counters
MII- SW or SNI
LED0[5:1]
LED1[5:1]
LED2[5:1] Control
Registers
MII-P5
MDC, MDI/O
Auto
MDI/MDIX
Auto
MDI/MDIX
Auto
MDI/MDIX
Auto
MDI/MDIX
KSZ8995FQ
Notes:
1. KS8995MA has either TX copper or FX fiber for port 4 and port 5, other ports are the TX copper only.
2. KS8995FQ has either TX copper or FX fiber for port 3 and port 4, other ports are the TX copper only.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 3 M9999-091508
Features
• Integrated switch with five MACs and five fast
Ethernet transceivers fully compliant to IEEE 802.3u
standard
• Shared memory based switch fabric with fully non-
blocking configuration
• 1.4Gbps high-performance memory bandwidth
• 10BASE-T, 100BASE-TX, and 100BASE-FX modes
• Dual MII configuration: MII-Switch (MAC or PHY
mode MII) and MII-P5 (PHY mode MII)
• IEEE 802.1q tag-based VLAN (16 VLANs, full-range
VID) for DMZ port, WAN/LAN separation or inter-
VLAN switch links
• VLAN ID tag/untag options, per-port basis
• Programmable rate limiting 0Mbps to 100Mbps,
ingress and egress port, rate options for high and low
priority, per-port basis in 32Kbps increments
• Flow control or drop packet rate limiting (ingress port)
• Integrated MIB counters for fully compliant statistics
gathering, 34 MIB counters per port
• Enable/Disable option for huge frame size up to 1916
bytes per frame
• IGMP v1/v2 snooping for multicast packet filtering
• Special tagging mode to send CPU info on ingress
packet’s port value
• SPI slave (complete) and MDIO (MII PHY only) serial
management interface for control of register
configuration
• MAC-id based security lock option
• Control registers configurable on-the-fly (port-priority,
802.1p/d/q, AN...)
• CPU read access to MAC forwarding table entries
• 802.1d Spanning Tree Protocol
• Port mirroring/monitoring/sniffing: ingress and/or
egress traffic to any port or MII
• Broadcast storm protection with % control – global
and per-port basis
• Optimization for fiber-to-copper media conversion
• Full-chip hardware power-down support (register
configuration not saved)
• Per-port based software power-save on PHY (idle
link detection, register configuration preserved)
• QoS/CoS packets prioritization supports: per port,
802.1p and DiffServ based
• 802.1p/q tag insertion or removal on a per-port basis
(egress)
• MDC and MDI/O interface support to access the MII
PHY control registers (not all control registers)
• MII local loopback support
• On-chip 64Kbyte memory for frame buffering (not
shared with 1K unicast address table)
• Wire-speed reception and transmission
• Integrated look-up engine with dedicated 1K MAC
addresses
• Full duplex IEEE 802.3x and half-duplex back
pressure flow control
• Comprehensive LED support
• 7-wire SNI support for legacy MAC interface
• Automatic MDI/MDI-X crossover for plug-and-play
• Disable automatic MDI/MDI-X option
• Low power:
Core: 1.8V
Digital I/O: 3.3V
Analog I/O: 2.5V or 3.3V
• 0.18µm CMOS technology
• Commercial temperature range: 0°C to +70°C
• Industrial temperature range: –40°C to +85°C
• Available in 128-pin PQFP package
Applications
• Broadband gateway/firewall/VPN
• Integrated DSL or cable modem multi-port router
• Wireless LAN access point plus gateway
• Home networking expansion
• Standalone 10/100 switch
• Hotel/campus/MxU gateway
• Enterprise VoIP gateway/phone
• FTTx customer premise equipment
• Managed Media converter
Ordering Information
Part Number
Standard Pb-Free Temperature
Range Package
KS8995MA KSZ8995MA 0°C to +70°C 128-Pin PQFP
KS8995FQ KSZ8995FQ 0°C to +70°C 128-Pin PQFP
KS8995MAI KSZ8995MAI –40°C to +85°C 128-Pin PQFP
KS8995FQI KSZ8995FQI –40°C to +85°C 128-Pin PQFP
Micrel, Inc. KS8995MA/FQ
Semptember 2008 4 M9999-091508
Revision History
Revision Date Summary of Changes
2.0 10/10/03 Created.
2.1 10/30/03 Editorial changes on electrical characteristics.
2.2 4/01/04 Editorial changes on the TTL input and output electrical characteristics.
2.3 1/19/05 Insert recommended reset circuit, pg. 70. Editorial, Pg. 36.
2.4 4/13/05
Changed VDDIO to 3.3V.
Changed Jitter to 16 ns Max.
2.5 2/6/06 Added Pb-Free option for Industrial version.
2.6 7/12/06
Add a note for VLAN table write, improve the timing diagram for MII interface, update pin
description for PCRS, PCOL, etc. And update the description of the register bits for the
loopback, etc.
2.7 6/01/07
Add the package thermal information in the operating rating and the transformer power
consumption information in the electrical characteristics note.
2.8 03/20/08 Add KSZ8995FQ information and pin description.
2.9 09/15/08 Add KSZ8995FQ block diagram and descriptions for revision ID and LED mode.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 5 M9999-091508
Contents
System Level Applications...........................................................................................................................................8
Pin Configuration........................................................................................................................................................10
Pin Description (by Number)......................................................................................................................................11
Pin Description (by Name) .........................................................................................................................................17
Introduction .................................................................................................................................................................23
Functional Overview: Physical Layer Transceiver..................................................................................................23
100BASE-TX Transmit.............................................................................................................................................. 23
100BASE-TX Receive............................................................................................................................................... 23
PLL Clock Synthesizer.............................................................................................................................................. 23
Scrambler/De-Scrambler (100BASE-TX only).......................................................................................................... 24
100BASE-FX Operation............................................................................................................................................ 24
100BASE-FX Signal Detection ................................................................................................................................. 24
100BASE-FX far End fault ........................................................................................................................................ 24
10BASE-T Transmit .................................................................................................................................................. 24
10BASE-T Receive ................................................................................................................................................... 24
Power Management.................................................................................................................................................. 24
MDI/MDI-X Auto Crossover ...................................................................................................................................... 24
Auto-Negotiation ....................................................................................................................................................... 24
Functional Overview: Switch Core............................................................................................................................25
Address Look-Up ...................................................................................................................................................... 25
Learning .................................................................................................................................................................... 25
Migration ................................................................................................................................................................... 25
Aging......................................................................................................................................................................... 25
Forwarding ................................................................................................................................................................ 25
Switching Engine ...................................................................................................................................................... 26
Media Access Controller (MAC) Operation............................................................................................................... 26
Inter-Packet Gap (IPG)............................................................................................................................................. 26
Backoff Algorithm...................................................................................................................................................... 26
Late Collision ............................................................................................................................................................ 26
Illegal Frames ........................................................................................................................................................... 26
Flow Control.............................................................................................................................................................. 26
Half-Duplex Back Pressure...........................................................................................................................28
Broadcast Storm Protection...................................................................................................................................... 28
MII Interface Operation ............................................................................................................................................. 29
SNI Interface Operation ............................................................................................................................................ 31
Advanced Functionality..............................................................................................................................................31
Spanning Tree Support............................................................................................................................................. 31
Special Tagging Mode .............................................................................................................................................. 32
IGMP Support ........................................................................................................................................................... 33
Port Mirroring Support............................................................................................................................................... 34
VLAN Support ........................................................................................................................................................... 34
Rate Limit Support .................................................................................................................................................... 35
Configuration Interface.............................................................................................................................................. 36
I2C Master Serial Bus Configuration......................................................................................................................... 38
SPI Slave Serial Bus Configuration.......................................................................................................................... 38
MII Management Interface (MIIM) ............................................................................................................................ 41
Register Description...................................................................................................................................................42
Global Registers ....................................................................................................................................................... 43
Register 0 (0x00): Chip ID0 ...................................................................................................................................... 43
Register 1 (0x01): Chip ID1 / Start Switch................................................................................................................ 43
Register 2 (0x02): Glob al Control 0 .......................................................................................................................... 43
Register 3 (0x03): Glob al Control 1 .......................................................................................................................... 43
Register 4 (0x04): Glob al Control 2 .......................................................................................................................... 44
Register 5 (0x05): Glob al Control 3 .......................................................................................................................... 45
Micrel, Inc. KS8995MA/FQ
Semptember 2008 6 M9999-091508
Register 6 (0x07): Glob al Control 4 .......................................................................................................................... 46
Register 7 (0x07): Glob al Control 5 .......................................................................................................................... 46
Register 8 (0x08): Glob al Control 6 .......................................................................................................................... 46
Register 9 (0x09): Glob al Control 7 .......................................................................................................................... 46
Register 10 (0x0A): Global Control 8........................................................................................................................ 47
Register 11 (0x0B): Global Control 9........................................................................................................................ 47
Port Registers ........................................................................................................................................................... 48
Register 16 (0x10): Port 1 Control 0......................................................................................................................... 48
Register 17 (0x11): Port 1 Control 1......................................................................................................................... 49
Register 18 (0x12): Port 1 Control 2......................................................................................................................... 49
Register 19 (0x13): Port 1 Control 3......................................................................................................................... 50
Register 20 (0x14): Port 1 Control 4......................................................................................................................... 50
Register 21 (0x15): Port 1 Control 5......................................................................................................................... 51
Register 22 (0x16): Port 1 Control 6......................................................................................................................... 51
Register 23 (0x17): Port 1 Control 7......................................................................................................................... 51
Register 24 (0x18): Port 1 Control 8......................................................................................................................... 51
Register 25 (0x19): Port 1 Control 9......................................................................................................................... 52
Register 26 (0x1A): Port 1 Cont rol 10....................................................................................................................... 52
Register 27 (0x1B): Port 1 Cont rol 11....................................................................................................................... 52
Register 28 (0x1C): Port 1 Control 12 ...................................................................................................................... 53
Register 29 (0x1D): Port 1 Control 13 ...................................................................................................................... 54
Register 30 (0x1E): Port 1 Status 0.......................................................................................................................... 54
Register 31 (0x1F): Port 1 Control 14....................................................................................................................... 55
Advanced Control Registers ..................................................................................................................................... 55
Register 96 (0x60): TOS Priority Control Register 0 ................................................................................................ 55
Register 97 (0x61): TOS Priority Control Register 1 ................................................................................................ 55
Register 98 (0x62): TOS Priority Control Register 2 ................................................................................................ 55
Register 99 (0x63): TOS Priority Control Register 3 ................................................................................................ 55
Register 100 (0x64 ): TOS Priority Control Register 4 .............................................................................................. 55
Register 101 (0x65 ): TOS Priority Control Register 5 .............................................................................................. 56
Register 102 (0x66 ): TOS Priority Control Register 6 .............................................................................................. 56
Register 103 (0x67 ): TOS Priority Control Register 7 .............................................................................................. 56
Register 104 (0x68): MAC Address Register 0......................................................................................................... 56
Register 105 (0x69): MAC Address Register 1......................................................................................................... 56
Register 106 (0x6A): MAC Address Register 2........................................................................................................ 56
Register 107 (0x6B): MAC Address Register 3........................................................................................................ 56
Register 108 (0x6C): MAC Address Register 4........................................................................................................ 56
Register 109 (0X6D): MAC Addre ss Register 5 ....................................................................................................... 56
Register 110 (0x6E): Indirect Access Control 0........................................................................................................ 56
Register 111 (0x6F ): Indirect Access Control 1........................................................................................................ 56
Register 112 (0x70 ): Indirect Data Register 8 .......................................................................................................... 56
Register 113 (0x71 ): Indirect Data Register 7 .......................................................................................................... 57
Register 114 (0x72 ): Indirect Data Register 6 .......................................................................................................... 57
Register 115 (0x73 ): Indirect Data Register 5 .......................................................................................................... 57
Register 116 (0x74 ): Indirect Data Register 4 .......................................................................................................... 57
Register 117 (0x75 ): Indirect Data Register 3 .......................................................................................................... 57
Register 118 (0x76 ): Indirect Data Register 2 .......................................................................................................... 57
Register 119 (0x77 ): Indirect Data Register 1 .......................................................................................................... 57
Register 120 (0x78 ): Indirect Data Register 0 .......................................................................................................... 57
Register 121 (0x79 ): Digital Testing Status 0........................................................................................................... 57
Register 122 (0x7A): Digital Testing Status 1........................................................................................................... 57
Register 123 (0x7B): Digital Testing Control 0......................................................................................................... 57
Register 124 (0x7C): Digital Testing Control 1......................................................................................................... 57
Register 125 (0x7D): Analog Testing Control 0........................................................................................................ 57
Register 126 (0x7E): Analog Testing Control 1........................................................................................................ 57
Register 127 (0x7F ): Analog Testing Status............................................................................................................. 57
Micrel, Inc. KS8995MA/FQ
Semptember 2008 7 M9999-091508
Static MAC Address....................................................................................................................................................58
VLAN Address.............................................................................................................................................................60
Dynamic MAC Address...............................................................................................................................................61
MIB Counters...............................................................................................................................................................62
MIIM Registers.............................................................................................................................................................65
Register 0: MII Control .............................................................................................................................................. 65
Register 1: MII Status ............................................................................................................................................... 65
Register 2: PHYID HIGH........................................................................................................................................... 66
Register 3: PHYID LOW ........................................................................................................................................... 66
Register 4: Advertisement Ability.............................................................................................................................. 66
Register 5: Link Partner Ability ................................................................................................................................. 66
Absolute Maximum Ratings(1) ....................................................................................................................................67
Operating Ratings(2) ....................................................................................................................................................67
Electrical Characteristics(4, 5)......................................................................................................................................67
Timing Diagrams.........................................................................................................................................................69
Selection of Isolation Transformer(1).........................................................................................................................77
Package Information...................................................................................................................................................78
Micrel, Inc. KS8995MA/FQ
Semptember 2008 8 M9999-091508
System Level Applications
Ethernet
MAC
CPU
Switch Controller
On-Chip Frame Buffers
MII-SW
10/100
PHY 5
4-port
LAN
MII-P5
1-port
WAN I/F
10/100
MAC 1
10/100
MAC 2
10/100
MAC 3
10/100
MAC 4
10/100
MAC 5
10/100
PHY 1
10/100
PHY 2
10/100
PHY 3
10/100
PHY 4
SPI/GPIO
SPI
Ethernet
MAC
External WAN port PHY not required.
Figure 1. Broadband Gateway
Ethernet
MAC
CPU
Switch Controller
On-Chip Frame Buffers
MII-SW
10/100
PHY 5
4-port
LAN
MII-P5
10/100
MAC 1
10/100
MAC 2
10/100
MAC 3
10/100
MAC 4
10/100
MAC 5
10/100
PHY 1
10/100
PHY 2
10/100
PHY 3
10/100
PHY 4
WAN PHY & AFE
(xDSL, CM...) SPISPI/GPIO
Figure 2. Integrated Broadband Router
Micrel, Inc. KS8995MA/FQ
Semptember 2008 9 M9999-091508
Switch Controller
On-Chip Frame Buffers
10/100
PHY 5
5-port
LAN
10/100
MAC 1
10/100
MAC 2
10/100
MAC 3
10/100
MAC 4
10/100
MAC 5
10/100
PHY 1
10/100
PHY 2
10/100
PHY 3
10/100
PHY 4
Figure 3. Standalone Switch
Figure 4. Using KSZ8995FQ for Dual Media Converter or Fiber daisy chain connection
Micrel, Inc. KS8995MA/FQ
Semptember 2008 10 M9999-091508
Pin Configuration
128-Pin PQFP
Micrel, Inc. KS8995MA/FQ
Semptember 2008 11 M9999-091508
Pin Description (by Number)
Pin Number Pin Name Type(1) Port Pin Function(2)
1 MDI-XDIS lpd 1-5
Disable auto MDI/MDI-X.
PD (default) = normal operation.
PU = disable auto MDI/MDI-X on all ports.
2 GNDA Gnd Analog ground.
3 VDDAR P 1.8V analog VDD.
4 RXP1 I 1 Physical receive signal + (differential).
5 RXM1 I 1 Physical receive signal – (differential).
6 GNDA Gnd Analog ground.
7 TXP1 O 1 Physical transmit signal + (differential).
8 TXM1 O 1 Physical transmit signal – (differential).
9 VDDAT P 2.5V or 3.3V analog VDD.
10 RXP2 I 2 Physical receive signal + (differential).
11 RXM2 I 2 Physical receive signal – (differential).
12 GNDA Gnd Analog ground.
13 TXP2 O 2 Physical transmit signal + (differential).
14 TXM2 O 2 Physical transmit signal – (differential).
15 VDDAR P 1.8V analog VDD.
16 GNDA Gnd Analog ground.
17 ISET
Set physical transmit output current. Pull-down with a
3.01kΩ1% resistor.
18 VDDAT P 2.5V or 3.3V analog VDD.
19 RXP3 I 3 Physical receive signal + (differential).
20 RXM3 I 3 Physical receive signal - (differential).
21 GNDA Gnd Analog ground.
22 TXP3 O 3 Physical transmit signal + (differential).
23 TXM3 O 3 Physical transmit signal – (differential).
24 VDDAT P 2.5V or 3.3V analog VDD.
25 RXP4 I 4 Physical receive signal + (differential).
26 RXM4 I 4 Physical receive signal - (differential).
27 GNDA Gnd Analog ground.
28 TXP4 O 4 Physical transmit signal + (differential).
29 TXM4 O 4 Physical transmit signal – (differential).
30 GNDA Gnd Analog ground.
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
NC = No connect.
2. PU = Strap pin pull-up.
PD = Strap pull-down.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 12 M9999-091508
Pin Number Pin Name Type(1) Port Pin Function
31 VDDAR P 1.8V analog VDD.
32 RXP5 I 5 Physical receive signal + (differential).
33 RXM5 I 5 Physical receive signal – (differential).
34 GNDA Gnd Analog ground.
35 TXP5 O 5 Physical transmit signal + (differential).
36 TXM5 O 5 Physical transmit signal – (differential).
37 VDDAT P 2.5V or 3.3V analog VDD.
38 FXSD5/FXSD3 Ipd 5/3
Fiber signal detect pin. FXSD5 is for port 5 of the KS8995MA. FXSD3
is for port 3 of the KS8995FQ
39 FXSD4 Ipd 4 Fiber signal detect pin for port 4.
40 GNDA Gnd Analog ground.
41 VDDAR P 1.8V analog VDD.
42 GNDA Gnd Analog ground.
43 VDDAR P 1.8V analog VDD.
44 GNDA Gnd Analog ground.
45 MUX1 NC Factory test pins. MUX1 and MUX2 should be left unconnected for
normal operation
Mode MUX1 MUX2
46 MUX2 NC
Normal Operation NC NC
47 PWRDN_N Ipu Full-chip power down. Active low.
48 RESERVE NC Reserved pin. No connect.
49 GNDD Gnd Digital ground.
50 VDDC P 1.8V digital core VDD.
51 PMTXEN Ipd 5 PHY[5] MII transmit enable.
52 PMTXD3 Ipd 5 PHY[5] MII transmit bit 3.
53 PMTXD2 Ipd 5 PHY[5] MII transmit bit 2.
54 PMTXD1 Ipd 5 PHY[5] MII transmit bit 1.
55 PMTXD0 Ipd 5 PHY[5] MII transmit bit 0.
56 PMTXER Ipd 5 PHY[5] MII transmit error.
57 PMTXC O 5 PHY[5] MII transmit clock. PHY mode MII.
58 GNDD Gnd Digital ground.
59 VDDIO P 3.3V digital VDD for digital I/O circuitry.
60 PMRXC O 5 PHY[5] MII receive clock. PHY mode MII.
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
NC = No connect.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 13 M9999-091508
Pin Number Pin Name Type(1) Port Pin Function(2)
61 PMRXDV Ipd/O 5 PHY[5] MII receive data valid.
62 PMRXD3 Ipd/O 5
PHY[5] MII receive bit 3. Strap option: PD (default) = enable flow control;
PU = disable flow control.
63 PMRXD2 Ipd/O 5
PHY[5] MII receive bit 2. Strap option: PD (default) = disable back
pressure; PU = enable back pressure.
64 PMRXD1 Ipd/O 5
PHY[5] MII receive bit 1. Strap option: PD (default) = drop excessive
collision packets; PU = does not drop excessive collision packets.
65 PMRXD0 Ipd/O 5
PHY[5] MII receive bit 0. Strap option: PD (default) = disable aggressive
back-off algorithm in half-duplex mode; PU = enable for performance
enhancement.
66 PMRXER Ipd/O 5
PHY[5] MII receive error. Strap option: PD (default) = packet size
1518/1522 bytes; PU = 1536 bytes.
67 PCRS Ipd/O 5
PHY[5] MII carrier sense/strap option for port 4 only. PD (default) = force
half-duplex if auto-negotiation is disabled or fails. PU = force full-duplex
if auto negotiation is disabled or fails. Refer to Register 76.
68 PCOL Ipd/O 5
PHY[5] MII collision detect/ strap option for port 4 only. PD (default) = no
force flow control, normal operation. PU = force flow control. Refer to
Register 66
69 SMTXEN Ipd Switch MII transmit enable.
70 SMTXD3 Ipd Switch MII transmit bit 3.
71 SMTXD2 Ipd Switch MII transmit bit 2.
72 SMTXD1 Ipd Switch MII transmit bit 1.
73 SMTXD0 Ipd Switch MII transmit bit 0.
74 SMTXER Ipd Switch MII transmit error.
75 SMTXC I/O Switch MII transmit clock. Input in MAC mode, output in PHY mode MII.
76 GNDD Gnd Digital ground.
77 VDDIO P 3.3V digital VDD for digital I/O circuitry.
78 SMRXC I/O Switch MII receive clock. Input in MAC mode, output in PHY mode MII.
79 SMRXDV Ipd/O Switch MII receive data valid.
80 SMRXD3 Ipd/O Switch MII receive bit 3. Strap option: PD (default) = Disable Switch MII
full-duplex flow control; PU = Enable Switch MII full-duplex flow control.
81 SMRXD2 Ipd/O Switch MII receive bit 2. Strap option: PD (default) = Switch MII in full-
duplex mode; PU = Switch MII in half-duplex mode.
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
NC = No connect.
2. PU = Strap pin pull-up.
PD = Strap pull-down.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 14 M9999-091508
Pin Number Pin Name Type(1) Port Pin Function(2)
82 SMRXD1 Ipd/O Switch MII receive bit 1. Strap option: PD (default) = Switch MII in
100Mbps mode; PU = Switch MII in 10Mbps mode.
Switch MII receive bit 0; Strap option: LED mode
PD (default) = mode 0; PU = mode 1. See “Register 11.”
Mode 0, link at
100/Full LEDx[2,1,0]=0,0,0 100/Half LEDx[2,1,0]=0,1,0
10/Full LEDx[2,1,0]=0,0,1 10/Half LEDx[2,1,0]=0,1,1
Mode 1, link at
100/Full LEDx[2,1,0]=0,1,0 100/Half LEDx[2,1,0]=0,1,1
10/Full LEDx[2,1,0]=1,0,0 10/Half LEDx[2,1,0]=1,0,1
Mode 0 Mode 1
LEDX_2 Lnk/Act 100Lnk/Act
LEDX_1 Fulld/Col 10Lnk/Act
83 SMRXD0 Ipd/O
LEDX_0 Speed Full duplex
84 SCOL Ipd/O Switch MII collision detect.
85 SCRS Ipd/O Switch mode carrier sense.
86 SCONF1 Ipd
Dual MII configuration pin. For the Switch MII, KSZ8995MA supports
both MAC mode and PHY mode, KSZ8995FQ supports PHY mode
only.
Pin# (91, 86, 87): Switch MII PHY [5] MII
000 Disable, Otri Disable, Otri
001 PHY Mode MII Disable, Otri
010 MAC Mode MII Disable, Otri
011 PHY Mode SNI Disable, Otri
100 Disable Disable
101 PHY Mode MII PHY Mode MII
110 MAC Mode MII PHY Mode MII
111 PHY Mode SNI PHY Mode MII
87 SCONF0 Ipd Dual MII configuration pin.
88 GNDD Gnd Digital ground.
89 VDDC P 1.8V digital core VDD.
90 LED5-2 Ipu/O 5
LED indicator 2. Strap option: aging setup. See “Aging” section.
PU (default) = aging enable; PD = aging disable.
91 LED5-1 Ipu/O 5
LED indicator 1. Strap option: PU (default): enable PHY[5] MII I/F. PD:
tristate all PHY[5] MII output. See “Pin 86 SCONF1.”
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
NC = No connect.
2. PU = Strap pin pull-up.
PD = Strap pull-down.
Otri = Output tristated.
Fulld = Full duplex
Micrel, Inc. KS8995MA/FQ
Semptember 2008 15 M9999-091508
Pin Number Pin Name Type(1) Port Pin Function
92 LED5-0 Ipu/O 5 LED indicator 0.
93 LED4-2 Ipu/O 4 LED indicator 2.
94 LED4-1 Ipu/O 4 LED indicator 1.
95 LED4-0 Ipu/O 4 LED indicator 0.
96 LED3-2 Ipu/O 3 LED indicator 2.
97 LED3-1 Ipu/O 3 LED indicator 1.
98 LED3-0 Ipu/O 3 LED indicator 0.
99 GNDD Gnd Digital ground.
100 VDDIO P 3.3V digital VDD for digital I/O.
101 LED2-2 Ipu/O 2 LED indicator 2.
102 LED2-1 Ipu/O 2 LED indicator 1.
103 LED2-0 Ipu/O 2 LED indicator 0.
104 LED1-2 Ipu/O 1 LED indicator 2.
105 LED1-1 Ipu/O 1 LED indicator 1.
106 LED1-0 Ipu/O 1 LED indicator 0.
107 MDC Ipu All Switch or PHY[5] MII management data clock.
108 MDIO I/O All
Switch or PHY[5] MII management data I/O.
Features internal pull down to define pin state when not driven.
109 SPIQ Otri All
(1) SPI serial data output in SPI slave mode; (2) output clock at 61kHz
in I2C master mode. See “Pin 113.”
110 SPIC/SCL I/O All
(1) Input clock up to 5MHz in SPI slave mode; (2) output clock at 61kHz
in I2C master mode. See “Pin 113.”
111 SSPID/SDA I/O All
(1) Serial data input in SPI slave mode; (2) serial data input/output in
I2C master mode. See “Pin 113.”
112 SPIS_N Ipu All
Active low. (1) SPI data transfer start in SPI slave mode. When SPIS_N
is high, the KS8995MA/FQ is deselected and SPIQ is held in high
impedance state, a high-to-low transition to initiate the SPI data
transfer; (2) not used in I2C master mode.
Serial bus configuration pin.
For this case, if the EEPROM is not present, the KS8995MA/FQ will
start itself with the PS[1.0] = 00 default register values.
Pin Configuration Serial Bus Conf iguration
PS[1.0]=00 I2C Master Mode for EEPROM
PS[1.0]=01 Reserved
PS[1.0]=10 SPI Slave Mode for CPU Interface
113 PS1 Ipd
PS[1.0]=11 Factory Test Mode (BIST)
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
NC = No connect.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 16 M9999-091508
Pin Number Pin Name Type(1) Port Pin Function
114 PS0 Ipd Serial bus configuration pin. See “Pin 113.”
115 RST_N Ipu Reset the KS8995MA/FQ. Active low.
116 GNDD Gnd Digital ground.
117 VDDC P 1.8V digital core VDD.
118 TESTEN Ipd NC for normal operation. Factory test pin.
119 SCANEN Ipd NC for normal operation. Factory test pin.
120 NC NC No connect.
121 X1 I 25MHz crystal clock connection/or 3.3V tolerant oscillator input.
Oscillator should be ±100ppm.
122 X2 O 25MHz crystal clock connection.
123 VDDAP P 1.8V analog VDD for PLL.
124 GNDA Gnd Analog ground.
125 VDDAR P 1.8V analog VDD.
126 GNDA Gnd Analog ground.
127 GNDA Gnd Analog ground.
128 TEST2 NC NC for normal operation. Factory test pin.
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
NC = No connect.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 17 M9999-091508
Pin Description (by Name)
Pin Number Pin Name Type(1) Port Pin Function
39 FXSD4 I 4 Fiber signal detect/Factory test pin.
38 FXSD3/FXSD5 I 3/5 Fiber signal detect/Factory test pin for FQ or MA
124 GNDA Gnd Analog ground.
42 GNDA Gnd Analog ground.
44 GNDA Gnd Analog ground.
2 GNDA Gnd Analog ground.
16 GNDA Gnd Analog ground.
30 GNDA Gnd Analog ground.
6 GNDA Gnd Analog ground.
12 GNDA Gnd Analog ground.
21 GNDA Gnd Analog ground.
27 GNDA Gnd Analog ground.
34 GNDA Gnd Analog ground.
40 GNDA Gnd Analog ground.
120 NC NC No connect.
127 GNDA Gnd Analog ground.
126 GNDA Gnd Analog ground.
49 GNDD Gnd Digital ground.
88 GNDD Gnd Digital ground.
116 GNDD Gnd Digital ground.
58 GNDD Gnd Digital ground.
76 GNDD Gnd Digital ground.
99 GNDD Gnd Digital ground.
17 ISET
Set physical transmit output current. Pull-down with a 3.01kΩ1%
resistor.
106 LED1-0 Ipu/O 1 LED indicator 0.
105 LED1-1 Ipu/O 1 LED indicator 1.
104 LED1-2 Ipu/O 1 LED indicator 2.
103 LED2-0 Ipu/O 2 LED indicator 0.
102 LED2-1 Ipu/O 2 LED indicator 1.
101 LED2-2 Ipu/O 2 LED indicator 2.
98 LED3-0 Ipu/O 3 LED indicator 0.
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
NC = No connect.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 18 M9999-091508
Pin Number Pin Name Type(1) Port Pin Function(2)
97 LED3-1 Ipu/O 3 LED indicator 1.
96 LED3-2 Ipu/O 3 LED indicator 2.
95 LED4-0 Ipu/O 4 LED indicator 0.
94 LED4-1 Ipu/O 4 LED indicator 1.
93 LED4-2 Ipu/O 4 LED indicator 2.
92 LED5-0 Ipu/O 5 LED indicator 0.
91 LED5-1 Ipu/O 5
LED indicator 1. Strap option: PU (default) = enable PHY MII I/F PD:
tristate all PHY MII output. See “Pin 86 SCONF1.”
90 LED5-2 Ipu/O 5
LED indicator 2. Strap option: aging setup. See “Aging” section.
(default) = aging enable; PD = aging disable.
107 MDC Ipu All Switch or PHY[5] MII management data clock.
108 MDIO I/O All Switch or PHY[5] MII management data I/O.
1 MDI-XDIS Ipd 1-5 Disable auto MDI/MDI-X.
45 MUX1 NC
Factory test pins. MUX1 and MUX2 should be left unconnected for
normal operation.
46 MUX2 NC
Mode MUX1 MUX2
Normal Operation NC NC
68 PCOL Ipd/O 5
PHY[5] MII collision detect/force flow control. See “Register 18.” For
port 4 only. PD (default) = no force flow control. PU = force flow control.
67 PCRS Ipd/O 5
PHY[5] MII carrier sense/force duplex mode. See “Register 28.” For
port 4 only. PD (default) = force half-duplex if auto-negotiation is
disabled or fails. PU = force full-duplex if auto-negotiation is disabled or
fails.
60 PMRXC O 5 PHY[5] MII receive clock. PHY mode MII.
65 PMRXD0 Ipd/O 5
PHY[5] MII receive bit 0. Strap option: PD (default) = disable
aggressive back-off algorithm in half-duplex mode; PU = enable for
performance enhancement.
64 PMRXD1 Ipd/O 5
PHY[5] MII receive bit 1. Strap option: PD (default) = drop excessive
collision packets; PU = does not drop excessive collision packets.
63 PMRXD2 Ipd/O 5
PHY[5] MII receive bit 2. Strap option: PD (default) = disable back
pressure; PU = enable back pressure.
62 PMRXD3 Ipd/O 5
PHY[5] MII receive bit 3. Strap option: PD (default) = enable flow
control; PU = disable flow control.
61 PMRXDV Ipd/O 5 PHY[5] MII receive data valid.
66 PMRXER Ipd/O 5
PHY[5] MII receive error. Strap option: PD (default) = 1522/1518 bytes;
PU = packet size up to 1536 bytes.
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
NC = No connect.
2. PU = Strap pin pull-up.
PD = Strap pull-down.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 19 M9999-091508
Pin Number Pin Name Type(1) Port Pin Function
57 PMTXC O 5 PHY[5] MII transmit clock. PHY mode MII.
55 PMTXD0 Ipd 5 PHY[5] MII transmit bit 0.
54 PMTXD1 Ipd 5 PHY[5] MII transmit bit 1.
53 PMTXD2 Ipd 5 PHY[5] MII transmit bit 2.
52 PMTXD3 Ipd 5 PHY[5] MII transmit bit 3.
51 PMTXEN Ipd 5 PHY[5] MII transmit enable.
56 PMTXER Ipd 5 PHY[5] MII transmit error.
114 PS0 Ipd Serial bus configuration pin. See “Pin 113.”
113 PS1 Ipd
Serial bus configuration pin. If EEPROM is not present, the
KS8995MA/FQ will start itself with chip default (00)...
Pin Configuration Serial Bus Configuration
PS[1:0]=00 I2C Master Mode for EEPROM
PS[1:0]=01 Reserved
PS[1:0]=10 SPI Slave Mode for CPU Interface
PS[1:0]=11 Factory Test Mode (BIST)
47 PWRDN_N Ipu Full-chip power down. Active low.
48 RESERVE NC Reserved pin. No connect.
115 RST_N Ipu Reset the KS8995MA/FQ. Active low.
5 RXM1 I 1 Physical receive signal – (differential).
11 RXM2 I 2 Physical receive signal – (differential).
20 RXM3 I 3 Physical receive signal – (differential).
26 RXM4 I 4 Physical receive signal – (differential).
33 RXM5 I 5 Physical receive signal – (differential).
4 RXP1 I 1 Physical receive signal + (differential).
10 RXP2 I 2 Physical receive signal + (differential).
19 RXP3 I 3 Physical receive signal + (differential).
25 RXP4 I 4 Physical receive signal + (differential).
32 RXP5 I 5 Physical receive signal + (differential).
119 SCANEN Ipd NC for normal operation. Factory test pin.
84 SCOL Ipd/O Switch MII collision detect.
87 SCONF0 Ipd Dual MII configuration pin.
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
NC = No connect.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 20 M9999-091508
Pin Number Pin Name Type(1) Port Pin Function(2)
86 SCONF1 Ipd
Dual MII configuration pin. For the Switch MII, KSZ8995MA supports
both MAC mode and PHY mode, KSZ8995FQ supports PHY mode
only.
Pin# (91, 86, 87): Switch MII PHY [5] MII
000 Disable, Otri Disable, Otri
001 PHY Mode MII Disable, Otri
010 MAC Mode MII Disable, Otri
011 PHY Mode SNI Disable, Otri
100 Disable Disable
101 PHY Mode MII PHY Mode MII
110 MAC Mode MII PHY Mode MII
111 PHY Mode SNI PHY Mode MII
85 SCRS Ipd/O Switch mode carrier sense.
78 SMRXC I/O Switch MII receive clock. Input in MAC mode, output in PHY mode MII.
Switch MII receive bit 0; Strap option: LED mode
PD (default) = mode 0; PU = mode 1. See “Register 11.”
Mode 0 Mode 1
LEDX_2 Lnk/Act 100Lnk/Act
LEDX_1 Fulld/Col 10Lnk/Act
83 SMRXD0 Ipd/O
LEDX_0 Speed Full duplex
82 SMRXD1 Ipd/O Switch MII receive bit 1. Strap option: PD (default) = Switch MII in
100Mbps mode; PU = Switch MII in 10Mbps mode.
81 SMRXD2 Ipd/O Switch MII receive bit 2. Strap option: PD (default) = Switch MII in full-
duplex mode; PU = Switch MII in half-duplex mode.
80 SMRXD3 Ipd/O Switch MII receive bit 3. Strap option: PD (default) = Disable Switch MII
full-duplex flow control; PU = Enable Switch MII full-duplex flow control.
79 SMRXDV Ipd/O Switch MII receive data valid.
75 SMTXC I/O Switch MII transmit clock. Input in MAC mode, output in PHY mode MII.
73 SMTXD0 Ipd Switch MII transmit bit 0.
72 SMTXD1 Ipd Switch MII transmit bit 1.
71 SMTXD2 Ipd Switch MII transmit bit 2.
70 SMTXD3 Ipd Switch MII transmit bit 3.
69 SMTXEN Ipd Switch MII transmit enable.
74 SMTXER Ipd Switch MII transmit error.
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
Otri = Output tristated.
NC = No connect.
2. PU = Strap pin pull-up.
PD = Strap pull-down.
Fulld = Full duplex
Micrel, Inc. KS8995MA/FQ
Semptember 2008 21 M9999-091508
Pin Number Pin Name Type(1) Port Pin Function
110 SPIC/SCL I/O All
(1) Input clock up to 5MHz in SPI slave mode; (2) output clock at 61kHz
in I2C master mode. See “Pin 113.”
111 SSPID/SDA I/O All
(1) Serial data input in SPI slave mode; (2) serial data input/output in
I2C master mode. See “Pin 113.”
109 SPIQ Otri All
(1) SPI serial data output in SPI slave mode; (2) output clock at 61kHz
in I2C master mode. See “Pin 113.”
112 SPIS_N Ipu All
Active low. (1) SPI data transfer start in SPI slave mode. When SPIS_N
is high, the KS8995MA/FQ is deselected and SPIQ is held in high
impedance state, a high-to-low transition to initiate the SPI data
transfer; (2) not used in I2C master mode.
128 TEST2 NC NC for normal operation. Factory test pin.
118 TESTEN Ipd NC for normal operation. Factory test pin.
8 TXM1 O 1 Physical transmit signal – (differential).
14 TXM2 O 2 Physical transmit signal – (differential).
23 TXM3 O 3 Physical transmit signal – (differential).
29 TXM4 O 4 Physical transmit signal – (differential).
36 TXM5 O 5 Physical transmit signal – (differential).
7 TXP1 O 1 Physical transmit signal + (differential).
13 TXP2 O 2 Physical transmit signal + (differential).
22 TXP3 O 3 Physical transmit signal + (differential).
28 TXP4 O 4 Physical transmit signal + (differential).
35 TXP5 O 5 Physical transmit signal + (differential).
123 VDDAP P 1.8V analog VDD for PLL.
41 VDDAR P 1.8V analog VDD.
43 VDDAR P 1.8V analog VDD.
3 VDDAR P 1.8V analog VDD.
15 VDDAR P 1.8V analog VDD.
31 VDDAR P 1.8V analog VDD.
125 VDDAR P 1.8V analog VDD.
18 VDDAT P 2.5V or 3.3V analog VDD.
9 VDDAT P 2.5V or 3.3V analog VDD.
24 VDDAT P 2.5V or 3.3V analog VDD.
37 VDDAT P 2.5V or 3.3V analog VDD.
50 VDDC P 1.8V digital core VDD.
Notes:
1. P = Power supply.
I = Input.
O = Output.
I/O = Bidirectional.
Gnd = Ground.
Ipu = Input w/internal pull-up.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Ipu/O = Input w/internal pull-up during reset, output pin otherwise.
Otri = Output tristated.
NC = No connect.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 22 M9999-091508
Pin Number Pin Name Type(1) Port Pin Function
89 VDDC P 1.8V digital core VDD.
117 VDDC P 1.8V digital core VDD.
59 VDDIO P 3.3V digital VDD for digital I/O circuitry.
77 VDDIO P 3.3V digital VDD for digital I/O circuitry.
100 VDDIO P 3.3V digital VDD for digital I/O circuitry.
121 X1 I
25MHz crystal clock connection/or 3.3V tolerant oscillator input.
Oscillator should be ±100ppm.
122 X2 O 25MHz crystal clock connection.
Notes:
1. P = Power supply.
I = Input.
O = Output.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 23 M9999-091508
Introduction
The KS8995MA/FQ contains five 10/100 physical layer transceivers and five media access control (MAC) units with
an integrated Layer 2 managed switch. The device runs in three modes. The first mode is as a five-port integrated
switch. The second is as a five-port switch with the fifth port decoupled from the physical port. In this mode, access to
the fifth MAC is provided through a media independent interface (MII). This is useful for implementing an integrated
broadband router. The third mode uses the dual MII feature to recover the use of the fifth PHY. This allows the
additional broadband gateway configuration, where the fifth PHY may be accessed through the MII-P5 port.
The KS8995MA/FQ has the flexibility to reside in a managed or unmanaged design. In a managed design, a host
processor has complete control of the KS8995MA/FQ via the SPI bus, or partial control via the MDC/MDIO interface.
An unmanaged design is achieved through I/O strapping or EEPROM programming at system reset time.
On the media side, the KS8995MA/FQ supports IEEE 802.3 10BASE-T, 100BASE-TX on all ports, and the
KS8995MA supports 100BASE-FX on ports 4 and 5, and the KS8995FQ supports 100BASE-FX on ports 3 and 4.
The KS8995MA/FQ can be used as fully managed 5-port standalone switch or two separate media converters.
Physical signal transmission and reception are enhanced through the use of patented analog circuitry that makes the
design more efficient and allows for lower power consumption and smaller chip die size.
The major enhancements from the KS8995E to the KS8995MA/FQ are support for host processor management, a
dual MII interface, tag as well as port based VLAN, spanning tree protocol support, IGMP snooping support, port
mirroring support and rate limiting functionality.
Functional Overview: Physical Layer Transceiver
100BASE-TX Transmit
The 100BASE-TX transmit function performs parallel-to-serial conversion, 4B/5B coding, scrambling, NRZ-to-NRZI
conversion, MLT3 encoding and transmission. The circuit starts with a parallel-to-serial conversion, which converts
the MII data from the MAC into a 125MHz serial bit stream. The data and control stream is then converted into 4B/5B
coding followed by a scrambler. The serialized data is further converted from NRZ-to-NRZI format, and then
transmitted in MLT3 current output. The output current is set by an external 1% 3.01kΩ resistor for the 1:1
transformer ratio. It has a typical rise/fall time of 4ns and complies with the ANSI TP-PMD standard regarding
amplitude balance, overshoot, and timing jitter. The wave-shaped 10BASE-T output is also incorporated into the
100BASE-TX transmitter.
100BASE-TX Receive
The 100BASE-TX receiver function performs adaptive equalization, DC restoration, MLT3-to-NRZI conversion, data
and clock recovery, NRZI-to-NRZ conversion, de-scrambling, 4B/5B decoding, and serial-to-parallel conversion. The
receiving side starts with the equalization filter to compensate for inter-symbol interference (ISI) over the twisted pair
cable. Since the amplitude loss and phase distortion is a function of the length of the cable, the equalizer has to
adjust its characteristics to optimize the performance. In this design, the variable equalizer will make an initial
estimation based on comparisons of incoming signal strength against some known cable characteristics, then tunes
itself for optimization. This is an ongoing process and can self-adjust against environmental changes such as
temperature variations.
The equalized signal then goes through a DC restoration and data conversion block. The DC restoration circuit is
used to compensate for the effect of baseline wander and improve the dynamic range. The differential data
conversion circuit converts the MLT3 format back to NRZI. The slicing threshold is also adaptive.
The clock recovery circuit extracts the 125MHz clock from the edges of the NRZI signal. This recovered clock is then
used to convert the NRZI signal into the NRZ format. The signal is then sent through the de-scrambler followed by
the 4B/5B decoder. Finally, the NRZ serial data is converted to the MII format and provided as the input data to the
MAC.
PLL Clock Synthesizer
The KS8995MA/FQ generates 125MHz, 42MHz, 25MHz, and 10MHz clocks for system timing. Internal clocks are
generated from an external 25MHz crystal or oscillator.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 24 M9999-091508
Scrambler/De-Scrambler (100BASE-TX only)
The purpose of the scrambler is to spread the power spectrum of the signal in order to reduce EMI and baseline
wander. The data is scrambled through the use of an 11-bit wide linear feedback shift register (LFSR). This can
generate a 2047-bit non-repetitive sequence. The receiver will then de-scramble the incoming data stream with the
same sequence at the transmitter.
100BASE-FX Operation
100BASE-FX operation is very similar to 100BASE-TX operation except that the scrambler/de-scrambler and MLT3
encoder/decoder are bypassed on transmission and reception. In this mode the auto-negotiation feature is bypassed
since there is no standard that supports fiber auto-negotiation.
100BASE-FX Signal Detection
The physical port runs in 100BASE-FX mode if FXSDx >0.6V for ports 3, 4 (KSZ8995FQ) or ports 4, 5 (KSZ8995MA)
only. This signal is internally referenced to 1.25V. The fiber module interface should be set by a voltage divider such
that FXSDx ‘H’ is above this 1.25V reference, indicating signal detect, and FXSDx ‘L’ is below the 1.25V reference to
indicate no signal. When FXSDx is below 0.6V then 100BASE-FX mode is disabled. Since there is no auto-
negotiation for 100BASE-FX mode, the ports must be forced to either full or half-duplex for the fiber ports. Note that
strap-in options exist to set duplex mode for port 4, but not for port 3, 5.
100BASE-FX far End fault
far end fault occurs when the signal detection is logically false from the receive fiber module. When this occurs, the
transmission side signals the other end of the link by sending 84 1s followed by a zero in the idle period between
frames. The far end fault may be disabled through register settings.
10BASE-T Transmit
The output 10BASE-T driver is incorporated into the 100BASE-T driver to allow transmission with the same
magnetics. They are internally wave-shaped and pre-emphasized into outputs with a typical 2.3V amplitude. The
harmonic contents are at least 27dB below the fundamental when driven by an all-ones Manchester-encoded signal.
10BASE-T Receive
On the receive side, input buffer and level detecting squelch circuits are employed. A differential input receiver circuit
and a PLL perform the decoding function. The Manchester-encoded data stream is separated into clock signal and
NRZ data. A squelch circuit rejects signals with levels less than 400mV or with short pulsewidths in order to prevent
noises at the RXP or RXM input from falsely triggering the decoder. When the input exceeds the squelch limit, the
PLL locks onto the incoming signal and the KS8995MA/FQ decodes a data frame. The receiver clock is maintained
active during idle periods in between data reception.
Power Management
The KS8995MA/FQ features a per port power down mode. To save power the user can power down ports that are
not in use by setting port control registers or MII control registers. In addition, it also supports full chip power down
mode. When activated, the entire chip will be shutdown.
MDI/MDI-X Auto Crossover
The KS8995MA/FQ supports MDI/MDI-X auto crossover. This facilitates the use of either a straight connection CAT-
5 cable or a crossover CAT-5 cable. The auto-sense function will detect remote transmit and receive pairs, and
correctly assign the transmit and receive pairs from the Micrel device. This can be highly useful when end users are
unaware of cable types and can also save on an additional uplink configuration connection. The auto crossover
feature may be disabled through the port control registers.
Auto-Negotiation
The KS8995MA/FQ conforms to the auto-negotiation protocol as described by the 802.3 committee. Auto-negotiation
allows unshielded twisted pair (UTP) link partners to select the best common mode of operation. In auto-negotiation
the link partners advertise capabilities across the link to each other. If auto-negotiation is not supported or the link
partner to the KS8995MA/FQ is forced to bypass auto-negotiation, then the mode is set by observing the signal at
the receiver. This is known as parallel mode because while the transmitter is sending auto-negotiation
Micrel, Inc. KS8995MA/FQ
Semptember 2008 25 M9999-091508
advertisements, the receiver is listening for advertisements or a fixed signal protocol.
The flow for the link setup is shown in Figure 5.
Start
Auto Negotiation
Force Link Setting
Listen for 10BASE-T
Link Pulses
Listen for
100BASE-TX Idles
Attempt
Auto-Negotiation
Link Mode Set
Bypass
Auto-Negotiation
and Set Link Mode
Link Mode Set ?
Parallel
Operation
Join Flow
No
Yes
Yes
No
Figure 5. Auto-Negotiation
Functional Overview: Switch Core
Address Look-Up
The internal look-up table stores MAC addresses and their associated information. It contains a 1K unicast address
table plus switching information. The KS8995MA/FQ is guaranteed to learn 1K addresses and distinguishes itself
from a hash-based look-up table, which depending on the operating environment and probabilities, may not
guarantee the absolute number of addresses it can learn.
Learning
The internal look-up engine updates its table with a new entry if the following conditions are met:
• The received packet’s source address (SA) does not exist in the look-up table.
• The received packet is good; the packet has no receiving errors and is of legal length.
The look-up engine inserts the qualified SA into the table, along with the port number and time stamp. If the table is
full, the last entry of the table is deleted first to make room for the new entry.
Migration
The internal look-up engine also monitors whether a station is moved. If this occurs, it updates the table accordingly.
Migration happens when the following conditions are met:
• The received packet’s SA is in the table but the associated source port information is different.
• The received packet is good; the packet has no receiving errors and is of legal length.
The look-up engine will update the existing record in the table with the new source port information.
Aging
The look-up engine will update the time stamp information of a record whenever the corresponding SA appears. The
time stamp is used in the aging process. If a record is not updated for a period of time, the look-up engine will
remove the record from the table. The look-up engine constantly performs the aging process and will continuously
remove aging records. The aging period is 300 + 75 seconds. This feature can be enabled or disabled through
Register 3 or by external pull-up or pull-down resistors on LED[5][2]. See “Register 3” section.
Forwarding
The KS8995MA/FQ will forward packets using an algorithm that is depicted in the following flowcharts. Figure 6
shows stage one of the forwarding algorithm where the search engine looks up the VLAN ID, static table, and
Micrel, Inc. KS8995MA/FQ
Semptember 2008 26 M9999-091508
dynamic table for the destination address, and comes up with “port to forward 1” (PTF1). PTF1 is then further
modified by the spanning tree, IGMP snooping, port mirroring, and port VLAN processes to come up with “port to
forward 2” (PTF2), as shown in Figure 7. This is where the packet will be sent.
KS8995MA/FQ will not forward the following packets:
• Error packets. These include framing errors, FCS errors, alignment errors, and illegal size packet errors.
• 802.3x pause frames. The KS8995MA/FQ will intercept these packets and perform the appropriate actions.
• “Local” packets. Based on destination address (DA) look-up. If the destination port from the look-up table matches
the port where the packet was from, the packet is defined as “local.”
Switching Engine
The KS8995MA/FQ features a high-performance switching engine to move data to and from the MAC’s, packet
buffers. It operates in store and forward mode, while the efficient switching mechanism reduces overall latency. The
KS8995MA/FQ has a 64kB internal frame buffer. This resource is shared between all five ports. The buffer sharing
mode can be programmed through Register 2. See “Register 2.” In one mode, ports are allowed to use any free
buffers in the buffer pool. In the second mode, each port is only allowed to use 1/5 of the total buffer pool. There are
a total of 512 buffers available. Each buffer is sized at 128B.
Media Access Controller (MAC) Opera tion
The KS8995MA/FQ strictly abides by IEEE 802.3 standards to maximize compatibility.
Inter-Packet Gap (IPG)
If a frame is successfully transmitted, the 96-bit time IPG is measured between the two consecutive MTXEN. If the
current packet is experiencing collision, the 96-bit time IPG is measured from MCRS and the next MTXEN.
Backoff Algorithm
The KS8995MA/FQ implements the IEEE Std. 802.3 binary exponential back-off algorithm, and optional “aggressive
mode” back off. After 16 collisions, the packet will be optionally dropped depending on the chip configuration in
Register 3. See “Register 3.”
Late Collision
If a transmit packet experiences collisions after 512-bit times of the transmission, the packet will be dropped.
Illegal Frames
The KS8995MA/FQ discards frames less than 64 bytes and can be programmed to accept frames up to 1536 bytes
in Register 4. For special applications, the KS8995MA/FQ can also be programmed to accept frames up to 1916
bytes in Register 4. Since the KS8995MA/FQ supports VLAN tags, the maximum sizing is adjusted when these tags
are present.
Flow Control
The KS8995MA/FQ supports standard 802.3x flow control frames on both transmit and receive sides.
On the receive side, if the KS8995MA/FQ receives a pause control frame, the KS8995MA/FQ will not transmit the
next normal frame until the timer, specified in the pause control frame, expires. If another pause frame is received
before the current timer expires, the timer will be updated with the new value in the second pause frame. During this
period (being flow controlled), only flow control packets from the KS8995MA/FQ will be transmitted.
On the transmit side, the KS8995MA/FQ has intelligent and efficient ways to determine when to invoke flow control.
The flow control is based on availability of the system resources, including available buffers, available transmit
queues and available receive queues.
The KS8995MA/FQ flow controls a port that has just received a packet if the destination port resource is busy. The
KS8995MA/FQ issues a flow control frame (XOFF), containing the maximum pause time defined in IEEE standard
802.3x. Once the resource is freed up, the KS8995MA/FQ sends out the other flow control frame (XON) with zero
pause time to turn off the flow control (turn on transmission to the port). A hysteresis feature is also provided to
prevent over-activation and deactivation of the flow control mechanism.
The KS8995MA/FQ flow controls all ports if the receive queue becomes full.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 27 M9999-091508
Start
VLAN ID
VALID?
PTF1=NULL
Search Static
Table
Search complete.
Get PTF1 from
static table.
Dynamic
Table
Search
Search complete.
Get PTF1 from
VLAN table.
Search complete.
Get PTF1 from
dynamic table.
PTF1
-Search VLAN table.
-Ingress VLAN filtering
-Discard NPVID check
YES
NO
FOUND
NOT
FOUND
FOUND
NOT
FOUND
Search based on
DA or DA+FID
This search is based on
DA+FID
Figure 6. DA Look-Up Flowchart – Stage 1
Spanning Tree
Process
PTF1
IGM P Proces s
Port Mirror
Process
Port VLAN
Membership
Check
PTF2
-Check receiving port's receive enable bit
-Check destination port's transmit enable bit
-Check whether packets are special (BPDU
or specified)
-Applied to MAC #1 to #4
-MAC#5 is reserved for microprocessor
-IGM P will be forwarded to port 5
-RX Mirror
-TX Mirror
-RX or TX Mirror
-RX and TX Mirror
Figure 7. DA Resolution Flow chart – Stage 2
Micrel, Inc. KS8995MA/FQ
Semptember 2008 28 M9999-091508
Half-Duplex Back Pressure
The KS8995MA/FQ also provides a half-duplex back pressure option (note: this is not in IEEE 802.3 standards). The
activation and deactivation conditions are the same as the ones given for full-duplex mode. If back pressure is
required, the KS8995MA/FQ sends preambles to defer the other station's transmission (carrier sense deference). To
avoid jabber and excessive deference as defined in IEEE 802.3 standard, after a certain period of time, the
KS8995MA/FQ discontinues carrier sense but raises it quickly after it drops packets to inhibit other transmissions.
This short silent time (no carrier sense) is to prevent other stations from sending out packets and keeps other
stations in a carrier sense deferred state. If the port has packets to send during a back pressure situation, the carrier-
sense-type back pressure is interrupted and those packets are transmitted instead. If there areno more packets to
send, carrier-sense-type back pressure becomes active again until switch resources are free. If a collisionoccurs, the
binary exponential backoff algorithm is skipped and carrier sense is generated immediately, reducing the chanceof
further colliding and maintaining carrier sense to prevent reception of packets.To ensure no packet loss in 10BASE-T
or 100BASE-TX half-duplex modes, the user must enable the following:
• Aggressive backoff (Register 3, bit 0)
• No excessive collision drop (Register 4, bit 3)
• Back pressure (Register 4, bit 5)
These bits are not set as the default because this is not the IEEE standard.
Broadcast Storm Protection
The KS8995MA/FQ has an intelligent option to protect the switch system from receiving too many broadcast packets.
Broadcastpackets are normally forwarded to all ports except the source port and thus use too many switch resources
(bandwidth andavailable space in transmit queues). The KS8995MA/FQ has the option to include “multicast packets”
for storm control. Thebroadcast storm rate parameters are programmed globally and can be enabled or disabled on a
per port basis. The rate is basedon a 50ms interval for 100BT and a 500ms interval for 10BT. At the beginning of
each interval, the counter is cleared to zeroand the rate limit mechanism starts to count the number of bytes during
the interval. The rate definition is described in Registers6 and 7. The default setting for Registers 6 and 7 is 0x4A (74
decimal). This is equal to a rate of 1%, calculated as follows:
148,800 frames/sec ¥ 50ms/interval ¥ 1% = 74 frames/interval (approx.) = 0x4A
Micrel, Inc. KS8995MA/FQ
Semptember 2008 29 M9999-091508
MII Interface Operation
The media independent interface (MII) is specified by the IEEE 802.3 committee and provides a common interface
betweenphysical layer and MAC layer devices. The KS8995MA/FQ provides two such interfaces. The MII-P5
interface is used to connectto the fifth PHY, whereas the MII-SW interface is used to connect to the fifth MAC. Each
of these MII interfaces contains twodistinct groups of signals, one for transmission and the other for receiving. Table
1 describes the signals used in the MII-P5 interface.
SNI Signal Description KS8995MA/FQ Signal
MTXEN Transmit enable PMTXEN
MTXER Transmit error PMTXER
MTXD3 Transmit data bit 3 PMTXD[3]
MTXD2 Transmit data bit 2 PMTXD[2]
MTXD1 Transmit data bit 1 PMTXD[1]
MTXD0 Transmit data bit 0 PMTXD[0]
MTXC Transmit clock PMTXC
MCOL Collision detection PCOL
MCRS Carrier sense PCRS
MRXDV Receive data valid PMRXDV
MRXER Receive error PMRXER
MRXD3 Receive data bit 3 PMRXD[3]
MRXD2 Receive data bit 2 PMRXD[2]
MRXD1 Receive data bit 1 PMRXD[1]
MRXD0 Receive data bit 0 PMRXD[0]
MRXC Receive clock PMRXC
MDC Management data clock MDC
MDIO Management data I/O MDIO
Table 1. MII – P5 Signals (PHY Mode)
Micrel, Inc. KS8995MA/FQ
Semptember 2008 30 M9999-091508
The table 2 shows three connection ways,
1. The first and second columns show the connections for external MAC and MII-SW PHY mode.
2. The fourth and fifth columns show the connections for external PHY and MII-SW MAC mode.
3. The second and fifth columns show the back to back connections for two MII-SWs of two devices.
PHY Mode Connection MAC Mode Connection
External MAC KS8995MA/FQ
Signal Description External PHY KS8995M A Only
Signal
MTXEN SMTXEN Transmit enable MTXEN SMRXDV
MTXER SMTXER Transmit error MTXER Not used
MTXD3 SMTXD[3] Transmit data bit 3 MTXD3 SMRXD[3]
MTXD2 SMTXD[2] Transmit data bit 2 MTXD2 SMRXD[2]
MTXD1 SMTXD[1] Transmit data bit 1 MTXD1 SMRXD[1]
MTXD0 SMTXD[0] Transmit data bit 0 MTXD0 SMRXD[0]
MTXC SMTXC Transmit clock MTXC SMRXC
MCOL SCOL Collision detection MCOL SCOL
MCRS SCRS Carrier sense MCRS SCRS
MRXDV SMRXDV Receive data valid MRXDV SMTXEN
MRXER Not used Receive error MRXER SMTXER
MRXD3 SMRXD[3] Receive data bit 3 MRXD3 SMTXD[3]
MRXD2 SMRXD[2] Receive data bit 2 MRXD2 SMTXD[2]
MRXD1 SMRXD[1] Receive data bit 1 MRXD1 SMTXD[1]
MRXD0 SMRXD[0] Receive data bit 0 MRXD0 SMTXD[0]
MRXC SMRXC Receive clock MRXC SMTXC
Table 2. MII – SW Signals
The MII-P5 interface operates in PHY mode only, while the MII-SW interface operates in either MAC mode or PHY
mode for KSZ8995MA. The MII-SW interface operates in PHY mode only for KSZ8995FQ. These interfaces are
nibble-wide data interfaces and therefore run at 1/4 the network bit rate (not encoded). Additional signals on the
transmit side indicate when data is valid or when an error occurs during transmission. Likewise, the receive side has
indicators that convey when the data is valid and without physical layer errors. For half-duplex operation there is a
signal that indicates a collision has occurred during transmission.
Note that the signal MRXER is not provided on the MII-SW interface for PHY mode operation and the signal MTXER
is not provided on the MII-SW interface for MAC mode operation. Normally MRXER would indicate a receive error
coming from the physical layer device. MTXER would indicate a transmit error from the MAC device. These signals
are not appropriate for this configuration. For PHY mode operation, if the device interfacing with the KS8995MA/FQ
has an MRXER pin, it should be tied low. For MAC mode operation, if the device interfacing with the KS8995MA has
an MTXER pin, it should be tied low.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 31 M9999-091508
SNI Interface Operation
The serial network interface (SNI) is compatible with some controllers used for network layer protocol processing.
This interface can be directly connected to these types of devices. The signals are divided into two groups, one for
transmission and the other for reception. The signals involved are described in Table 3.
SNI Signal Description KS8995MA/FQ
Signal
TXEN Transmit Enable SMTXEN
TXD Serial Transmit Data SMTXD[0]
TXC Transmit Clock SMTXC
COL Collision Detection SCOL
CRS Carrier Sense SMRXDV
RXD Serial Receive Data SMRXD[0]
RXC Receive Clock SMRXC
Table 3. SNI Signals
This interface is a bit-wide data interface and therefore runs at the network bit rate (not encoded). An additional
signal on the transmit side indicates when data is valid. Likewise, the receive side has an indicator that conveys
when the data is valid.
For half-duplex operation there is a signal that indicates a collision has occurred during transmission.
Advanced Functionality
Spanning Tree Support
Port 5 is the designated port for spanning tree support.
The other ports (port 1 – port 4) can be configured in one of the five spanning tree states via “transmit enable,”
“receive enable,” and “learning disable” register settings in Registers 18, 34, 50, and 66 for ports 1, 2, 3, and 4,
respectively. The following description shows the port setting and software actions taken for each of the five
spanning tree states.
Disable state: the port should not forward or receive any packets. Learning is di sabled.
Port setting: "transmit enable = 0, receive enable = 0, learning disable = 1."
Software action: the processor should not send any packets to the port. The switch may still send specific packets to
the processor (packets that match some entries in the static table with “overriding bit” set) and the processor should
discard those packets. Note: processor is connected to port 5 via MII interface. Address learning is disabled on the
port in this state.
Blocking state: only packets to the processor are forwarded. Learning is disabled.
Port setting: "transmit enable = 0, receive enable = 0, learning disable = 1"
Software action: the processor should not send any packets to the port(s) in this state. The processor should
program the “Static MAC table” with the entries that it needs to receive (e.g., BPDU packets). The “overriding” bit
should also be set so that the switch will forward those specific packets to the processor. Address learning is
disabled on the port in this state.
Listening state: only packe t s to and from the processor are forwarded. Learning i s disable d.
Port setting: "transmit enable = 0, receive enable = 0, learning disable = 1.
"Software action: The processor should program the static MAC table with the entries that it needs to receive (e.g.
BPDU packets). The “overriding” bit should be set so that the switch will forward those specific packets to the
processor. The processor may send packets to the port(s) in this state, see “Special Tagging Mode” section for
details. Address learning is disabled on the port in this state.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 32 M9999-091508
Learning state: only packets to and from the pro cesso r are forwarded. Learning is enabled.
Port setting: “transmit enable = 0, receive enable = 0, learning disable = 0.”
Software action: The processor should program the static MAC table with the entries that it needs to receive (e.g.,
BPDU packets). The “overriding” bit should be set so that the switch will forward those specific packets to the
processor. The processor may send packets to the port(s) in this state, see “Special Tagging Mode” section for
details. Address learning is enabled on the port in this state.
Forwarding state: packets are forwarded and received normally. Learning is enabled.
Port setting: “transmit enable = 1, receive enable = 1, learning disable = 0.”
Software action: The processor should program the static MAC table with the entries that it needs to receive (e.g.,
BPDU packets). The “overriding” bit should be set so that the switch will forward those specific packets to the
processor. The processor may send packets to the port(s) in this state, see “Special Tagging Mode” section for
details. Address learning is enabled on the port in this state.
Special Tagging Mode
The special tagging mode is designed for spanning tree protocol IGMP snooping and is flexible for use in other
applications. The special tagging mode, similar to 802.1q, requires software to change network drivers to
insert/modify/strip/interpret the special tag. This mode is enabled by setting both Register 11 bit 0 and Register 80 bit
2.
802.1q Tag Format Special Tag Format
TPID (tag protocol identifier, 0x8100) + TCI STPID (special tag identifier, 0x8100) + TCI 0x810 + 4 bit for “port mask”) + TCI
Table 4. Special Tagging Mode Format
The STPID will only be seen and used on the port 5 interface, which should be connected to a processor. Packets
from the processor to the switch should be tagged with STPID and the port mask defined as below:
“0001” packet to port 1 only
“0010” packet to port 2 only“0100” packet to port 3 only
“1000” packet to port 4 only
“0011” packet broadcast to port 1 and port 2
......
“1111” packet broadcast to port 1, 2, 3 and 4.
“0000” normal tag, will use the KS8995MA/FQ internal look-up result. Normal packets should use this setting. If
packets from the processors do not have a tag, the KS8995MA/FQ will treat them as normal packets and an internal
look-up will be performed.The KS8995MA/FQ uses a non-zero “port mask” to bypass the look-up result and override
any port setting, regardless of port states (blocking, disable, listening, learning). Table 5 shows the egress rules
when dealing with STPID.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 33 M9999-091508
Ingress Tag Field
Tx Port
“Tag Insertion”
Tx Port
“Tag Removal”
Egress Action to Tag Field
(0x810+ port mask) 0 0 •
•
•
•
Modify tag field to 0x8100.
Recalculate CRC.
No change to TCI if not null VID.
Replace VID with ingress (port 5) port VID if null VID.
(0x810+ port mask) 0 1 •
•
•
(STPID + TCI) will be removed.
Padding to 64 bytes if necessary.
Recalculate CRC.
(0x810+ port mask) 1 0 •
•
•
•
Modify tag field to 0x8100.
Recalculate CRC.
No change to TCI if not null VID.
Replace VID with ingress (port 5) port VID if null VID.
(0x810+ port mask) 1 1 •
•
•
•
Modify tag field to 0x8100.
Recalculate CRC.
No change to TCI if not null VID.
Replace VID with ingress (port 5) port VID if null VID.
Not tagged Don’t care Don’t care Determined by the dynamic MAC address table.
Table 5. STPID Egress Rules (Processor to Switch Po rt 5)
For packets from regular ports (port 1 - port 4) to port 5, the port mask is used to tell the processor which port the
packet was received on, defined as:
“0001” from port 1,
“0010” from port 2,
“0100” from port 3,
“1000” from port 4
No values other than the previous four defined should be received in this direction in the special mode. Table 6
shows the egress rule for this direction.
Ingress Packets Eg ress Action to Tag Field
Tagged with 0x8100 + TCI • Modify TPID to 0x810 + “port mask,” which indicates source port.
• No change to TCI, if VID is not null.
• Replace null VID with ingress port VID.
• Recalculate CRC.
Not tagged • Insert TPID to 0x810 + “port mask,” which indicates source port.
• Insert TCI with ingress port VID.
• Recalculate CRC.
Table 6. STPID Egress Rule s (Switch to Processor)
IGMP Support
There are two parts involved to support IGMP in Layer 2. The first part is “IGMP” snooping. The switch will trap IGMP
packets and forward them only to the processor port. The IGMP packets are identified as IP packets (either Ethernet
IP packets or IEEE 802.3 SNAP IP packets) AND IP version = 0x4 AND protocol number = 0x2. The second part is
“multicast address insertion” in the static MAC table. Once the multicast address is programmed in the static MAC
table, the multicast session will be trimmed to the subscribed ports, instead of broadcasting to all ports. To enable
this feature, set Register 5 bit 6 to 1. Also “special tag mode” needs to be enabled, so that the processor knows
which port the IGMP packet was received on. Enable “special tag mode” by setting both Register 11 bit 0 and
Register 80 bit 2.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 34 M9999-091508
Port Mirroring Support
KS8995MA/FQ supports “port mirror” comprehensively as:
1. “Receive Only” mirror on a port. All the packets received on the port will be mirrored on the sniffer port. For
example, port 1 is programmed to be “rx sniff,” and port 5 is programmed to be the “sniffer port.” A packet,
received on port 1, is destined to port 4 after the internal look-up. The KS8995MA/FQ will forward the packet to
both port 4 and port 5. KS8995MA/FQ can optionally forward even “bad” received packets to port 5.
2. “Transmit Only” mirror on a port. All the packets transmitted on the port will be mirrored on the sniffer port. For
example, port 1 is programmed to be “tx sniff,” and port 5 is programmed to be the “sniffer port.” A packet,
received on any of the ports, is destined to port 1 after the internal look-up. The KS8995MA/FQ will forward the
packet to both ports 1 and 5.
3. “Receive and Transmit” mirror on two ports. All the packets received on port A AND transmitted on port B will
be mirrored on the sniffer port. To turn on the “AND” feature, set Register 5 bit 0 to 1. For example, port 1 is
programmed to be “rx sniff,” port 2 is programmed to be “transmit sniff,” and port 5 is programmed to be the
“sniffer port.” A packet, received on port 1, is destined to port 4 after the internal look-up. The KS8995MA/FQ
will forward the packet to port 4 only, since it does not meet the “AND” condition. A packet, received on port 1,
is destined to port 2 after the internal look-up. The KS8995MA/FQ will forward the packet to both port 2 and
port 5.
Multiple ports can be selected to be “rx sniffed” or “tx sniffed.” And any port can be selected to be the “sniffer port.”
All these per port features can be selected through Register 17.
VLAN Support
KS8995MA/FQ supports 16 active VLANs out of 4096 possible VLANs specified in IEEE 802.1q. KS8995MA/FQ
provides a 16-entry VLAN table, which converts VID (12 bits) to FID (4 bits) for address look-up. If a non-tagged or
null-VID-tagged packet is received, the ingress port VID is used for look-up. In the VLAN mode, the look-up process
starts with VLAN table look-up to determine whether the VID is valid. If the VID is not valid, the packet will be
dropped and its address will not be learned. If the VID is valid, FID is retrieved for further look-up. FID+DA is used to
determine the destination port. FID+SA is used for learning purposes.
DA found in
Static MAC table
USE FID
Flag?
FID Match? DA+FID found in
Dynamic MAC table
Action
No Don’t care Don’t care No Broadcast to the membership ports defined in
the VLAN table bit [20:16].
No Don’t care Don’t care Yes Send to the destination port defined in the
dynamic MAC table bit [54:52].
Yes 0 Don’t care Don’t care Send to the destination port(s) defined in the
static MAC table bit [52:48].
Yes 1 No No Broadcast to the membership ports defined in
the VLAN table bit [20:16].
Yes 1 No Yes Send to the destination port defined in the
dynamic MAC table bit [54:52].
Yes 1 Yes Don’t care Send to the destination port(s) defined in the
static MAC table bit [52:48].
Table 7. FID+DA Look-Up in the VLAN Mode
Micrel, Inc. KS8995MA/FQ
Semptember 2008 35 M9999-091508
SA+FID found in
Dynamic MAC table
Action
No The SA+FID will be learned into the dynamic table.
Yes Time stamp will be updated.
Table 8. FID+SA Look-Up in the VLAN Mode
Advanced VLAN features are also supported in KS8995MA/FQ, such as “VLAN ingress filtering” and “discard non
PVID” defined in Register 18 bit 6 and bit 5. These features can be controlled on a port basis.
Rate Limit Support
KS8995MA/FQ supports hardware rate limiting on “receive” and “transmit” independently on a per port basis. It also
supports rate limiting in a priority or non-priority environment. The rate limit starts from 0Kbps and goes up to the line
rate in steps of 32Kbps. The KS8995MA/FQ uses one second as an interval. At the beginning of each interval, the
counter is cleared to zero, and the rate limit mechanism starts to count the number of bytes during this interval.
For receive, if the number of bytes exceeds the programmed limit, the switch will stop receiving packets on the port
until the “one second” interval expires. There is an option provided for flow control to prevent packet loss. If the rate
limit is programmed greater than or equal to 128Kbps and the byte counter is 8K bytes below the limit, the flow
control will be triggered. If the rate limit is programmed lower than 128Kbps and the byte counter is 2K bytes below
the limit, the flow control will be triggered.
For transmit, if the number of bytes exceeds the programmed limit, the switch will stop transmitting packets on the
port until the “one second” interval expires.
If priority is enabled, the KS8995MA/FQ can support different rate controls for both high priority and low priority
packets. This can be programmed through Registers 21–27.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 36 M9999-091508
Configuration Interface
The KS8995MA/FQ can function as a managed switch or unmanaged switch. If no EEPROM or micro-controller
exists, the KS8995MA/FQ will operate from its default setting. Some default settings are configured via strap in
options as indicated in the table below.
Pin # Pin Name PU/PD(1) Description(1)
1 MDI-XDIS Ipd Disable auto MDI/MDI-X.
PD = (default) = normal operation
PU = disable auto MDI/MDI-X on all ports.
45 MUX1 NC Factory test pins. MUX1 and MUX2 should be left unconnected for normal
operation.
Mode MUX1 MUX2
46 MUX2 NC
Normal Operation NC NC
62 PMRXD3 Ipd/O PHY[5] MII receive bit 3. Strap option: PD (default) = enable flow control; PU =
disable flow control.
63 PMRXD2 Ipd/O PHY[5] MII receive bit 2. Strap option: PD (default) = disable back pressure; PU
= enable back pressure.
64 PMRXD1 Ipd/O PHY[5] MII receive bit 1. Strap option: PD (default) = drop excessive collision
packets; PU = does not drop excessive collision packets.
65 PMRXD0 Ipd/O PHY[5] MII receive bit 0. Strap option: PD (default) = disable aggressive back-
off algorithm in half-duplex mode; PU = enable for performance enhancement.
66 PMRXER Ipd/O PHY[5] MII receive error. Strap option: PD (default) = 1522/1518 bytes; PU =
packet size up to 1536 bytes.
67 PCRS Ipd/O PHY[5] MII carrier sense/strap option for port 4 only. PD (default) = force half-
duplex if auto-negotiation is disabled or fails. PU = force full-duplex if auto-
negotiation is disabled or fails. Refer to register 76.
68 PCOL Ipd/O PHY[5] MII collision detect/strap option for port 4 only. PD (default) = no force
flow control. PU = force flow control. Refer to register 66.
80 SMRXD3 Ipd/O Switch MII receive bit 3. Strap option: PD (default) = disable switch MII full-
duplex flow control; PU = enable switch MII full-duplex flow control.
81 SMRXD2 Ipd/O Switch MII receive bit 2. Strap option: PD (default) = switch MII in full-duplex
mode; PU = switch MII in half-duplex mode.
82 SMRXD1 Ipd/O Switch MII receive bit 1. Strap option: PD (default) = switch MII in 100Mbps
mode; PU = switch MII in 10Mbps mode.
Switch MII receive bit 0. Strap option: LED mode PD (default) = mode 0; PU =
mode 1. See “Register 11.”
Mode 0 Mode 1
LEDX_2 Lnk/Act 100Lnk/Act
LEDX_1 Fulld/Col 10Lnk/Act
83 SMRXD0 Ipd/O
LEDX_0 Speed Fulld
Notes:
1. NC = No connect.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Fulld = Full duplex.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 37 M9999-091508
Pin # Pin Name PU/PD(1) Description(1)
Dual MII configuration pin. For the Switch MII, KSZ8995MA supports both MAC
mode and PHY mode, KSZ8995FQ supports PHY mode only.
Pins 91, 86, 87 Switch MII PHY [5] MII
000 Disable, Otri Disable, Otri
001 PHY Mode MII Disable, Otri
010 MAC Mode MII Disable, Otri
011 PHY Mode SNI Disable, Otri
100 Disable Disable
101 PHY Mode MII PHY Mode MII
110 MAC Mode MII PHY Mode MII
86 SCONF1 Ipd
111 PHY Mode SNI PHY Mode MII
87 SCONF0 Ipd Dual MII configuration pin.
90 LED5-2 Ipu/O LED indicator 2. Strap option: Aging setup. See “Aging” section PU (default) =
aging enable; PD = aging disable.
91 LED5-1 Ipu/O LED indicator 1. Strap option: PU (default): enable PHY[5] MII I/F. PD: tristate
all PHY[5] MII output. See “Pin 86 SCONF1.”
Serial bus configuration pin. For this case, if the EEPROM is not present, the
KS8995MA/FQ will start itself with the PS[1:0] =00 default register values .
Pin Configuration Serial Bus Configuration
PS[1:0]=00 I2C Master Mode for EEPROM
PS[1:0]=01 Reserved
PS[1:0]=10 SPI Slave Mode for CPU Interface
113 PS1 Ipd
PS[1:0]=11 Factory Test Mode (BIST)
114 PS0 Ipd Serial bus configuration pin. See “Pin 113.”
128 TEST2 NC NC for normal operation. Factory test pin.
Notes:
1. NC = No connect.
Ipd = Input w/internal pull-down.
Ipd/O = Input w/internal pull-down during reset, output pin otherwise.
Otri = Output tristated.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 38 M9999-091508
I2C Master Serial Bus Configuration
If a 2-wire EEPROM exists, the KS8995MA/FQ can perform more advanced features like broadcast storm protection
and rate control. The EEPROM should have the entire valid configuration data from Register 0 to Register 109
defined in the “Memory Map,” except the status registers. After reset, the KS8995MA/FQ will start to read all 110
registers sequentially from the EEPROM. The configuration access time (tprgm) is less than 15ms as shown in Figure
8.
....
....
....
RST_N
SCL
SD
A
tprgm <15 ms
Figure 8. KS8995MA/FQ EEPROM
Configuration Timing Diagram
To configure the KS8995MA/FQ with a pre-configured EEPROM use the following steps:
1. At the board level, connect pin 110 on the KS8995MA/FQ to the SCL pin on the EEPROM. Connect pin 111 on
the KS8995MA/FQ to the SDA pin on the EEPROM.
2. Set the input signals PS[1:0] (pins 113 and 114, respectively) to “00.” This puts the KS8995MA/FQ serial bus
configuration into I2C master mode.
3. Be sure the board-level reset signal is connected to the KS8995MA/FQ reset signal on pin 115 (RST_N).
4. Program the contents of the EEPROM before placing it on the board with the desired configuration data. Note
that the first byte in the EEPROM must be “95” for the loading to occur properly. If this value is not correct, all
other data will be ignored.
5. Place EEPROM on the board and power up the board. Assert the active-low board level reset to RST_N on the
KS8995MA/FQ. After the reset is de-asserted, the KS8995MA/FQ will begin reading configuration data from the
EEPROM. The configuration access time (tprgm) is less than 15ms.
Note: For proper operation, make sure that pin 47 (PWRDN_N) is not asserted during the reset operation.
SPI Slave Serial Bus Configuration
The KS8995MA/FQ can also act as an SPI slave device. Through the SPI, the entire feature set can be enabled,
including “VLAN,” “IGMP snooping,” “MIB counters,” etc. The external master device can access any register from
Register 0 to Register 127 randomly. The system should configure all the desired settings before enabling the switch
in the KS8995MA/FQ. To enable the switch, write a "1" to Register 1 bit 0.
Two standard SPI commands are supported (00000011 for “READ DATA,” and 00000010 for “WRITE DATA”). To
speed configuration time, the KS8995MA/FQ also supports multiple reads or writes. After a byte is written to or read
from the KS8995MA/FQ, the internal address counter automatically increments if the SPI Slave Select Signal
(SPIS_N) continues to be driven low. If SPIS_N is kept low after the first byte is read, the next byte at the next
address will be shifted out on SPIQ. If SPIS_N is kept low after the first byte is written, bits on the Master Out Slave
Input (SPID) line will be written to the next address. Asserting SPIS_N high terminates a read or write operation. This
means that the SPIS_N signal must be asserted high and then low again before issuing another command and
address. The address counter wraps back to zero once it reaches the highest address. Therefore the entire register
set can be written to or read from by issuing a single command and address.
The KS8995MA/FQ is able to support a 5MHz SPI bus. A high performance SPI master is recommended to prevent
internal counter overflow.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 39 M9999-091508
To use the KS8995MA/FQ SPI:
1. At the board level, connect KS8995MA/FQ pins as follows:
KS8995MA/FQ Pin
Number
KS8995MA/FQ Signal
Name
Microprocessor Signal Description
112 SPIS_N SPI Slave Select
110 SPIC SPI Clock
111 SPID Master Out Slave Input
109 SPIQ Master In Slave Output
Table 9. SPI Connections
2. Set the input signals PS[1:0] (pins 113 and 114, respectively) to “10” to set the serial configuration to SPI slave
mode.
3. Power up the board and assert a reset signal. After reset wait 100µs, the start switch bit in Register 1 will be set
to ‘0’. Configure the desired settings in the KS8995MA/FQ before setting the start register to ‘1.'
4. Write configuration to registers using a typical SPI write data cycle as shown in Figure 9 or SPI multiple write as
shown in Figure 11. Note that data input on SPID is registered on the rising edge of SPIC.
5. Registers can be read and configuration can be verified with a typical SPI read data cycle as shown in Figure 10
or a multiple read as shown in Figure 12. Note that read data is registered out of SPIQ on the falling edge of
SPIC.
6. After configuration is written and verified, write a ‘1’ to Register 1 bit 0 to begin KS8995MA/FQ operation.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 40 M9999-091508
SPIQ
SPIC
SPID
SPIS_N
00000010X A7 A6 A5 A4 A3 A2 A1 A0
WRITE COMMAND WRITE ADDRESS WRITE DATA
D2 D0D1D3D4D5D6D7
Figure 9. SPI Write Data Cycle
SPIQ
SPIC
SPID
SPIS_N
00000011X A7 A6 A5 A4 A3 A2 A1 A0
D7 D6 D5 D4 D3 D2 D1 D0
READ COMMAND READ ADDRESS READ DATA
Figure 10. SPI Read Data Cycle
Micrel, Inc. KS8995MA/FQ
Semptember 2008 41 M9999-091508
SPIQ
SPIC
SPID
SPIS_N
00000010X A7 A6 A5 A4 A3 A2 A1 A0
WRITE COMMAND WRITE ADDRESS Byte 1
D2 D0D1D3D4D5D6D7
SPIQ
SPIC
SPID
SPIS_N
D7 D6 D5 D4 D4 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
Byte 2 Byte 3 ... Byte N
D2 D0D1D3D4D5D6D7
Figure 11. SPI Multiple Write
SPIQ
SPIC
SPID
SPIS_N
00000011X A7 A6 A5 A4 A3 A2 A1 A0
D7 D6 D5 D4 D3 D2 D1 D0
READ COMMAND READ ADDRESS Byte 1
XXXXXXXXXXXXXXXX
Byte 2 Byte 3 ... Byte N
XXXXXXXX
XXXXXXXX
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
SPIQ
SPIC
SPID
SPIS_N
Figure 12. SPI Multiple Read
MII Management Interface (MIIM)
A standard MIIM interface is provided for all five PHY devices in the KS8995MA/FQ. An external device with
MDC/MDIO capability is able to read PHY status or to configure PHY settings. The device is able to meet IEEE
specification of 2.5MHz MDC clock. For details on the MIIM interface standard please reference the IEEE 802.3
specification (section 22.2.4.5). The MIIM interface does not have access to all the configuration registers in the
KS8995MA/FQ. It can only access the standard MII registers. See “MIIM Registers.” The SPI interface, on the other
hand, can be used to access the entire KS8995MA/FQ feature set.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 42 M9999-091508
Register Description
Offset
Decimal Hex Description
0-1 0x00-0x01 Chip ID Registers
2-11 0x02-0x0B Global Control Registers
12-15 0x0C-0x0F Reserved
16-29 0x10-0x1D Port 1 Control Registers
30-31 0x1E-0x2F Port 1 Status Registers
32-45 0x20-0x2D Port 2 Control Registers
46-47 0x2E-0x2F Port 2 Status Registers
48-61 0x30-0x3D Port 3 Control Registers
62-63 0x3E-0x3F Port 3 Status Registers
64-77 0x40-0x4D Port 4 Control Registers
78-79 0x4E-0x4F Port 4 Status Registers
80-93 0x50-0x5D Port 5 Control Registers
94-95 0x5E-0x5F Port 5 Status Registers
96-103 0x60-0x67 TOS Priority Control Registers
104-109 0x68-0x6D MAC Address Registers
110-111 0x6E-0x6F Indirect Access Control Registers
112-120 0x70-0x78 Indirect Data Registers
121-122 0x79-0x7A Digital Testing Status Registers
123-124 0x7B-0x7C Digital Testing Control Registers
125-126 0x7D-0x7E Analog Testing Control Registers
127 0x7F Analog Testing Status Register
Micrel, Inc. KS8995MA/FQ
Semptember 2008 43 M9999-091508
Global Registers
Address Name Description Mode Default
Register 0 (0x00): Chip ID0
7-0 family ID Chip family. RO 0x95
Register 1 (0x01): Chip ID1 / Start Switch
7-4 Chip ID 0x0 is assigned to M series. (95MA) RO 0x0
3-1 Revision ID Revision ID RO Based on real chip
revision. 0x02=B2,
0x03=B3,
0x04=B4,
0x05=B5, etc.
0 Start Switch 1, start the chip when external pins (PS1, PS0) = (1,0) or
(0,1). Note: in (PS1,PS0) = (0,0) mode, the chip will
start automatically, after trying to read the external
EEPROM. If EEPROM does not exist, the chip will use
default values for all internal registers. If EEPROM is
present, the contents in the EEPROM will be checked.
The switch will check: (1) Register 0 = 0x95,
(2) Register 1 [7:4] = 0x0. If this check is OK, the
contents in the EEPROM will override chip register
default values =0, chip will not start when external pins
(PS1, PS0) = (1,0) or (0,1).
Note: (PS1, PS0) = (1,1) for Factory test only.
RW
0x0
Register 2 (0x02): Global Control 0
7 Reserved Reserved. R/W 0x0
6-4 802.1p Base Priority Used to classify priority for incoming 802.1q packets
“User priority” is compared against this value ⊕ :
classified as high priority. < : classified as low priority.
R/W 0x4
3 Enable PHY MII 1, enable PHY MII-P5 interface.
Note: if not enabled, the switch will tri-state all outputs.
R/W Pin LED5-1 strap
option.
Pull-down (0):
isolate. Pull-up
(1): Enable.
Note: LED[5][1]
has internal pull-
up.
2 Buffer Share Mode 1, buffer pool is shared by all ports. A port can use more
buffer when other ports are not busy.
0, a port is only allowed to use 1/5 of the buffer pool.
R/W 0x1
1 UNH Mode 1, the switch will drop packets with 0x8808 in T/L filed, or
DA=01-80-C2-00-00-01.
0, the switch will drop packets qualified as “flow control”
packets.
R/W 0
0 Link Change Age 1, link change from “link” to “no link” will cause fast aging
(<800µs) to age address table faster. After an age cycle
is complete, the age logic will return to normal (300 + 75
seconds ). Note: If any port is
unplugged, all addresses will be automatically aged out.
R/W 0
Register 3 (0x03): Global Control 1
7 Pass All Frames 1, switch all packets including bad ones. Used solely for
debugging purpose. Works in conjunction with
sniffer mode.
R/W 0
6 Reserved Reserved. R/W 0
Micrel, Inc. KS8995MA/FQ
Semptember 2008 44 M9999-091508
Address Name Description Mode Default
5 IEEE 802.3x Transmit
Flow Control Disable
0, will enable transmit flow control based on AN result.
1, will not enable transmit flow control regardless of
AN result.
R/W Pin PMRXD3
strap option.
Pull-down(0):
Enable Tx flow
control. Pull-up(1):
Disable Tx/Rx flow
control.
Note: PMRX D3
has internal pull-
down.
4 IEEE 802.3x Receive
Flow Control Disable
0, will enable receive flow control based on AN result.
1, will not enable receive flow control regardless of
AN result.
Note: Bit 5 and bit 4 default values are controlled by
the same pin, but they can be programmed
independently.
R/W Pin PMRXD3
strap
option. Pull-down
(0): Enable Rx
flow
control. Pull-up
(1):
Disable Tx/Rx flow
control.
Note: PMRX D3
has internal pull-
down.
3 Frame Length Field Check 1, will check frame length field in the IEEE packets
If the actual length does not match, the packet will be
dropped (for L/T <1500) .
R/W 0
2 Aging Enable 1, Enable age function in the chip.
0, Disable aging function.
R/W Pin LED[5][2]
strap option. Pull-
down (0): Aging
disable Pull-up
(1): Aging enable.
Note: LED[5][2]
has internal pull
up.
1 fast age Enable 1 = Turn on fast age (800µs). R/W 0
0 Aggressive Back Off Enable 1 = Enable more aggressive back-off algorithm in half
duplex mode to enhance performance. This is not an
IEEE standard.
R/W Pin PMRXD0
strap option. Pull-
down (0): Disable
aggressive back
off. Pull-up (1):
Aggressive back
off. Note:
PMRXD0 has
internal pull down.
Register 4 (0x04): Global Control 2
7 Unicast Port-VLAN
Mismatch Discard
This feature is used for port VLAN (described in Register
17, Register 33...). 1, all packets can not cross VLAN
boundary. 0, unicast packets (excluding unknown/
multicast/broadcast) can cross VLAN boundary.
R/W 1
6 Multicast Storm Protection
Disable
1, “Broadcast Storm Protection” does not include
multicast packets. Only DA=FFFFFFFFFFFF packets will
be regulated.
0, “Broadcast Storm Protection” includes DA =
FFFFFFFFFFFF and DA[40] = 1 packets.
R/W 1
5 Back Pressure Mode 1, carrier sense based backpressure is selected.
0, collision based backpressure is selected.
R/W 1
Micrel, Inc. KS8995MA/FQ
Semptember 2008 45 M9999-091508
Address Name Description Mode Default
4 Flow Control and Back
Pressure fair Mode
1, fair mode is selected. In this mode, if a flow control port
and a non-flow control port talk to the same destination
port, packets from the non-flow control port may be
dropped. This is to prevent the flow control port from
being flow controlled for an extended period of time.
0, in this mode, if a flow control port and a non-flow
control port talk to the same destination port, the flow
control port will be flow controlled. This may not be “fair”
to the flow control port.
R/W 1
3 No Excessive Collision Drop 1, the switch will not drop packets when 16 or more
collisions occur.
0, the switch will drop packets when 16 or more collisions
occur.
R/W Pin PMRXD1
strap option. Pull-
down (0): Drop
excessive collision
packets. Pull-up
(1):
Don’t drop
excessive collision
packets. Note:
PMRXD1 has
internal pull down.
2 Huge Packet Support 1, will accept packet sizes up to 1916 bytes (inclusive).
This bit setting will override setting from bit 1 of the same
register. 0, the max packet size will be determined by bit 1
of this register.
R/W 0
1 Legal Maximum Packet
Size Check Disable
1, will accept packet sizes up to 1536 bytes (inclusive).
0, 1522 bytes for tagged packets (not including packets
with STPID from CPU to ports 1-4), 1518 bytes for
untagged packets. Any packets larger than the specified
value will be dropped.
R/W Pin PMRXER
strap option.
Pull-down (0):
1518/1522 byte
packets. Pull-up
(1): 1536 byte
packets.
Note: PMRXER
has internal pull-
down.
0 Priority Buffer Reserve 1, each output queue is pre-allocated 48 buffers, used
exclusively for high priority packets. It is recommended to
enable this when priority queue feature is turned on.
0, no reserved buffers for high priority packets.
R/W 0
Register 5 (0x05): Global Control 3
7 802.1q VLAN Enable 1, 802.1q VLAN mode is turned on. VLAN table needs to
set up before the operation.
0, 802.1q VLAN is disabled.
R/W 0
6 IGMP Snoop Enable on
Switch MII Interface
1, IGMP snoop enabled. All the IGMP packets will be
forwarded to Switch MII port.
0, IGMP snoop disabled.
R/W 0
5 Enable Direct Mode on
Switch MII Interface
1, direct mode on port 5. This is a special mode for the
Switch MII interface. Using preamble before MRXDV to
direct switch to forward packets, bypassing internal look-
up.
0, normal operation.
R/W 0
4 Enable Pre-Tag on
Switch MII Interface
1, packets forwarded to Switch MII interface will be
pre-tagged with the source port number (preamble
before MRXDV).
0, normal operation.
R/W 0
3-2 Priority Scheme Select 00 = always deliver high priority packets first.
01 = deliver high/low packets at ratio 10/1.
10 = deliver high/low packets at ratio 5/1.
11 = deliver high/low packets at ratio 2/1.
R/W 00
Micrel, Inc. KS8995MA/FQ
Semptember 2008 46 M9999-091508
Address Name Description Mode Default
1 Enable “Tag” Mask 1, the last 5 digits in the VID field are used as a mask to
determine which port(s) the packet should be forwarded
to.
0, no tag masks.
R/W 0
0 Sniff Mode Select 1, will do Rx AND Tx sniff (both source port and
destination port need to match).
0, will do Rx OR Tx sniff (Either source port or destination
port needs to match).
This is the mode used to implement Rx only sniff.
R/W 0
Register 6 (0x07): Global Control 4
7 Switch MII Back
Pressure Enable
1, enable half-duplex back pressure on switch MII
interface.
0, disable back pressure on switch MII interface.
R/W 0
6 Switch MII Half-Duplex
Mode
1, enable MII interface half-duplex mode.
0, enable MII interface full-duplex mode.
R/W Pin SMRXD2
strap option. Pull-
down (0): Full-
duplex mode. Pull-
up (1): Half-duplex
mode. Note:
SMRXD2 has
internal pull-down.
5 Switch MII Flow
Control Enable
1, enable full-duplex flow control on switch MII interface.
0, disable full-duplex flow control on switch MII interface.
R/W Pin SMRXD3
strap
option. Pull-down
(0): disable flow
control. Pull-up(1):
enable flow
control.
Note: SMRXD3
has internal pull-
down.
4 Switch MII 10BT 1, the switch interface is in 10Mbps mode.
0, the switch interface is in 100Mbps mode.
R/W Pin SMRXD1
strap option. Pull-
down (0): Enable
100Mbps. Pull-up
(1): Enable
10Mpbs.
Note: SMRX D1
has internal pull-
down.
3 Null VID Replacement 1, will replace null VID with port VID (12 bits).
0, no replacement for null VID.
R/W 0
2-0 Broadcast Storm
Protection Rate Bit [10:8]
This along with the next register determines how many
“64 byte blocks” of packet data allowed on an input port in
a preset period. The period is 50ms for 100BT or 500ms
for 10BT. The default is 1%.
R/W 000
Register 7 (0x07): Global Control 5
7-0 Broadcast Storm
Protection Rate Bit [7:0]
This along with the previous register determines how many
“64 byte blocks” of packet data are allowed on an input
port in a preset period. The period is 50ms for
100BT or 500ms for 10BT. The default is 1%.
R/W 0x4A(1)
Register 8 (0x08): Global Control 6
7-0 Factory Testing Reserved R/W 0x24
Register 9 (0x09): Global Control 7
7-0 Factory Testing Reserved R/W 0x28
Note:
1. 148,800 frames/sec × 50ms/interval × 1% = 74 frames/interval (approx.) = 0x4A.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 47 M9999-091508
Address Name Description Mode Default
Register 10 (0x0A): Global Control 8
7-0 Factory Testing Reserved R/W 0x24
Register 11 (0x0B): Global Control 9
7-4 Reserved N/A 0
3 PHY Power
Save
1 = disable PHY power save mode.
0 = enable PHY power save mode.
R/W 0
2 Factory Setting Reserved R/W 0
0 = led mode 0.
1 = led mode 1.
Mode 0, link at
100/Full LEDx[2,1,0]=0,0,0 100/Half LEDx[2,1,0]=0,1,0
10/Full LEDx[2,1,0]=0,0,1 10/Half LEDx[2,1,0]=0,1,1
Mode 1, link at
100/Full LEDx[2,1,0]=0,1,0 100/Half LEDx[2,1,0]=0,1,1
10/Full LEDx[2,1,0]=1,0,0 10/Half LEDx[2,1,0]=1,0,1
(0=LED on, 1=LED off)
R/W Pin SMRXD- strap
option. Pull-
down(0): Enabled
led mode 0. Pull-
up(1): Enabled led
mode 1.
Note: SMPXD0
has internal pull-
down 0.
Mode 0 Mode 1
LEDX_2 Lnk/Act 100Lnk/Act
LEDX_1 Fulld/Col 10Lnk/Act
1 LED Mode
LEDX_0 Speed Fulld
0 Special TIPD Mode 1 = enable special tag mode.
0 = disable special tag mode.
R/W 0
Micrel, Inc. KS8995MA/FQ
Semptember 2008 48 M9999-091508
Port Registers
The following registers are used to enable features that are assigned on a per port basis. The register bit
assignments are the same for all ports, but the address for each port is different, as indicated.
Register 16 (0x10): Port 1 Control 0
Register 32 (0x20): Port 2 Control 0
Register 48 (0x30): Port 3 Control 0
Register 64 (0x40): Port 4 Control 0
Register 80 (0x50): Port 5 Control 0
Address Name Description Mode Default
7 Broadcast Storm
Protection Enable
1, enable broadcast storm protection for ingress
packets on the port.
0, disable broadcast storm protection.
R/W 0
6 DiffServ Priority
Classification Enable
1, enable DiffServ priority classification for ingress
packets on port.
0, disable DiffServ function.
R/W 0
5 802.1p Priority
Classification Enable
1, enable 802.1p priority classification for ingress
packets on port.
0, disable 802.1p.
R/W 0
4 Port-Based Priority
Classification Enable
1, ingress packets on the port will be classified as high
priority if “DiffServ” or “802.1p” classification is not
enabled or fails to classify.
0, ingress packets on port will be classified as low
priority if “DiffServ” or “802.1p” classification is not
enabled or fails to classify.
Note: “DiffServ”, “802.1p” and port priority can be
enabled at the same time. The OR’ed result of 802.1p
and DSCP overwrites the port priority.
R/W 0
3 Reserved Reserved R/W 0
2 Tag insertion 1, when packets are output on the port, the switch will
add 802.1q tags to packets without 802.1q tags when
received. The switch will not add tags to packets
already tagged. The tag inserted is the ingress port’s
“port VID.”
0, disable tag insertion.
R/W 0
1 Tag Removal 1, when packets are output on the port, the switch will
remove 802.1q tags from packets with 802.1q tags
when received. The switch will not modify packets
received without tags.
0, disable tag removal.
R/W 0
0 Priority Enable 1, the port output queue is split into high and low
priority queues.
0, single output queue on the port. There is no priority
differentiation even though packets are classified into
high or low priority.
R/W 0
Micrel, Inc. KS8995MA/FQ
Semptember 2008 49 M9999-091508
Register 17 (0x11): Port 1 Control 1
Register 33 (0x21): Port 2 Control 1
Register 49 (0x31): Port 3 Control 1
Register 65 (0x41): Port 4 Control 1
Register 81 (0x51): Port 5 Control 1
Address Name Description Mode Default
7 Sniffer Port 1, port is designated as sniffer port and will transmit
packets that are monitored.
0, port is a normal port.
R/W 0
6 Receive Sniff 1, all the packets received on the port will be marked
as “monitored packets” and forwarded to the
designated “sniffer port.”
0, no receive monitoring.
R/W 0
5 Transmit Sniff 1, all the packets transmitted on the port will be marked
as “monitored packets” and forwarded to the
designated “sniffer port.”
0, no transmit monitoring.
R/W 0
4-0 Port VLAN Membership Define the port’s Port VLAN membership. Bit 4 stands
for port 5, bit 3 for port 4...bit 0 for port 1. The port can
only communicate within the membership. A ‘1’
includes a port in the membership, a ‘0’ excludes a port
from membership.
R/W 0x1f
Register 18 (0x12): Port 1 Control 2
Register 34 (0x22): Port 2 Control 2
Register 50 (0x32): Port 3 Control 2
Register 66 (0x42): Port 4 Control 2
Register 82 (0x52): Port 5 Control 2
Address Name Description Mode Default
7 Reserved Reserved 0x0
6 Ingress VLAN Filtering. 1, the switch will discard packates whose VID port
membership in VLAN table bit[20:16] does not include
the ingress port.
0, no ingress VLAN filtering.
R/W 0
5 Discard Non-PVID
packets
1, the switch will discard packets whose VID does not
match ingress port default VID.
0, no packets will be discarded.
R/W 0
4 Force Flow Control 1, will always enable Rx and Tx flow control on the
port, regardless of AN result.
0, the flow control is enabled based on AN result.
R/W 0
For port 4 only,
there is a special
configuration pin
to set the default,
Pin PCOL strap
option. Pull-down
(0): No force flow
control. Pull-up
(1): Force flow
control. Note:
PCOL has
internal pull-down.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 50 M9999-091508
Address Name Description Mode Default
3 Back Pressure Enable 1, enable port half-duplex back pressure.
0, disable port half-duplex back pressure.
R/W Pin PMRXD2
strap option. Pull-
down (0): disable
back pressure.
Pull-up(1): enable
back pressure.
Note: PMRXD2
has internal pull-
down.
2 Transmit Enable 1, enable packet transmission on the port.
0, disable packet transmission on the port.
R/W 1
1 Receive Enable 1, enable packet reception on the port.
0, disable packet reception on the port.
R/W 1
0 Learning Disable 1, disable switch address learning capability.
0, enable switch address learning.
R/W 0
Note:
Bits 2-0 are used for spanning tree support. See “Spanning Tree Support” section.
Register 19 (0x13): Port 1 Control 3
Register 35 (0x23): Port 2 Control 3
Register 51 (0x33): Port 3 Control 3
Register 67 (0x43): Port 4 Control 3
Register 83 (0x53): Port 5 Control 3
Address Name Description Mode Default
7-0 Default Tag [15:8] Port’s default tag, containing:
7-5: user priority bits
4: CFI bit
3-0 : VID[11:8]
R/W 0
Register 20 (0x14): Port 1 Control 4
Register 36 (0x24): Port 2 Control 4
Register 52 (0x34): Port 3 Control 4
Register 68 (0x44): Port 4 Control 4
Register 84 (0x54): Port 5 Control 4
Address Name Description Mode Default
7-0 Default Tag [7:0] Default port 1’s tag, containing:
7-0: VID[7:0]
R/W 1
Note:
Registers 19 and 20 (and those corresponding to other ports) serve two purposes: (1) Associated with the ingress untagged packets, and used for
egress tagging; (2) Default VID for the ingress untagged or null-VID-tagged packets, and used for address look up.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 51 M9999-091508
Register 21 (0x15): Port 1 Control 5
Register 37 (0x25): Port 2 Control 5
Register 53 (0x35): Port 3 Control 5
Register 69 (0x45): Port 4 Control 5
Register 85 (0x55): Port 5 Control 5
Address Name Description Mode Default
7-0 Transmit High Priority
Rate Control [7:0]
This along with port control 7, bits [3:0] form a 12-bit
field to determine how many “32Kbps” high priority
blocks can be transmitted (in a unit of 4K bytes in a
one second period).
R/W 0
Register 22 (0x16): Port 1 Control 6
Register 38 (0x26): Port 2 Control 6
Register 54 (0x36): Port 3 Control 6
Register 70 (0x46): Port 4 Control 6
Register 86 (0x56): Port 5 Control 6
Address Name Description Mode Default
7-0 Transmit Low Priority
Rate Control [7:0]
This along with port control 7, bits [7:4] form a 12-bit
field to determine how many “32Kbps” low priority
blocks can be transmitted (in a unit of 4K bytes in a
one second period).
R/W 0
Register 23 (0x17): Port 1 Control 7
Register 39 (0x27): Port 2 Control 7
Register 55 (0x37): Port 3 Control 7
Register 71 (0x47): Port 4 Control 7
Register 87 (0x57): Port 5 Control 7
Address Name Description Mode Default
7-4 Transmit Low Priority
Rate Control [11:8]
This along with port control 6, bits [7:0] form a 12-bit
field to determine how many “32Kbps” low priority
blocks can be transmitted (in a unit of 4K bytes in a
one second period).
R/W 0
3-0 Transmit High Priority
Rate Control [11:8]
This along with port control 5, bits [7:0] form a 12-bit
field to determine how many “32Kbps” high priority
blocks can be transmitted (in unit of 4K bytes in a one
second period).
R/W 0
Register 24 (0x18): Port 1 Control 8
Register 40 (0x28): Port 2 Control 8
Register 56 (0x38): Port 3 Control 8
Register 72 (0x48): Port 4 Control 8
Register 88 (0x58): Port 5 Control 8
Address Name Description Mode Default
7-0 Receive High Priority
Rate Control [7:0]
This along with port control 10, bits [3:0] form a 12-bit
field to determine how many “32Kbps” high priority
blocks can be received (in a unit of 4K bytes in a one
second period).
R/W 0
Micrel, Inc. KS8995MA/FQ
Semptember 2008 52 M9999-091508
Register 25 (0x19): Port 1 Control 9
Register 41 (0x29): Port 2 Control 9
Register 57 (0x39): Port 3 Control 9
Register 73 (0x49): Port 4 Control 9
Register 89 (0x59): Port 5 Control 9
Address Name Description Mode Default
7-0 Receive Low Priority
Rate Control [7:0]
This along with port control 10, bits [7:4] form a 12-bit
field to determine how many “32Kbps” low priority
blocks can be received (in a unit of 4K bytes in a one
second period).
R/W 0
Register 26 (0x1A): Port 1 Control 10
Register 42 (0x2A): Port 2 Cont rol 10
Register 58 (0x3A): Port 3 Cont rol 10
Register 74 (0x4A): Port 4 Cont rol 10
Register 90 (0x5A): Port 5 Cont rol 10
Address Name Description Mode Default
7-4 Receive Low Priority
Rate Control [11:8]
This along with port control 9, bits [7:0] form a 12-bit
field to determine how many “32Kbps” low priority
blocks can be received (in a unit of 4K bytes in a one
second period).
R/W 0
3-0 Receive High Priority
Rate Control [11:8]
This along with port control 8, bits [7:0] form a 12-bit
field to determine how many “32Kbps” high priority
blocks can be received (in a unit of 4K bytes in a one
second period).
R/W 0
Register 27 (0x1B): Port 1 Control 11
Register 43 (0x2B): Port 2 Cont rol 11
Register 59 (0x3B): Port 3 Cont rol 11
Register 75 (0x4B): Port 4 Cont rol 11
Register 91 (0x5B): Port 5 Cont rol 11
Address Name Description Mode Default
7 Receive Differential
Priority Rate Control
1, If bit 6 is also ‘1’ this will enable receive rate control
for this port on low priority packets at the low priority
rate. If bit 5 is also ‘1’, this will enable receive rate
control on high priority packets at the high priority rate.
0, receive rate control will be based on the low priority
rate for all packets on this port.
R/W 0
6 Low Priority Receive
Rate Control Enable
1, enable port’s low priority receive rate control feature.
0, disable port’s low priority receive rate control.
R/W 0
5 High Priority Receive
Rate Control Enable
1, if bit 7 is also ‘1’ this will enable the port’s high
priority receive rate control feature. If bit 7 is a ‘0’ and
bit 6 is a ‘1’, all receive packets on this port will be rate
controlled at the low priority rate.
0, disable port’s high priority receive rate control
feature.
R/W 0
4 Low Priority Receive
Rate Flow Control Enable
1, flow control may be asserted if the port’s low priority
receive rate is exceeded.
0, flow control is not asserted if the port’s low priority
receive rate is exceeded.
R/W 0
Micrel, Inc. KS8995MA/FQ
Semptember 2008 53 M9999-091508
Address Name Description Mode Default
3 High Priority Receive
Rate Flow Control Enable
1, flow control may be asserted if the port’s high priority
receive rate is exceeded. To use this, differential
receive rate control must be on.
0, flow control is not asserted if the port’s high priority
receive rate is exceeded.
R/W 0
2 Transmit Differential
Priority Rate Control
1, transmit rate control on both high and low priority
packets based on the rate counters defined by the high
and low priority packets respectively.
0, transmit rate control on any packets. The rate
counters defined in low priority will be used.
R/W 0
1 Low Priority Transmit
Rate Control Enable
1, enable the port’s low priority transmit rate control
feature.
0, disable the port’s low priority transmit rate control
feature.
R/W 0
0 High Priority Transmit
Rate Control Enable
1, enable the port’s high priority transmit rate control
feature.
0, disable the port’s high priority transmit rate control
feature.
R/W 0
Register 28 (0x1C): Port 1 Control 12
Register 44 (0x2C): Port 2 Control 12
Register 60 (0x3C): Port 3 Control 12
Register 76 (0x4C): Port 4 Control 12
Register 92 (0x5C): Port 5 Control 12
Address Name Description Mode Default
7 Disable Auto-Negotiation 1, disable auto-negotiation, speed and duplex are
decided by bit 6 and 5 of the same register.
0, auto-negotiation is on.
R/W 0
6 Forced Speed 1, forced 100BT if AN is disabled (bit 7).
0, forced 10BT if AN is disabled (bit 7).
R/W 1
5 Forced Duplex 1, forced full-duplex if (1) AN is disabled or (2) AN is
enabled but failed.
0, forced half-duplex if (1) AN is disabled or (2) AN is
enabled but failed.
R/W 0 For port 4 only,
there is a special
configure pin to
set the default pin
PCRS strap
option. Pull-down
(0): Force half-
duplex. Pull-up
(1): Force full-
duplex. Note:
PCRS has
internal pull down.
4 Advertised Flow Control
Capability
1, advertise flow control capability.
0, suppress flow control capability from transmission to
link partner.
R/W 1
3 Advertised 100BT Full-
Duplex Capability
1, advertise 100BT full-duplex capability.
0, suppress 100BT full-duplex capability from
transmission to link partner.
R/W 1
2 Advertised 100BT Half-
Duplex Capability
1, advertise 100BT half-duplex capability.
0, suppress 100BT half-duplex capability from
transmission to link partner.
R/W 1
1 Advertised 10BT Full-
Duplex Capability
1, advertise 10BT full-duplex capability.
0, suppress 10BT full-duplex capability from
transmission to link partner.
R/W 1
Micrel, Inc. KS8995MA/FQ
Semptember 2008 54 M9999-091508
Address Name Description Mode Default
0 Advertised 10BT Half-
Duplex Capability
1, advertise 10BT half-duplex capability.
0, suppress 10BT half-duplex capability from
transmission to link partner.
R/W 1
Note:
Port Control 12 and 13, and Port Status 0 contents can be accessed by MIIM (MDC/MDIO) interface via the standard MIIM register definition.
Register 29 (0x1D): Port 1 Control 13
Register 45 (0x2D): Port 2 Control 13
Register 61 (0x3D): Port 3 Control 13
Register 77 (0x4D): Port 4 Control 13
Register 93 (0x5D): Port 5 Control 13
Address Name Description Mode Default
7 LED Off 1, turn off all port’s LEDs (LEDx_2, LEDx_1, LEDx_0,
where “x” is the port number). These pins will be driven
high if this bit is set to one.
0, normal operation.
R/W 0
6 Txids 1, disable port’s transmitter.
0, normal operation.
R/W 0
5 Restart AN 1, restart auto-negotiation. 0 = normal operation. R/W 0
4 Disable far End fault 1, disable far end fault detection and pattern
transmission.
0, enable far end fault detection and pattern
transmission.
R/W 0
3 Power Down 1, power down.
0, normal operation.
R/W 0
2 Disable Auto MDI/MDI-X 1, disable auto MDI/MDI-X function.
0, enable auto MDI/MDI-X function.
R/W 0
1 Forced MDI 1, if auto MDI/MDI-X is disabled, force PHY into MDI
mode.
0, MDIX mode.
R/W 0
0 MAC Loopback 1, perform MAC loopback.
0, normal operation.
R/W 0
Register 30 (0x1E): Port 1 Status 0
Register 46 (0x2E): Port 2 Status 0
Register 62 (0x3E): Port 3 Status 0
Register 78 (0x4E): Port 4 Status 0
Register 94 (0x5E): Port 5 Status 0
Address Name Description Mode Default
7 MDIX Status 1, MDI.
0, MDI-X.
RO 0
6 AN Done 1, AN done.
0, AN not done.
RO 0
5 Link Good 1, link good.
0, link not good.
RO 0
4 Partner Flow Control
Capability
1, link partner flow control capable.
0, link partner not flow control capable.
RO 0
3 Partner 100BT Full-
Duplex Capability
1, link partner 100BT full-duplex capable.
0, link partner not 100BT full-duplex capable.
RO 0
Micrel, Inc. KS8995MA/FQ
Semptember 2008 55 M9999-091508
Address Name Description Mode Default
2 Partner 100BT Half-
Duplex Capability
1, link partner 100BT half-duplex capable.
0, link partner not 100BT half-duplex capable.
RO 0
1 Partner 10BT Full-Duplex
Capability
1, link partner 10BT full-duplex capable.
0, link partner not 10BT full-duplex capable.
RO 0
0 Partner 10BT Half-Duplex
Capability
1, link partner 10BT half-duplex capable.
0, link partner not 10BT half-duplex capable.
RO 0
Register 31 (0x1F): Port 1 Control 14
Register 47 (0x2F): Port 2 Control 14
Register 63 (0x3F): Port 3 Control 14
Register 79 (0x4F): Port 4 Control 14
Register 95 (0x5F): Port 5 Control 14
Address Name Description Mode Default
7 PHY Loopback 1, perform PHY loopback, i.e. loopback MAC’s Tx back
to Rx.
0, normal operation.
R/W 0
6 Remote Loopback 1, perform remote loopback, i.e. loopback PHY’s Rx
back to Tx.
0, normal operation.
R/W 0
5 PHY Isolate 1, electrical isolation of PHY from MII and TX+/TX-.
0, normal operation.
R/W 0
4 Soft Reset 1, PHY soft reset.
0, normal operation.
R/W 0
3 Force Link 1, force link in the PHY.
0, normal operation.
R/W 0
2-1 Reserved N/A RO 0
0 far End fault 1, far end fault status detected.
0, no far end fault status detected.
RO 0
Advanced Control Registers
The IPv4 TOS priority control registers implement a fully decoded 64 bit differentiated services code point (DSCP)
register used to determine priority from the 6 bit TOS field in the IP header. The most significant 6 bits of the TOS
field are fully decoded into 64 possibilities, and the singular code that results is compared against the corresponding
bit in the DSCP register. If the register bit is a 1, the priority is high; if it is a 0, the priority is low.
Address Name Description Mode Default
Register 96 (0x60): TOS Priority Control Re gister 0
7-0 DSCP[63:56] R/W 00000000
Register 97 (0x61): TOS Priority Control Re gister 1
7-0 DSCP[55:48] R/W 00000000
Register 98 (0x62): TOS Priority Control Re gister 2
7-0 DSCP[47:40] R/W 00000000
Register 99 (0x63): TOS Priority Control Re gister 3
7-0 DSCP[39:32] R/W 00000000
Register 100 (0x64): TOS Priority Control Register 4
7-0 DSCP[31:24] R/W 00000000
Micrel, Inc. KS8995MA/FQ
Semptember 2008 56 M9999-091508
Address Name Description Mode Default
Register 101 (0x65): TOS Priority Control Register 5
7-0 DSCP[23:16] R/W 00000000
Register 102 (0x66): TOS Priority Control Register 6
7-0 DSCP[15:8] R/W 00000000
Register 103 (0x67): TOS Priority Control Register 7
7-0 DSCP[7:0] R/W 00000000
Registers 104 to 109 define the switching engine’s MAC address. This 48-bit address is used as the source address in MAC pause control frames.
Address Name Description Mode Default
Register 104 (0x68): MAC Address Register 0
7-0 MACA[47:40] R/W 0x00
Register 105 (0x69): MAC Address Register 1
7-0 MACA[39:32] R/W 0x10
Register 106 (0x6A): MAC Address Register 2
7-0 MACA[31:24] R/W 0xA1
Register 107 (0x6B): MAC Address Register 3
7-0 MACA[23:16] R/W 0xff
Register 108 (0x6C): MAC Address Register 4
7-0 MACA[15:8] R/W 0xff
Register 109 (0X6D): MAC Address R egister 5
7-0 MACA[7:0] R/W 0xff
Use registers 110 and 111 to read or write data to the static MAC address table, VLAN table, dynamic address table, or the MIB counters.
Address Name Description Mode Default
Register 110 (0x6E): Indirect Access Control 0
7-5 Reserved Reserved. R/W 000
4 Read High Write Low 1, read cycle.
0, write cycle.
R/W 0
3-2 Table Select 00 = static mac address table selected.
01 = VLAN table selected.
10 = dynamic address table selected.
11 = MIB counter selected.
R/W 0
1-0 Indirect Address High Bit 9-8 of indirect address. R/W 00
Register 111 (0x6F): Indirect Access Control 1
7-0 Indirect Address Low Bit 7-0 of indirect address. R/W 00000000
Note:
Write to Register 111 will actually trigger a command. Read or write access will be decided by bit 4 of Register 110.
Address Name Description Mode Default
Register 112 (0x70): Indirect Data Register 8
68-64 Indirect Data Bit 68-64 of indirect data. R/W 00000
Micrel, Inc. KS8995MA/FQ
Semptember 2008 57 M9999-091508
Address Name Description Mode Default
Register 113 (0x71): Indirect Data Register 7
63-56 Indirect Data Bit 63-56 of indirect data. R/W 00000000
Register 114 (0x72): Indirect Data Register 6
55-48 Indirect Data Bit 55-48 of indirect data. R/W 00000000
Register 115 (0x73): Indirect Data Register 5
47-40 Indirect Data Bit 47-40 of indirect data. R/W 00000000
Register 116 (0x74): Indirect Data Register 4
39-32 Indirect Data Bit 39-32 of indirect data. R/W 00000000
Register 117 (0x75): Indirect Data Register 3
31-24 Indirect Data Bit of 31-24 of indirect data R/W 00000000
Register 118 (0x76): Indirect Data Register 2
23-16 Indirect Data Bit 23-16 of indirect data. R/W 00000000
Register 119 (0x77): Indirect Data Register 1
15-8 Indirect Data Bit 15-8 of indirect data. R/W 00000000
Register 120 (0x78): Indirect Data Register 0
7-0 Indirect Data Bit 7-0 of indirect data. R/W 00000000
Do not write or read to/from Registers 121 to 127. Doing so may prevent proper operation. Micrel internal testing only.
Address Name Description Mode Default
Register 121 (0x79): Digital Testing Status 0
7-0 Factory Testing Reserved. Qm_split status RO 0x0
Register 122 (0x7A): Digital T esting Status 1
7-0 Factory Testing Reserved. Dbg[7:0] RO 0x0
Register 123 (0x7B): Digital Testing Control 0
7-0 Factory Testing Reserved. Dbg[12:8] R/W 0x0
Register 124 (0x7C): Digital Testing Control 1
7-0 Factory Testing Reserved. R/W 0x0
Register 125 (0x7D): Analog T esting Control 0
7-0 Factory Testing Reserved. R/W 0x0
Register 126 (0x7E): Analog Testing Control 1
7-0 Factory Testing Reserved. R/W 0x0
Register 127 (0x7F): Analog T esting Status
7-0 Factory Testing Reserved. RO 0x0
Micrel, Inc. KS8995MA/FQ
Semptember 2008 58 M9999-091508
Static MAC Address
KS8995MA/FQ has a static and a dynamic address table. When a DA look-up is requested, both tables will be
searched to make a packet forwarding decision. When an SA look-up is requested, only the dynamic table is
searched for aging, migration, and learning purposes. The static DA look-up result will have precedence over the
dynamic DA look-up result. If there are DA matches in both tables, the result from the static table will be used. The
static table can only be accessed and controlled by an external SPI master (usually a processor). The entries in the
static table will not be aged out by KS8995MA/FQ. An external device does all addition, modification and deletion.
Note:
Register bit assignments are different for static MAC table reads and static MAC table write, as shown in the two tables below.
Address Name Description Mode Default
Format of Static MAC Table for Reads (8 e n tries)
60-57 FID Filter VLAN ID, representing one of the 16 active
VLANs
RO 0000
56 Use FID 1, use (FID+MAC) to look-up in static table.
0, use MAC only to look-up in static table.
RO 0
55 Reserved Reserved. RO N/A
54 Override 1, override spanning tree “transmit enable = 0” or
“receive enable = 0* setting. This bit is used for
spanning tree implementation.
0, no override.
RO 0
53 Valid 1, this entry is valid, the look-up result will be used.
0, this entry is not valid.
RO 0
52-48 Forwarding Ports The 5 bits control the forward ports, example:
00001, forward to port 1
00010, forward to port 2
…..
10000, forward to port 5
00110, forward to port 2 and port 3
11111, broadcasting (excluding the ingress port)
RO 00000
47-0 MAC Address 48 bit MAC address. RO 0x0
Format of Static MAC Table for Writes (8 entries)
59-56 FID Filter VLAN ID, representing one of the 16 active
VLANs.
W 0000
55 Use FID 1, use (FID+MAC) to look-up in static table.
0, use MAC only to look-up in static table.
W 0
54 Override 1, override spanning tree “transmit enable = 0” or
“receive enable = 0” setting. This bit is used for
spanning tree implementation.
0, no override.
W 0
53 Valid 1, this entry is valid, the look-up result will be used.
0, this entry is not valid.
W 0
52-48 Forwarding Ports The 5 bits control the forward ports, example:
00001, forward to port 1
00010, forward to port 2
.....
10000, forward to port 5
00110, forward to port 2 and port 3
11111, broadcasting (excluding the ingress port)
W 00000
47-0 MAC Address 48-bit MAC address. W 0x0
Table 10. Static MAC Address Table
Micrel, Inc. KS8995MA/FQ
Semptember 2008 59 M9999-091508
Examples:
(1) Static Address Table Read (read the 2nd entry)
Write to Register 110 with 0x10 (read static table selected)
Write to Register 111 with 0x1 (trigger the read operation)
Then
Read Register 113 (60-56)
Read Register 114 (55-48)
Read Register 115 (47-40)
Read Register 116 (39-32)
Read Register 117 (31-24)
Read Register 118 (23-16)
Read Register 119 (15-8)
Read Register 120 (7-0)
(2) Static Address Table Write (write the 8th entry)
Write to Register 110 with 0x10 (read static table selected)
Write Register 113 (59-56)
Write Register 114 (55-48)
Write Register 115 (47-40)
Write Register 116 (39-32)
Write Register 117 (31-24)
Write Register 118 (23-16)
Write Register 119 (15-8)
Write Register 120 (7-0)
Write to Register 110 with 0x00 (write static table selected)
Write to Register 111 with 0x7 (trigger the write operation)
Micrel, Inc. KS8995MA/FQ
Semptember 2008 60 M9999-091508
VLAN Address
The VLAN table is used for VLAN table look-up. If 802.1q VLAN mode is enabled (Register 5 bit 7 = 1), this table is
used to retrieve VLAN information that is associated with the ingress packet. The information includes FID (filter ID),
VID (VLAN ID), and VLAN membership described below:
Address Name Description Mode Default
Format of Static VL AN Table (16 entries)
21 Valid 1, the entry is valid.
0, entry is invalid.
R/W 1
20-16 Membership Specify which ports are members of the VLAN.
If a DA look-up fails (no match in both static and
dynamic tables), the packet associated with this VLAN
will be forwarded to ports specified in this field.
E.g., 11001 means port 5, 4, and 1 are in this VLAN.
R/W 11111
15-12 FID Filter ID. KS8995MA/FQ supports 16 active VLANs
represented by these four bit fields. FID is the mapped
ID. If 802.1q VLAN is enabled, the look-up will be
based on FID+DA and FID+SA.
R/W 0
11-0 VID IEEE 802.1q 12 bit VLAN ID. R/W 1
Table 11. VLAN Table
If 802.1q VLAN mode is enabled, KS8995MA/FQ assigns a VID to every ingress packet. If the packet is untagged or
tagged with a null VID, the packet is assigned with the default port VID of the ingress port. If the packet is tagged with
non-null VID, the VID in the tag is used. The look-up process starts from the VLAN table look-up. If the VID is not
valid, the packet is dropped and no address learning occurs. If the VID is valid, the FID is retrieved. The FID+DA and
FID+SA lookups are performed. The FID+DA look-up determines the forwarding ports. If FID+DA fails, the packet is
broadcast to all the members (excluding the ingress port) of the VLAN. If FID+SA fails, the FID+SA is learned.
Examples:
(1) VLAN Table Read (read the 3rd entry)
Write to Register 110 with 0x14 (read VLAN table selected)
Write to Register 111 with 0x2 (trigger the read operation)
Then
Read Register 118 (VLAN table bits 21-16)
Read Register 119 (VLAN table bits 15-8)
Read Register 120 (VLAN table bits 7-0)
(2) VLAN Table Write (write the 7th entry)
Write to Register 118 (VLAN table bits 21-16)
Write to Register 119 (VLAN table bits 15-8)
Write to Register 120 (VLAN table bits 7-0)
Write to Register 110 with 0x04 (write VLAN table selected)
Write to Register 111 with 0x6 (trigger the write operation)
Note:
The sequence of the writing entries should start from entry 0. Improper sequence of the VLAN enties could cause the VLAN to be non-functional.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 61 M9999-091508
Dynamic MAC Address
This table is read only. The contents are maintained by the KS8995MA/FQ only.
Address Name Description Mode Default
Format of Dynamic MAC Address Table (1K entries)
68 MAC Empty 1, there is no valid entry in the table.
0, there are valid entries in the table.
RO 1
67-58 No of Valid Entries Indicates how many valid entries in the table.
0x3ff means 1K entries
0x1 means 2 entries
0x0 and bit 68 = 0: means 1 entry
0x0 and bit 68 = 1: means 0 entry
RO 0
57-56 Time Stamp 2-bit counters for internal aging RO
55 Data Ready 1, The entry is not ready, retry until this bit is set to 0.
0, The entry is ready.
RO
54-52 Source Port The source port where FID+MAC is learned.
000 port 1
001 port 2
010 port 3
011 port 4
100 port 5
RO 0x0
51-48 FID Filter ID. RO 0x0
47-0 MAC Address 48-bit MAC address. RO 0x0
Table 12. Dynamic M AC Address Table
Examples:
(1) Dynamic MAC Address Table Read (read the 1st entry), and retrieve the MAC table size
Write to Register 110 with 0x18 (read dynamic table selected)
Write to Register 111 with 0x0 (trigger the read operation)
Then
Read Register 112 (68-64)
Read Register 113 (63-56); // the above two registers show # of entries
Read Register 114 (55-48) // if bit 55 is 1, restart (reread) from this register
Read Register 115 (47-40)
Read Register 116 (39-32)
Read Register 117 (31-24)
Read Register 118 (23-16)
Read Register 119 (15-8)
Read Register 120 (7-0)
(2) Dynamic MAC Address Table Read (read the 257th entry), without retrieving # of entries information
Write to Register 110 with 0x19 (read dynamic table selected)
Write to Register 111 with 0x1 (trigger the read operation)
Then
Read Register 114 (55-48) // if bit 55 is 1, restart (reread) from this register
Read Register 115 (47-40)
Read Register 116 (39-32)
Read Register 117 (31-24)
Read Register 118 (23-16)
Read Register 119 (15-8)
Read Register 120 (7-0)
Micrel, Inc. KS8995MA/FQ
Semptember 2008 62 M9999-091508
MIB Counters
The MIB counters are provided on per port basis. The indirect memory is as below:
For Port 1
Offset Counter Name Description
0x0 RxLoPriorityByte Rx lo-priority (default) octet count including bad packets.
0x1 RxHiPriorityByte Rx hi-priority octet count including bad packets.
0x2 RxUndersizePkt Rx undersize packets w/good CRC.
0x3 RxFragments Rx fragment packets w/bad CRC, symbol errors or alignment errors.
0x4 RxOversize Rx oversize packets w/good CRC (max: 1536 or 1522 bytes).
0x5 RxJabbers Rx packets longer than 1522B w/either CRC errors, alignment errors, or symbol errors (depends
on max packet size setting) or Rx packets longer than 1916B only.
0x6 RxSymbolError Rx packets w/ invalid data symbol and legal preamble, packet size.
0x7 RxCRCerror Rx packets within (64,1522) bytes w/an integral number of bytes and a bad CRC (upper limit
depends on max packet size setting).
0x8 RxAlignmentError Rx packets within (64,1522) bytes w/a non-integral number of bytes and a bad CRC (upper limit
depends on max packet size setting).
0x9 RxControl8808Pkts The number of MAC control frames received by a port with 88-08h in EtherType field.
0xA RxPausePkts The number of PAUSE frames received by a port. PAUSE frame is qualified with EtherType (88-
08h), DA, control opcode (00-01), data length (64B min), and a valid CRC.
0xB RxBroadcast Rx good broadcast packets (not including errored broadcast packets or valid multicast packets).
0xC RxMulticast Rx good multicast packets (not including MAC control frames, errored multicast packets or valid
broadcast packets).
0xD RxUnicast Rx good unicast packets.
0xE Rx64Octets Total Rx packets (bad packets included) that were 64 octets in length.
0xF Rx65to127Octets Total Rx packets (bad packets included) that are between 65 and 127 octets in length.
0x10 Rx128to255Octets Total Rx packets (bad packets included) that are between 128 and 255 octets in length.
0x11 Rx256to511Octets Total Rx packets (bad packets included) that are between 256 and 511 octets in length.
0x12 Rx512to1023Octets Total Rx packets (bad packets included) that are between 512 and 1023 octets in length.
0x13 Rx1024to1522Octets Total Rx packets (bad packets included) that are between 1024 and 1522 octets in length (upper
limit depends on max packet size setting).
0x14 TxLoPriorityByte Tx lo-priority good octet count, including PAUSE packets.
0x15 TxHiPriorityByte Tx hi-priority good octet count, including PAUSE packets.
0x16 TxLateCollision The number of times a collision is detected later than 512 bit-times into the Tx of a packet.
0x17 TxPausePkts The number of PAUSE frames transmitted by a port.
0x18 TxBroadcastPkts Tx good broadcast packets (not including errored broadcast or valid multicast packets).
0x19 TxMulticastPkts Tx good multicast packets (not including errored multicast packets or valid broadcast packets).
0x1A TxUnicastPkts Tx good unicast packets.
0x1B TxDeferred Tx packets by a port for which the 1st Tx attempt is delayed due to the busy medium.
0x1C TxTotalCollision Tx total collision, half-duplex only.
0x1D TxExcessiveCollision A count of frames for which Tx fails due to excessive collisions.
0x1E TxSingleCollision Successfully Tx frames on a port for which Tx is inhibited by exactly one collision.
0x1F TxMultipleCollision Successfully Tx frames on a port for which Tx is inhibited by more than one collision.
Table 13. Port-1 MIB Counter Indirect Memory Offsets
Micrel, Inc. KS8995MA/FQ
Semptember 2008 63 M9999-091508
For port 2, the base is 0x20, same offset definition (0x20-0x3 f)
For port 3, the base is 0x40, same offset definition (0x40-0x5 f)
For port 4, the base is 0x60, same offset definition (0x60-0x7 f)
For port 5, the base is 0x80, same offset definition (0x80-0x9 f)
Address Name Description Mode Default
Format of Per Port MIB Counters (16 entries)
31 Overflow 1, Counter overflow.
0, No Counter overflow.
RO 0
30 Count Valid 1, Counter value is valid.
0, Counter value is not valid.
RO 0
29-0 Counter Values Counter value. RO 0
Offset Counter Name Description
0x100 Port1 Tx Drop Packets Tx packets dropped due to lack of resources.
0x101 Port2 Tx Drop Packets Tx packets dropped due to lack of resources.
0x102 Port3 Tx Drop Packets Tx packets dropped due to lack of resources.
0x103 Port4 Tx Drop Packets Tx packets dropped due to lack of resources.
0x104 Port5 Tx Drop Packets Tx packets dropped due to lack of resources.
0x105 Port1 Rx Drop Packets Rx packets dropped due to lack of resources.
0x106 Port2 Rx Drop Packets Rx packets dropped due to lack of resources.
0x107 Port3 Rx Drop Packets Rx packets dropped due to lack of resources.
0x108 Port4 Rx Drop Packets Rx packets dropped due to lack of resources.
0x109 Port5 Rx Drop Packets Rx packets dropped due to lack of resources.
Table 14. All Port Dropped Packet MIB Counters
Address Name Description Mode Default
Format of All Port Dropped Packet MIB Counters
30-16 Reserved Reserved. N/A N/A
15-0 Counter Values Counter value. RO 0
Note:
All port dropped packet MIB counters do not indicate overflow or validity; therefore the application must keep track of overflow and valid
conditions.
Examples:
(1) MIB counter read (read port 1 rx 64 counter)
Write to Register 110 with 0x1c (read MIB counters selected)
Write to Register 111 with 0xe (trigger the read operation)
Then
Read Register 117 (counter value 31-24)
// If bit 31 = 1, there was a counter overflow
// If bit 30 = 0, restart (reread) from this register
Read Register 118 (counter value 23-16)
Read Register 119 (counter value 15-8)
Read Register 120 (counter value 7-0)
Micrel, Inc. KS8995MA/FQ
Semptember 2008 64 M9999-091508
(2) MIB counter read (read port 2 rx 64 counter)
Write to Register 110 with 0x1c (read MIB counter selected)
Write to Register 111 with 0x2e (trigger the read operation)
Then
Read Register 117 (counter value 31-24)
//If bit 31 = 1, there was a counter overflow
//If bit 30 = 0, restart (reread) from this register
Read Register 118 (counter value 23-16)
Read Register 119 (counter value 15-8)
Read Register 120 (counter value 7-0)
(3) MIB counter read (read port 1 tx drop packets)
Write to Register 110 with 0x1d
Write to Register 111 with 0x00
Then
Read Register 119 (counter value 15-8)
Read Register 120 (counter value 7-0)
Note:
To read out all the counters, the best performance over the SPI bus is (160+3) × 8 × 200 = 260ms, where there are 160 registers, 3 overhead, 8
clocks per access, at 5MHz. In the heaviest condition, the byte counter will overflow in 2 minutes. It is recommended that the software read all the
counters at least every 30 seconds. The per port MIB counters are designed as “read clear.” A per port MIB counter will be cleared after it is
accessed. All port dropped packet MIB counters are not cleared after they are accessed. The application needs to keep track of overflow and valid
conditions on these counters.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 65 M9999-091508
MIIM Registers
All the registers defined in this section can be also accessed via the SPI interface. Note: different mapping
mechanisms used for MIIM and SPI. The “PHYAD” defined in IEEE is assigned as “0x1” for port 1, “0x2” for port 2,
“0x3” for port 3, “0x4” for port 4, and “0x5” for port 5. The “REGAD” supported are 0,1,2,3,4,5.
Address Name Description Mode Default
Register 0: MII Control
15 Soft Reset 1, PHY soft reset.
0, Normal operation.
R/W 0
14 Loop Back 1, Loop back mode (loopback at MAC).
0, Normal operation.
W 0
13 Force 100 1, 100Mbps.
0, 10Mbps.
R/W 1
12 AN Enable 1, Auto-negotiation enabled.
0, Auto-negotiation disabled.
R/W 1
11 Power Down 1, Power down.
0, Normal operation.
R/W 0
10 PHY Isolate 1, Electrical PHY isolation of PHY from Tx+/Tx-.
0, Normal operation.
R/W 0
9 Restart AN 1, Restart Auto-negotiation.
0, Normal operation.
R/W 0
8 Force Full Duplex 1, Full duplex.
0, Half duplex.
R/W 0
7 Collision Test Not supported. RO 0
6 Reserved RO 0
5 Reserved RO 0
4 Force MDI 1, Force MDI.
0, Normal operation.
R/W 0
3 Disable Auto MDI/MDI-X 1, Disable auto MDI/MDI-X.
0, Normal operation.
R/W 0
2 Disable far End fault 1, Disable far end fault detection.
0, Normal operation.
R/W 0
1 Disable Transmit 1, Disable transmit.
0, Normal operation.
R/W 0
0 Disable LED 1, Disable LED.
0, Normal operation.
R/W 0
Register 1: MII Status
15 T4 Capable 0, Not 100 BASET4 capable. RO 0
14 100 Full Capable 1, 100BASE-TX full-duplex capable.
0, Not capable of 100BASE-TX full-duplex.
RO 1
13 100 Half Capable 1, 100BASE-TX half-duplex capable.
0, Not 100BASE-TX half-duplex capable.
RO 1
12 10 Full Capable 1, 10BASE-T full-duplex capable.
0, Not 10BASE-T full-duplex capable.
RO 1
11 10 Half Capable 1, 10BASE-T half-duplex capable.
0, 10BASE-T half-duplex capable.
RO 1
10-7 Reserved RO 0
6 Preamble Suppressed Not supported. RO 0
5 AN Complete 1, Auto-negotiation complete.
0, Auto-negotiation not completed.
RO 0
4 far End fault 1, far end fault detected.
0, No far end fault detected.
RO 0
Micrel, Inc. KS8995MA/FQ
Semptember 2008 66 M9999-091508
Address Name Description Mode Default
3 AN Capable 1, Auto-negotiation capable.
0, Not auto-negotiation capable.
RO 1
2 Link Status 1, Link is up.
0, Link is down.
RO 0
1 Jabber Test Not supported. RO 0
0 Extended Capable 0, Not extended register capable. RO 0
Register 2: PHYID HIGH
15-0 Phyid High High order PHYID bits. RO 0x0022
Register 3: PHYID LOW
15-0 Phyid Low Low order PHYID bits. RO 0x1450
Register 4: Advertisement Ability
15 Next Page Not supported. RO 0
14 Reserved RO 0
13 Remote fault Not supported. RO 0
12-11 Reserved RO 0
10 Pause 1, Advertise pause ability.
0, Do not advertise pause ability.
R/W 1
9 Reserved R/W 0
8 Adv 100 Full 1, Advertise 100 full-duplex ability.
0, Do not advertise 100 full-duplex ability.
R/W 1
7 Adv 100 Half 1, Advertise 100 half-duplex ability.
0, Do not advertise 100 half-duplex ability.
R/W 1
6 Adv 10 Full 1, Advertise 10 full-duplex ability.
0, Do not advertise 10 full-duplex ability.
R/W 1
5 Adv 10 Half 1, Advertise 10 half-duplex ability.
0, Do not advertise 10 half-duplex ability.
R/W 1
4-0 Selector Field 802.3 RO 00001
Register 5: Link Partner Ability
15 Next Page Not supported. RO 0
14 LP ACK Not supported. RO 0
13 Remote fault Not supported. RO 0
12-11 Reserved RO 0
10 Pause Link partner pause capability. RO 0
9 Reserved RO 0
8 Adv 100 Full Link partner 100 full capability. RO 0
7 Adv 100 Half Link partner 100 half capability. RO 0
6 Adv 10 Full Link partner 10 full capability. RO 0
5 Adv 10 Half Link partner 10 half capability. RO 0
4-0 Reserved RO 00001
Micrel, Inc. KS8995MA/FQ
Semptember 2008 67 M9999-091508
Absolute Maximum Ratings(1)
Supply Voltage
(VDDAR, VDDAP, VDDC) .......................–0.5V to +2.4V
(VDDAT, VDDIO) .................................–0.5V to +4.0V
Input Voltage ........................................–0.5V to +4.0V
Output Voltage .....................................–0.5V to +4.0V
Lead Temperature (soldering, 10 sec.)..............270°C
Storage Temperature (TS)................ –55°C to +150°C
Operating Ratings(2)
Supply Voltage
(VDDAR, VDDAP, VDDC)....................... +1.7V to +1.9V
(VDDAT) ..........+3.15V to +3.45V or +2.4V to +2.6V
(VDDIO)........................................ +3.15V to +3.45V
Ambient Temperature (TA)
Commercial .................................... –0°C to +70°C
Industrial.......................................–40°C to +85°C
Package Thermal Resistance(3)
PQFP (θJA) No Air Flow........................42.91°C/W
PQFP (θJC) No Air Flow ..........................19.6°C/W
Electrical Characteristics(4, 5)
Symbol Parameter Condition Min Typ Max Units
100BASE-TX Operation—All Ports 100% Utilization
IDX 100BASE-TX (Transmitter) VDDAT 20 28 mA
IDDC 100BASE-TX (Digital Core/PLL+ Analog Rx) VDDC, VDDAP, VDDAR 157 230 mA
IDDIO 100BASE-TX (Digital IO) VDDIO 17 30 mA
10BASE-T Operation —All Ports 100% Utilization
IDX 10BASE-T (Transmitter) VDDAT 15 25 mA
IDDC 10BASE-T (Digital Core + Analog Rx) VDDC, VDDAP 102 180 mA
IDDIO 10BASE-T (Digital IO) VDDIO 6 15 mA
Auto-Negotiation Mode
IDX 10BASE-T (Transmitter) VDDAT 25 40 mA
IDDC 10BASE-T (Digital Core + Analog Rx) VDDC, VDDAP 108 180 mA
IDDIO 10BASE-T (Digital IO) VDDIO 17 20 mA
TTL Inputs
VIH Input High Voltage +2.0 V
VIL Input Low Voltage +0.8 V
IIN Input Current (Excluding Pull-up/Pull-down) VIN = GND ~ VDDIO –10 10 µA
TTL Outputs
VOH Output High Voltage IOH = –8mA +2.4 V
VOL Output Low Voltage IOL = 8mA +0.4 V
IOZ Output Tri-State Leakage VIN = GND ~ VDDIO 10 µA
100BASE-TX Transmit (measured differentially after 1:1 transformer)
VO Peak Differential Output Voltage 100Ω termination on the
differential output 0.95 1.05 V
VIMB Output Voltage Imbalance 100Ω termination on the
differential output 2 %
Rise/fall Time 3 5 ns
tr tt Rise/fall Time Imbalance 0 0.5 ns
Duty Cycle Distortion ±0.5 ns
Overshoot 5 %
VSET Reference Voltage of ISET 0.5 V
Output Jitters Peak-to-peak 0.7 1.4 ns
Micrel, Inc. KS8995MA/FQ
Semptember 2008 68 M9999-091508
Symbol Parameter Condition Min Typ Max Units
10BASE-T Recei ve
VSQ Squelch Threshold 5MHz square wave 400 mV
10BASE-T Transmit (measured d ifferentially after 1:1 transformer) VDDAT = 2.5V
VP Peak Differential Output Voltage 100Ω termination on the
differential output 2.3 V
Jitters Added 100Ω termination on the
differential output 16 ns
Rise/fall Times 28 30 ns
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating. Unused inputs must always be tied to an appropriate logic voltage level
(ground to VDD).
3. No heat spreader in package. The thermal junction to ambient (θJA) and the thermal junction to case (θJC) are under air velocity 0m/s.
4. Specification for packaged product only. A single port’s transformer consumes an additional about 40mA for 100Base-TX and 59mA for 10Bese-
T.
5. Measurements were taken with operating ratings.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 69 M9999-091508
Timing Diagrams
SCL
SDA
tcyc1ts1 th1
Receive Timing
Figure 13. EEPROM Interface Input Receive Timing Diagram
SCL
SDA
tcyc1
Transmit Timing
tov1
Figure 14. EEPROM Interface Outpu t Transmit Timing Diagram
Symbol Parameter Min Typ Max Units
tCYC1 Clock Cycle 16384 ns
tS1 Set-Up Time 20 ns
tH1 Hold Time 20 ns
tOV1 Output Valid 4096 4112 4128 ns
Table 14. EEPROM Timing Parameters
Micrel, Inc. KS8995MA/FQ
Semptember 2008 70 M9999-091508
tcyc2ts2 th2
MTXC
MTXEN
MTXD[0]
Receive Timing
Figure 15. SNI Input Timing
MRXC
MRXDV
tcyc2
Transmit Timing
tov2
MRXD[0]
MCOL
Figure 16. SNI Output Timing
Symbol Parameter Min Typ Max Units
tCYC2 Clock Cycle 100 ns
tS2 Set-Up Time 10 ns
tH2 Hold Time 0 ns
tO2 Output Valid 0 3 6 ns
Table 15. SNI Timing Parameters
Micrel, Inc. KS8995MA/FQ
Semptember 2008 71 M9999-091508
Figure 17. MII Received Timing – For 100BASE-T
Symbol Parameter Min Typ Max Units
tP RXC Period 40 ns
tWL RXC Pulse Width 20 ns
tWH RXC Pulse Width 20 ns
tSU RXD [3:0], RXDV Set-up to Rising Edge of RXC 20 ns
tHD RXD [3:0], RXDV Hold from Rising Edge of RXC 20 ns
tRLAT CRS to RXD Latency, 4B or 5B Aligned 60 ns
tod RXD [3:0], RXDV Output Delay from Rising Edge of RCX 18 25 28 ns
Table 16. MII Received Timing Parameters
Micrel, Inc. KS8995MA/FQ
Semptember 2008 72 M9999-091508
Figure 18. MII Transmitted Timing – For 100BASE-T
Symbol Parameter Min Typ Max Units
tSU1 TXD [3:0] Set-up to TXC High 10 ns
tSU2 TXEN Set-up to TXC High 10 ns
tHD1 TXD [3:0] Hold after TXC High 0 ns
tHD2 TXER Hold after TXC High 0 ns
tCRS1 TXEN High to CRS Asserted Latency 40 ns
tCRS2 TXEN Low to CRS De-Asserted Latency 40 ns
Table 17. MII Transmitted Timing Parameters
Micrel, Inc. KS8995MA/FQ
Semptember 2008 73 M9999-091508
SPIQ
SPIC
SPID
SPIS_N
High Impedance
MSB
tCHSL tSLCH
tDVCH
tCHDX
tDLDH
tDHDL
LSB
tCLCH
tCHCL
tSHCH
tCHSH
tSHSL
Figure 19. SPI Input Timing
Symbol Parameter Min Typ Max Units
fC Clock Frequency 5 MHz
tCHSL SPIS_N Inactive Hold Time 90 ns
tSLCH SPIS_N Active Set-Up Time 90 ns
tCHSH SPIS_N Active Hold Time 90 ns
tSHCH SPIS_N Inactive Set-Up Time 90 ns
tSHSL SPIS_N Deselect Time 100 ns
tDVCH Data Input Set-Up Time 20 ns
tCHDX Data Input Hold Time 30 ns
tCLCH Clock Rise Time 1 µs
tCHCL Clock fall Time 1 µs
tDLDH Data Input Rise Time 1 µs
tDHDL Data Input fall Time 1 µs
Table 18. SPI Input Timing Parameters
Micrel, Inc. KS8995MA/FQ
Semptember 2008 74 M9999-091508
SPID
SPIC
SPIQ
SPIS_N
tQLQH
tQHQL
LSB
tCH
tCL tSHQZtCLQV
tCLQX
Figure 20. SPI Output Timing
Symbol Parameter Min Typ Max Units
fC Clock Frequency 5 MHz
tCLQX SPIQ Hold Time 0 0 ns
tCLQV Clock Low to SPIQ Valid 60 ns
tCH Clock High Time 90 ns
tCL Clock Low Time 90 ns
tQLQH SPIQ Rise Time 50 ns
tQHQL SPIQ fall Time 50 ns
tSHQZ SPIQ Disable Time 100 ns
Table 19. SPI Output Timing Parameters
Micrel, Inc. KS8995MA/FQ
Semptember 2008 75 M9999-091508
tsr
tcs tch
trc
Supply
Voltage
RST_N
Strap-In
Value
Strap-In /
Output Pin
Figure 21. Reset Timing
Symbol Parameter Min Typ Max Units
tSR Stable Supply Voltages to Reset High 10 ms
tCS Configuration Set-Up Time 50 ns
tCH Configuration Hold Time 50 ns
tRC Reset to Strap-In Pin Output 50 ns
Table 20. Reset Timing Parameters
Micrel, Inc. KS8995MA/FQ
Semptember 2008 76 M9999-091508
Reset Circuit Diagram
Micrel recommends the following discrete reset circuit as shown in Figure 22 when powering up the KS8895MA device.
For the application where the reset circuit signal comes from another device (e.g., CPU, FPGA, etc), we recommend
the reset circuit as shown in Figure 23.
VCC
R
10k
C
10µF
D1
KS8995MA
RST
D1: 1N4148
Figure 22. Recommended Reset Circuit
VCC
R
10k
D2
C
10µF
D1 CPU/FPGA
RST_OUT_n
KS8995MA
RST
D1, D2: 1N4148
Figure 23. Recommended Circuit for Interfacing with CPU/FPGA Reset
At power-on-reset, R, C, and D1 provide the necessary ramp rise time to reset the Micrel device. The reset out from
CPU/FPGA provides warm reset after power up. It is also recommended to power up the VDD core voltage earlier than
VDDIO voltage. At worst case, the both VDD core and VDDIO voltages should come up at the same time.
Micrel, Inc. KS8995MA/FQ
Semptember 2008 77 M9999-091508
Selection of Isolation Transformer(1)
One simple 1:1 isolation transformer is needed at the line interface. An isolation transformer with integrated common-
mode choke is recommended for exceeding FCC requirements. The following table gives recommended transformer
characteristics.
Characteristics Name Value Test Condition
Turns Ratio 1 CT : 1 CT
Open-Circuit Inductance (min.) 350µH 100mV, 100kHz, 8mA
Leakage Inductance (max.) 0.4µH 1MHz (min.)
Inter-Winding Capacitance (max.) 12pF
D.C. Resistance (max.) 0.9Ω
Insertion Loss (max.) 1.0dB 0MHz to 65MHz
HIPOT (min.) 1500Vrms
Note:
1. The IEEE 802.3u standard for 100BASE-TX assumes a transformer loss of 0.5dB. For the transmit line transformer, insertion loss of up to 1.3dB
can be compensated by increasing the line drive current by means of reducing the ISET resistor value.
The following transformer vendors provide compatible magnetic parts for Micrel’s device:
4-Port Integrated Single Port
Vendor Part
Auto
MDIX Number
of Ports Vendor Part
Auto
MDIX Number of
Ports
Pulse H1164 Yes 4 Pulse H1102 Yes 1
Bel Fuse 558-5999-Q9 Yes 4 Bel Fuse S558-5999-U7 Yes 1
YCL PH406466 Yes 4 YCL PT163020 Yes 1
Transpower HB826-2 Yes 4 Transpower HB726 Yes 1
Delta LF8731 Yes 4 Delta LF8505 Yes 1
LanKom SQ-H48W Yes 4 LanKom LF-H41S Yes 1
Table 21. Qualified Magnetics Vendors
Micrel, Inc. KS8995MA/FQ
Semptember 2008 78 M9999-091508
Package Information
Pin #
128-Pin PQFP (PQ)
Micrel, Inc. KS8995MA/FQ
Semptember 2008 79 M9999-091508
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 faX +1 (408) 474-1000 WEB http:/www.micrel.com
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for
its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a
product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for
surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant
injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk
and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale.
© 2008 Micrel, Incorporated.
