MICREL KSZ8842

KSZ8842-16/32
MQL/MVL/MVLI
2-Port Ethernet Switch with Non-PCI Interface
Data Sheet Rev 1.4
General Description
The KSZ8842-series of 2-port switches includes PCI and
non-PCI CPU interfaces, and are available in 8/16-bit
and 32-bit bus designs (see Ordering Information).
This datasheet describes the KSZ8842M-series of nonPCI CPU interface chips. For information on the
KSZ8842 PCI CPU interface switches, refer to the
KSZ8842P datasheet.
The KSZ8842M is the industry’s first fully managed, 2port switch with a non-PCI CPU interface. It is based on
a proven, 4th generation, integrated Layer-2 switch,
compliant with IEEE 802.3u standards. Also an industrial
temperature grade version of the KSZ8842, the
KSZ8842MQLI, can be ordered (see Ordering
Information).
The KSZ8842M can be configured as a switch or as a
low-latency (≤ 310 nanoseconds) repeater in latencycritical, embedded or industrial Ethernet applications.
For industrial applications, the KSZ8842M can run in
half-duplex mode regardless of the application.
The KSZ8842M offers an extensive feature set that
includes tag/port-based VLAN, quality of service (QoS)
priority management, management information base
(MIB) counters, and CPU control/data interfaces to
effectively address Fast Ethernet applications.
The KSZ8842M contains: Two 10/100 transceivers with
patented, mixed-signal, low-power technology, two
media access control (MAC) units, a direct memory
access (DMA) channel, a high-speed, non-blocking,
switch fabric, a dedicated 1K entry forwarding table, and
an on-chip frame buffer memory.
Functional Diagram
1 K lo o k - u p
E n g in e
1 0 /1 0 0 B a s e T /T X
PHY 1
1 0 /1 0 0
MAC 1
P 2 H P A u to
M D I/M D I-X
1 0 /1 0 0 B a s e T /T X
PHY 2
1 0 /1 0 0
MAC 2
Em bedded
P r o c e s s o r In te r fa c e
N o n -P C I
CPU
Bus
In te r fa c e
U n it
QMU
DMA
C hannel
P 2 L E D [3 :0 ]
TXQ
4KB
C o n tro l
R e g is t e r s
8 , 1 6 , o r 3 2 - b it
G e n e r ic H o s t
In te rfa c e
P 1 L E D [3 :0 ]
RXQ
4KB
S w it c h
H ost
MAC
FIFO, Flow Control, VLAN Tagging ,Priority
P 1 H P A u to
M D I/M D I-X
LED
D r iv e r s
S c h e d u lin g
M anagem ent
B u ffe r
M anagem ent
F ra m e
B u ffe rs
M IB
C o u n te rs
EEPROM
In te rfa c e
E E P R O M I/F
Figure 1. KSZ8842M Functional Diagram
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Features
Switch Management
• Non-blocking switch fabric assures fast packet
delivery by utilizing a 1K entry forwarding table
• Fully compliant with IEEE 802.3u standards
• Full-duplex IEEE 802.3x flow control (Pause) with
force mode option
• Half-duplex back pressure flow control
(see Ordering Information)
• Available in 128-pin PQFP
(optional package: 128-pin LQFP)
• Available in –16 version for 8/16-bit bus support and –
32 version for 32-bit bus support (see Ordering
Information).
Additional Features
Advanced Switch Management
• IEEE 802.1Q VLAN support for up to 16 groups (full
range of VLAN IDs)
• VLAN ID tag/untag options, on a per port basis
• IEEE 802.1p/Q tag insertion or removal on a per port
basis (egress)
• Programmable rate limiting at the ingress and egress
ports
• Broadcast storm protection
• IEEE 802.1d spanning tree protocol support
• MAC filtering function to filter or forward unknown
unicast packets
• Direct forwarding mode enabling the processor to
identify the ingress port and to specify the egress port
• Internet Group Management Protocol (IGMP) v1/v2
snooping support for multicast packet filtering
• IPV6 Multicast Listener Discovery (MLD) snooping
support
In addition to offering all of the features of an integrated
Layer-2 managed switch, the KSZ8842M offers:
• Repeater mode capabilities to allow for cut through in
latency critical industrial Ethernet or embedded
Ethernet applications
• Dynamic buffer memory scheme
– Essential for applications such as Video over IP
where image jitter is unacceptable
• 2-port switch with a flexible 8, 16, or 32-bit generic
host processor interfaces
• Micrel LinkMD™ cable diagnostics to determine cable
length, diagnose faulty cables, and determine
distance-to-fault
• Hewlett Packard (HP) Auto-MDIX crossover with
disable and enable options
• Four priority queues to handle voice, video, data, and
control packets
• Ability to transmit and receive jumbo frame sizes up to
1916 bytes
Monitoring
• Port mirroring/monitoring/sniffing: ingress and/or
egress traffic to any port
• MIB counters for fully compliant statistics gathering –
34 MIB counters per port
• Loopback modes for remote failure diagnostics
Applications
•
•
•
•
Comprehensive Register Access
• Control registers configurable on-the-fly (port-priority,
802.1p/d/Q)
•
•
•
QoS/CoS Packets Prioritization Support
• Per port, 802.1p and DiffServ-based
• Remapping of 802.1p priority field on a per port basis
Power Modes, Packaging, and Power Supplies
• Full-chip hardware power-down (register configuration
not saved) allows low power dissipation
• Per port-based, software power-save on PHY (idle
link detection, register configuration preserved)
• Single power supply: 3.3V
• Commercial Temperature Range: 0oC to +70oC
•
Markets
•
•
•
Fast Ethernet
Embedded Ethernet
Industrial Ethernet
LinkMD is a trademark of Micrel, Inc.
Product names used in this datasheet are for identification purposes only and may be
trademarks of their respective companies.
• Industrial Temperature Range: –40oC to +85oC
November 2005
Video Distribution Systems
High-end Cable, Satellite, and IP set-top boxes
Video over IP
Voice over IP (VoIP) and Analog Telephone Adapters
(ATA)
Industrial Control in Latency Critical Applications
Motion Control
Industrial Control Sensor Devices (Temperature,
Pressure, Levels, and Valves)
Security and Surveillance Cameras
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KSZ8842-16/32 MQL/MVL
Ordering Information
Part Number
Temperature Range
o
o
Package
KSZ8842-16MQL
0 C to 70 C
128-Pin PQFP
KSZ8842-32MQL
0oC to 70oC
128-Pin PQFP
o
o
KSZ8842-16MVL
0 C to 70 C
KSZ8842-32MVL
0oC to 70oC
o
128-Pin LQFP (Available Q4 Samples)
128-Pin LQFP (Available Q4 Samples)
o
KSZ8842-16MVLI
–40 C to +85 C
KSZ8842-16MQL-Eval
Evaluation Board for the KSZ8842-16MQL
128-Pin LQFP (Available Q4 Samples)
Contacts
Location
Address
City, State/Province,
Country
Telephone
Fax
Corporate HQ
2180 Fortune Drive
San Jose, CA 95131 USA
+1 (408) 944-0800
+1 (408) 474-1000
Eastern USA
93 Branch Street
Medford, NJ 08055 USA
+1 (609) 654-0078
+1 (609) 546-0989
Central USA
2425 N.Central Expressway, Suite 351
Richardson, TX 75080 USA
+1 (972) 393-2533
+1 (972) 393-2370
Western USA
2180 Fortune Drive
San Jose, CA 95131 USA
+1 (408) 944-0800
+1 (408) 914-7878
China
Room 712, Block B, Intl. Chamber of
Commerce Bldg., Fuhua Rd 1, Futian
Shenzhen, PR China 518026
+86 (755) 83027618
+86 (755) 83027637
Korea
8F AnnJay Tower Bldg
718-2 Yeoksam-dong, Kangnam-ku
Seoul 135-080 Korea
+82 (2) 538-2380
+82 (2) 538-2381
Taiwan
4F, No. 18, Lane 321, Yang-Guang Street,
Nei-Hu Chu
Taipei, 11468 Taiwan, R.O.C.
+886 (2) 8751-0600
+886 (2) 8751-0746
Singapore
300 Beach Road, #10-07 The Concourse
Singapore 199555
+65-6291-1318
+65-6291-1332
Japan
2-3-1 Minato Mirai, Queen’s Tower A 14F,
Nishi-ku
Yokohama, Kanagawa 220-8543
Japan
+81-45-224-6616
+81-45-224-6716
UK/EMEIA
1st Floor, 3 Lockside Place, Mill Lane
Newbury, Berks RG14 5QS UK
+44 1635 524455
+44 1635 524466
France/Southern
Europe
10, avenue du Quebec, Villebon BP116
Courtaboeuf Cedex 91944 France
+33 (0) 1-6092-4190
+33 (0) 1-6092-4189
New Zealand
Office 2, CML Building
2 Perry Street
Masterton
New Zealand
+ 64-6-378-9799
+ 64-6-378-9599
Revision History
Revision
Date
Summary of Changes
1.0
06/30/05
First released Preliminary Information
1.1
07/19/05
Updated General Description, Functional Diagram, Pin Description and Features.
Added this Revision History Table, Repeater mode and Loopback support sections.
1.2
08/08/05
Updated Tables, timing and body text.
1.3
10/04/05
Updated Power Saving bit description in P1/2PHYCTRL and P1/2SCSLMD registers
1.4
11/01/05
Updated Figure 16/17/18 Asynchronous Timing and Table 24/25/26 parameters, PQFP
package information
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Content
General Description................................................................................................................. 1
Functional Diagram ................................................................................................................. 1
Features .................................................................................................................................... 2
Applications ............................................................................................................................. 2
Markets ..................................................................................................................................... 2
Ordering Information ............................................................................................................... 3
Contacts.................................................................................................................................... 3
Revision History....................................................................................................................... 3
Content ..................................................................................................................................... 4
List of Figures .......................................................................................................................... 8
List of Tables............................................................................................................................ 9
Pin Configuration for KSZ8842-16 Switches (8/16-Bit) ....................................................... 10
Pin Description for KSZ8842-16 Switches (8/16-Bit)........................................................... 11
Pin Configuration for KSZ8842-32 Switches (32-Bit) .......................................................... 16
Pin Description for KSZ8842-32 Switches (32-Bit).............................................................. 17
Functional Description .......................................................................................................... 22
Functional Overview: Physical Layer Transceiver.............................................................. 22
100BASE-TX Transmit......................................................................................................................................................22
100BASE-TX Receive.......................................................................................................................................................22
Scrambler/De-scrambler (100BASE-TX Only) ..................................................................................................................22
10BASE-T Transmit ..........................................................................................................................................................22
10BASE-T Receive ...........................................................................................................................................................22
Power Management..........................................................................................................................................................23
MDI/MDI-X Auto Crossover ..............................................................................................................................................23
Straight Cable.................................................................................................................................................................23
Crossover Cable.............................................................................................................................................................24
Auto Negotiation ...............................................................................................................................................................24
LinkMD Cable Diagnostics ................................................................................................................................................25
Access............................................................................................................................................................................25
Usage .............................................................................................................................................................................26
Functional Overview: MAC and Switch................................................................................ 26
Address Lookup ................................................................................................................................................................26
Learning............................................................................................................................................................................26
Migration ...........................................................................................................................................................................26
Aging.................................................................................................................................................................................26
Forwarding........................................................................................................................................................................27
Switching Engine ..............................................................................................................................................................29
MAC Operation .................................................................................................................................................................29
Inter Packet Gap (IPG) .....................................................................................................................................................29
Back-Off Algorithm............................................................................................................................................................29
Late Collision ....................................................................................................................................................................29
legal Packet Size ..............................................................................................................................................................29
Flow Control......................................................................................................................................................................29
Half-Duplex Backpressure ................................................................................................................................................29
Broadcast Storm Protection ..............................................................................................................................................30
Repeater Mode .................................................................................................................................................................30
Clock Generator................................................................................................................................................................30
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Bus Interface Unit (BIU)......................................................................................................... 30
Asynchronous Interface ....................................................................................................................................................32
Synchronous Interface ......................................................................................................................................................33
Summary ..........................................................................................................................................................................33
BIU Implementation Principles ..........................................................................................................................................34
Queue Management Unit (QMU) ........................................................................................... 35
Transmit Queue (TXQ) Frame Format..............................................................................................................................35
Receive Queue (RXQ) Frame Format ..............................................................................................................................36
Advanced Switch Functions ................................................................................................. 38
Spanning Tree Support.....................................................................................................................................................38
IGMP Support ...................................................................................................................................................................39
“IGMP” Snooping............................................................................................................................................................39
“Multicast Address Insertion” in the Static MAC Table....................................................................................................39
IPv6 MLD Snooping ..........................................................................................................................................................39
Port Mirroring Support.......................................................................................................................................................39
IEEE 802.1Q VLAN Support .............................................................................................................................................40
QoS Priority Support .........................................................................................................................................................40
Port-Based Priority............................................................................................................................................................40
802.1p-Based Priority .......................................................................................................................................................40
DiffServ based Priority ......................................................................................................................................................41
Rate Limiting Support .......................................................................................................................................................41
MAC Filtering Function .....................................................................................................................................................42
Configuration Interface......................................................................................................................................................42
EEPROM Interface ...........................................................................................................................................................42
Loopback Support.............................................................................................................................................................43
Far-end Loopback ..........................................................................................................................................................43
Near-end (Remote) Loopback ........................................................................................................................................43
CPU Interface I/O Registers .................................................................................................. 45
I/O Registers .....................................................................................................................................................................45
Internal I/O Space Mapping ..............................................................................................................................................46
Register Map: Switch & MAC/PHY........................................................................................ 54
Bit Type Definition.............................................................................................................................................................54
Bank 0-63 Bank Select Register (0x0E): BSR (same location in all Banks)......................................................................54
Bank 0 Base Address Register (0x00): BAR.....................................................................................................................54
Bank 0 Bus Error Status Register (0x06): BESR ..............................................................................................................55
Bank 0 Bus Burst Length Register (0x08): BBLR .............................................................................................................55
Bank 1: Reserved .............................................................................................................................................................55
Bank 2 Host MAC Address Register Low (0x00): MARL ..................................................................................................55
Bank 2 Host MAC Address Register Middle (0x02): MARM .............................................................................................56
Bank 2 Host MAC Address Register High (0x04): MARH .................................................................................................56
Bank 3 On-Chip Bus Control Register (0x00): OBCR .......................................................................................................56
Bank 3 EEPROM Control Register (0x02): EEPCR ..........................................................................................................57
Bank 3 Memory BIST INFO Register (0x04): MBIR ..........................................................................................................57
Bank 3 Global Reset Register (0x06): GRR......................................................................................................................57
Bank 3 Bus Configuration Register (0x08): BCFG ............................................................................................................58
Banks 4—15: Reserved ....................................................................................................................................................58
Bank 16 Transmit Control Register (0x00): TXCR ............................................................................................................58
Bank 16 Transmit Status Register (0x02): TXSR..............................................................................................................58
Bank 16 Receive Control Register (0x04): RXCR.............................................................................................................59
Bank 16 TXQ Memory Information Register (0x08): TXMIR .............................................................................................59
Bank 16 RXQ Memory Information Register (0x0A): RXMIR............................................................................................60
Bank 17 TXQ Command Register (0x00): TXQCR ...........................................................................................................60
Bank 17 RXQ Command Register (0x02): RXQCR ..........................................................................................................60
Bank 17 TX Frame Data Pointer Register (0x04): TXFDPR .............................................................................................60
Bank 17 RX Frame Data Pointer Register (0x06): RXFDPR ............................................................................................61
Bank 17 QMU Data Register Low (0x08): QDRL ..............................................................................................................61
Bank 17 QMU Data Register High (0x0A): QDRH ............................................................................................................61
Bank 18 Interrupt Enable Register (0x00): IER.................................................................................................................62
Bank 18 Interrupt Status Register (0x02): ISR..................................................................................................................63
Bank 18 Receive Status Register (0x04): RXSR ..............................................................................................................64
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Bank 18 Receive Byte Counter Register (0x06): RXBC....................................................................................................64
Bank 19 Multicast Table Register 0 (0x00): MTR0............................................................................................................65
Bank 19 Multicast Table Register 1 (0x02): MTR1............................................................................................................65
Bank 19 Multicast Table Register 2 (0x04): MTR2............................................................................................................65
Bank 19 Multicast Table Register 3 (0x06): MTR3............................................................................................................65
Banks 20 – 31: Reserved..................................................................................................................................................65
Bank 32 Switch ID and Enable Register (0x00): SIDER ...................................................................................................66
Bank 32 Switch Global Control Register 1 (0x02): SGCR1...............................................................................................66
Bank 32 Switch Global Control Register 2 (0x04): SGCR2...............................................................................................67
Bank 32 Switch Global Control Register 3 (0x06): SGCR3...............................................................................................68
Bank 32 Switch Global Control Register 4 (0x08): SGCR4...............................................................................................69
Bank 32 Switch Global Control Register 5 (0x0A): SGCR5 ..............................................................................................69
Bank 33 Switch Global Control Register 6 (0x00): SGCR6...............................................................................................70
Bank 33 Switch Global Control Register 7 (0x02): SGCR7...............................................................................................70
Banks 34 – 38: Reserved..................................................................................................................................................70
Bank 39 MAC Address Register 1 (0x00): MACAR1 ........................................................................................................71
Bank 39 MAC Address Register 2 (0x02): MACAR2 ........................................................................................................71
Bank 39 MAC Address Register 3 (0x04): MACAR3 ........................................................................................................71
Bank 40 TOS Priority Control Register 1 (0x00): TOSR1 .................................................................................................71
Bank 40 TOS Priority Control Register 2 (0x02): TOSR2 .................................................................................................72
Bank 40 TOS Priority Control Register 3 (0x04): TOSR3 .................................................................................................72
Bank 40 TOS Priority Control Register 4 (0x06): TOSR4 .................................................................................................73
Bank 40 TOS Priority Control Register 5 (0x08): TOSR5 .................................................................................................73
Bank 40 TOS Priority Control Register 6 (0x0A): TOSR6 .................................................................................................74
Bank 41 TOS Priority Control Register 7 (0x00): TOSR7 .................................................................................................74
Bank 41 TOS Priority Control Register 8 (0x02): TOSR8 .................................................................................................75
Bank 42 Indirect Access Control Register (0x00): IACR ...................................................................................................75
Bank 42 Indirect Access Data Register 1 (0x02): IADR1 ..................................................................................................75
Bank 42 Indirect Access Data Register 2 (0x04): IADR2 ..................................................................................................76
Bank 42 Indirect Access Data Register 3 (0x06): IADR3 ..................................................................................................76
Bank 42 Indirect Access Data Register 4 (0x08): IADR4 ..................................................................................................76
Bank 42 Indirect Access Data Register 5 (0x0A): IADR5..................................................................................................76
Bank 43: Reserved ...........................................................................................................................................................76
Bank 44 Digital Testing Status Register (0x00): DTSR....................................................................................................76
Bank 44 Analog Testing Status Register (0x02): ATSR...................................................................................................76
Bank 44 Digital Testing Control Register (0x04): DTCR ..................................................................................................77
Bank 44 Analog Testing Control Register 0 (0x06): ATCR0 .............................................................................................77
Bank 44 Analog Testing Control Register 1 (0x08): ATCR1 .............................................................................................77
Bank 44 Analog Testing Control Register 2 (0x0A): ATCR2.............................................................................................77
Bank 45 PHY 1 MII-Register Basic Control Register (0x00): P1MBCR ............................................................................77
Bank 45 PHY 1 MII-Register Basic Status Register (0x02): P1MBSR ..............................................................................78
Bank 45 PHY 1 PHYID Low Register (0x04): PHY1ILR....................................................................................................79
Bank 45 PHY 1 PHYID High Register (0x06): PHY1IHR ..................................................................................................79
Bank 45 PHY 1 Auto-Negotiation Advertisement Register (0x08): P1ANAR ....................................................................79
Bank 45 PHY 1 Auto-Negotiation Link Partner Ability Register (0x0A): P1ANLPR ...........................................................80
Bank 46 PHY 2 MII-Register Basic Control Register (0x00): P2MBCR ............................................................................80
Bank 46 PHY 2 MII-Register Basic Status Register (0x02): P2MBSR ..............................................................................81
Bank 46 PHY 2 PHYID Low Register (0x04): PHY2ILR....................................................................................................82
Bank 46 PHY 2 PHYID High Register (0x06): PHY2IHR ..................................................................................................82
Bank 46 PHY 2 Auto-Negotiation Advertisement Register (0x08): P2ANAR ....................................................................83
Bank 46 PHY 2 Auto-Negotiation Link Partner Ability Register (0x0A): P2ANLPR ...........................................................83
Bank 47 PHY1 LinkMD Control/Status (0x00): P1VCT .....................................................................................................84
Bank 47 PHY1 Special Control/Status Register (0x02): P1PHYCTRL..............................................................................84
Bank 47 PHY2 LinkMD Control/Status (0x04): P2VCT .....................................................................................................85
Bank 47 PHY2 Special Control/Status Register (0x06): P2PHYCTRL..............................................................................85
Bank 48 Port 1 Control Register 1 (0x00): P1CR1............................................................................................................86
Bank 48 Port 1 Control Register 2 (0x02): P1CR2............................................................................................................87
Bank 48 Port 1 VID Control Register (0x04): P1VIDCR....................................................................................................88
Bank 48 Port 1 Control Register 3 (0x06): P1CR3............................................................................................................88
Bank 48 Port 1 Ingress Rate Control Register (0x08): P1IRCR........................................................................................89
Bank 48 Port 1 Egress Rate Control Register (0x0A): P1ERCR.......................................................................................91
Bank 49 Port 1 PHY Special Control/Status, LinkMD (0x00): P1SCSLMD .......................................................................93
Bank 49 Port 1 Control Register 4 (0x02): P1CR4............................................................................................................94
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Bank 49 Port 1 Status Register (0x04): P1SR ..................................................................................................................95
Bank 50 Port 2 Control Register 1 (0x00): P2CR1............................................................................................................96
Bank 50 Port 2 Control Register 2 (0x02): P2CR2............................................................................................................96
Bank 50 Port 2 VID Control Register (0x04): P2VIDCR....................................................................................................96
Bank 50 Port 2 Control Register 3 (0x06): P2CR3............................................................................................................96
Bank 50 Port 2 Ingress Rate Control Register (0x08): P2IRCR........................................................................................96
Bank 50 Port 2 Egress Rate Control Register (0x0A): P2ERCR.......................................................................................96
Bank 51 Port 2 PHY Special Control/Status, LinkMD (0x00): P2SCSLMD .......................................................................97
Bank 51 Port 2 Control Register 4 (0x02): P2CR4............................................................................................................98
Bank 51 Port 2 Status Register (0x04): P2SR ..................................................................................................................99
Bank 52 Host Port Control Register 1 (0x00): P3CR1 ....................................................................................................100
Bank 52 Host Port Control Register 2 (0x02): P3CR2 ....................................................................................................100
Bank 52 Host Port VID Control Register (0x04): P3VIDCR ............................................................................................101
Bank 52 Host Port Control Register 3 (0x06): P3CR3 ....................................................................................................101
Bank 52 Host Port Ingress Rate Control Register (0x08): P3IRCR ................................................................................101
Bank 52 Host Port Egress Rate Control Register (0x0A): P3ERCR ...............................................................................101
Banks 53 – 63: Reserved................................................................................................................................................101
MIB (Management Information Base) Counters ................................................................ 102
Format of “All Port Dropped Packet” MIB Counters ........................................................................................................103
Additional MIB Information..............................................................................................................................................104
Static MAC Address Table .................................................................................................. 105
Static MAC Table Lookup Examples:..............................................................................................................................105
Dynamic MAC Address Table ............................................................................................. 106
Dynamic MAC Address Lookup Example: ......................................................................................................................106
VLAN Table........................................................................................................................... 107
VLAN Table Lookup Examples: ......................................................................................................................................107
Absolute Maximum Ratings(1) ............................................................................................. 108
Operating Ratings(1) ............................................................................................................. 108
Electrical Characteristics(1) ................................................................................................. 109
Timing Specifications .......................................................................................................... 110
Asynchronous Timing without using Address Strobe (ADSN = 0)...................................................................................110
Asynchronous Timing using Address Strobe (ADSN) .....................................................................................................111
Asynchronous Timing using DATACSN..........................................................................................................................112
Address Latching Timing for All Modes...........................................................................................................................113
Synchronous Timing in Burst Write (VLBUSN = 1) .........................................................................................................114
Synchronous Timing in Burst Read (VLBUSN = 1).........................................................................................................115
Synchronous Write Timing (VLBUSN = 0) ......................................................................................................................116
Synchronous Read Timing (VLBUSN = 0) ......................................................................................................................117
EEPROM Timing.............................................................................................................................................................118
Auto Negotiation Timing..................................................................................................................................................119
Reset Timing...................................................................................................................................................................120
Selection of Isolation Transformers................................................................................... 121
Selection of Reference Crystal ........................................................................................... 121
Package Information............................................................................................................ 122
Acronyms and Glossary...................................................................................................... 124
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List of Figures
Figure 1. KSZ8842M Functional Diagram ..................................................................................................................................... 1
Figure 2. Standard – KSZ8842-16 MQL 128-Pin PQFP (Top View)............................................................................................ 10
Figure 3. Option – KSZ8842-16 MVL 128-Pin LQFP (Top View) ................................................................................................ 10
Figure 4. Standard – KSZ8842-32 MQL 128-Pin PQFP (Top View)............................................................................................ 16
Figure 5. Option – KSZ8842-32 MVL 128-Pin LQFP (Top View) ................................................................................................ 16
Figure 6. Typical Straight Cable Connection ............................................................................................................................... 23
Figure 7. Typical Crossover Cable Connection ........................................................................................................................... 24
Figure 8. Auto Negotiation and Parallel Operation ...................................................................................................................... 25
Figure 9. Destination Address Lookup Flow Chart in Stage One ................................................................................................ 27
Figure 10. Destination Address Resolution Flow Chart in Stage Two ......................................................................................... 28
Figure 11. Mapping from ISA-like, EISA-like, and VLBus-like transactions to the KSZ8842M Bus ............................................. 34
Figure 12. KSZ8842M 8-Bit, 16-Bit, and 32-Bit Data Bus Connections ....................................................................................... 34
Figure 13. 802.1p Priority Field Format ....................................................................................................................................... 41
Figure 14. Port 2 Far-End Loopback Path ................................................................................................................................... 44
Figure 15. Port 1 and port 2 Near-End (Remote) Loopback Path................................................................................................ 44
Figure 16. Asynchronous Cycle – ADSN = 0............................................................................................................................. 110
Figure 17. Asynchronous Cycle – Using ADSN......................................................................................................................... 111
Figure 18. Asynchronous Cycle – Using DATACSN ................................................................................................................. 112
Figure 19. Address Latching Cycle for All Modes...................................................................................................................... 113
Figure 20. Synchronous Burst Write Cycles – VLBUSN = 1...................................................................................................... 114
Figure 21. Synchronous Burst Read Cycles – VLBUSN = 1 ..................................................................................................... 115
Figure 22. Synchronous Write Cycle – VLBUSN = 0................................................................................................................. 116
Figure 23. Synchronous Read Cycle – VLBUSN = 0................................................................................................................. 117
Figure 24. EEPROM Read Cycle Timing Diagram .................................................................................................................... 118
Figure 25. Auto-Negotiation Timing........................................................................................................................................... 119
Figure 26. Reset Timing ............................................................................................................................................................ 120
Figure 27. 128-Pin PQFP Package ........................................................................................................................................... 122
Figure 28. Optional 128-Pin LQFP Package ............................................................................................................................. 123
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List of Tables
Table 1. MDI/MDI-X Pin Definitions ............................................................................................................................................. 23
Table 2. Bus Interface Unit Signal Grouping ............................................................................................................................... 32
Table 3: Transmit Queue Frame Format ..................................................................................................................................... 35
Table 4. Transmit Control Word Bit Fields................................................................................................................................... 36
Table 5. Transmit Byte Count Format ......................................................................................................................................... 36
Table 6: Receive Queue Frame Format ...................................................................................................................................... 36
Table 7. FRXQ Packet Receive Status........................................................................................................................................ 37
Table 8. FRXQ RX Byte Count Field ........................................................................................................................................... 37
Table 9: Spanning Tree States.................................................................................................................................................... 38
Table 10. FID+DA Lookup in VLAN Mode................................................................................................................................... 40
Table 11. FID+SA Lookup in VLAN Mode ................................................................................................................................... 40
Table 12. EEPROM Format......................................................................................................................................................... 42
Table 13. ConfigParam Word in EEPROM Format ..................................................................................................................... 43
Table 14. Format of Per Port MIB Counters .............................................................................................................................. 102
Table 15. Port 1 MIB Counters Indirect Memory Offset ............................................................................................................. 103
Table 16. “All Port Dropped Packet” MIB Counters Format....................................................................................................... 103
Table 17. “All Port Dropped Packet” MIB Counters Indirect Memory Offsets ............................................................................ 103
Table 18. Static MAC Table Format .......................................................................................................................................... 105
Table 19. Dynamic MAC Address Table Format ....................................................................................................................... 106
Table 20. VLAN Table Format................................................................................................................................................... 107
Table 21. Maximum Ratings...................................................................................................................................................... 108
Table 22. Operating Ratings...................................................................................................................................................... 108
Table 23. Electrical Characteristics ........................................................................................................................................... 109
Table 24. Asynchronous Cycle – ADSN = 0 Timing Parameters............................................................................................... 110
Table 25. Asynchronous Cycle – ADSN Timing Parameters..................................................................................................... 111
Table 26. Asynchronous – DATACSN Timing Parameters........................................................................................................ 112
Table 27. Address Latching Timing Parameters........................................................................................................................ 113
Table 28. Synchronous Burst Write Timing Parameters............................................................................................................ 114
Table 29. Synchronous Burst Read Timing Parameters............................................................................................................ 115
Table 30. Synchronous Write Timing Parameters ..................................................................................................................... 116
Table 31. Synchronous Read Timing Parameters..................................................................................................................... 117
Table 32. EEPROM Timing Parameters.................................................................................................................................... 118
Table 33. Auto Negotiation Timing Parameters......................................................................................................................... 119
Table 34. Reset Timing Parameters .......................................................................................................................................... 120
Table 35. Transformer Selection Criteria................................................................................................................................... 121
Table 36. Qualified Single Port Magnetic .................................................................................................................................. 121
Table 37. Typical Reference Crystal Characteristics ................................................................................................................. 121
November 2005
9
Rev. 1.4
Micrel Confidential
KSZ8842-16/32 MQL/MVL
1 03
1 04
1 05
1 06
1 07
1 08
1 09
1 10
1 11
1 12
1 13
1 14
1 15
1 16
1 17
1 18
1 19
1 20
1 21
1 22
1 23
1 24
1 25
1 26
1 27
128
K S Z 8 8 4 2 -1 6
MQL
(T o p V ie w )
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
AGND
VDDAP
AGND
IS E T
NC
NC
AGND
VDDA
TXP2
TXM 2
AGND
RXP2
RXM 2
VDDARX
VDDATX
TXM 1
TXP1
AGND
RXM 1
RXP1
NC
VDDA
AGND
NC
NC
AGND
TESTEN
SCANEN
P1LED2
P1LED1
P1LED0
P2LED2
P2LED1
P2LED0
DGND
VDDIO
RDYRTNN
BCLK
NC
NC
SRDYN
INTRN
LDEVN
RDN
EECS
ARDY
CYCLEN
P2LED3
DGND
VDDCO
VLBUSN
EEEN
P1LED3
EEDO
EESK
EEDI
SWR
AEN
WRN
DGND
ADSN
PWRDN
AGND
VDDA
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
NC
NC
NC
NC
DGND
V D D IO
NC
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
DGND
DGND
V D D IO
D2
D1
D0
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
VDDIO
VDDC
DGND
NC
BE0N
BE1N
NC
NC
A1
A2
A3
A4
A5
VDDIO
DGND
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
RSTN
X2
X1
Pin Configuration for KSZ8842-16 Switches (8/16-Bit)
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
NC
NC
NC
NC
VDDIO
VDDC
DGND
NC
BE0N
BE1N
NC
NC
A1
A2
A3
A4
A5
VDDIO
DGND
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
RSTN
X2
X1
Figure 2. Standard – KSZ8842-16 MQL 128-Pin PQFP (Top View)
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
K SZ8842-16
M VL
(Top V iew )
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
AG N D
VD D A P
AG N D
IS ET
NC
NC
AG N D
VD D A
TXP 2
TXM 2
AG N D
R XP 2
R XM 2
VD D A R X
VD D A TX
TXM 1
TXP 1
AG N D
R XM 1
R XP 1
NC
VD D A
AG N D
NC
NC
AG N D
VDDA
AG N D
PWRDN
A D SN
DGND
W RN
TESTEN
SCANEN
P1LED2
P1LED1
P1LED0
P2LED2
P2LED1
P2LED0
DGND
VDDIO
RDYRTNN
BCLK
NC
NC
SRDYN
INTRN
LDEVN
RDN
EECS
ARDY
CYCLEN
P2LED3
DGND
VDDCO
VLBUSN
EEEN
P1LED3
EEDO
EESK
EEDI
SWR
AEN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
DGND
VD D IO
NC
D 15
D 14
D 13
D 12
D 11
D 10
D9
D8
D7
D6
D5
D4
D3
DGND
DGND
VD D IO
D2
D1
D0
Figure 3. Option – KSZ8842-16 MVL 128-Pin LQFP (Top View)
November 2005
10
Rev. 1.4
Micrel Confidential
KSZ8842-16/32 MQL/MVL
Pin Description for KSZ8842-16 Switches (8/16-Bit)
Pin
Number
Pin Name
Type
Pin Function
1
TEST_EN
I
Test Enable
For normal operation, pull-down this pin to ground.
2
SCAN_EN
I
Scan Test Scan Mux Enable
For normal operation, pull-down this pin to ground.
3
P1LED2
Opu
4
P1LED1
Opu
5
P1LED0
Opu
1
Port 1 and Port 2 LED indicators defined as follows:
Switch Global Control Register 5:
SGCR5 bit [15,9]
[0,0] Default
2
[0,1]
P1LED3 /P2LED3
—
—
P1LED2/P2LED2
Link/Act
100Link/Act
P1LED1/P2LED1
Full duplex/Col
10Link/Act
P1LED0/P2LED0
Speed
Full duplex
Reg. SGCR5 bit [15,9]
[1,0]
6
P2LED2
Opu
7
P2LED1
Opu
8
P2LED0
Opu
[1,1]
2
P1LED3 /P2LED3
Act
—
P1LED2/P2LED2
Link
—
P1LED1/P2LED1
Full duplex/Col
—
P1LED0/P2LED0
Speed
—
Notes:
1. Link = On; Activity = Blink; Link/Act = On/Blink; Full Dup/Col = On/Blink;
Full Duplex = On (Full duplex); Off (Half duplex)
Speed = On (100BASE-T); Off (10BASE-T)
2. P1LED3 is pin 27. P2LED3 is pin 22.
3
Port 1 and Port 2 LED indicators for Repeater mode defined as follows:
Switch Global Control Register 5: SGCR5 bit
[15,9]
[0,0] Default
[0,1] [1,0] [1,1]
P1LED3, P2LED3
RPT_COL, RPT_ACT
—
P1LED2, P2LED2
RPT_Link3/RX, RPT_ERR3
—
P1LED1, P2LED1
RPT_Link2/RX, RPT_ERR2
—
P1LED0, P2LED0
RPT_Link1/RX, RPT_ERR1
—
Note 3: RPT_COL = Blink; RPT_Link3/RX (Host port) = On/Blink;
RPT_Link2/RX (Port 2) = On/Blink; RPT_Link1/RX (Port 1) = On/Blink;
RPT_ACT = on if any activity, RPT_ERR3/2/1 = RX error on port 3, 2, or 1.
9
DGND
Gnd
Digital ground
10
VDDIO
P
3.3V digital VDDIO input power supply for IO with well decoupling capacitors.
11
RDYRTNN
Ipd
Ready Return Not:
For VLBus-like mode: Asserted by the host to complete synchronous read cycles. If
the host doesn’t connect to this pin, assert this pin.
For burst mode (32-bit interface only): Host drives this pin low to signal waiting
states.
November 2005
11
Rev. 1.4
Micrel Confidential
KSZ8842-16/32 MQL/MVL
Pin
Number
Pin Name
Type
Pin Function
12
BCLK
Ipd
Bus Interface Clock
Local bus clock for synchronous bus systems. Maximum frequency is 50MHz.
This pin should be tied Low or unconnected if it is in asynchronous mode.
13
NC
Ipu
No connect.
14
NC
Opu
No connect.
15
SRDYN
Opu
Synchronous Ready Not
Ready signal to interface with synchronous bus for both EISA-like and VLBus-like
extend accesses.
For VLBus-like mode, the falling edge of this signal indicates ready. This signal is
synchronous to the bus clock signal BCLK.
For burst mode (32-bit interface only), the KSZ8842M drives this pin low to signal
wait states.
16
INTRN
Opd
Interrupt
Active Low signal to host CPU to indicate an interrupt status bit is set, this pin need
an external 4.7K pull-up resistor.
17
LDEVN
Opd
Local Device Not
Active Low output signal, asserted when AEN is Low and A15-A4 decode to the
KSZ8842M address programmed into the high byte of the base address register.
LDEVN is a combinational decode of the Address and AEN signal.
18
RDN
Ipd
Read Strobe Not
Asynchronous read strobe, active Low.
19
EECS
Opu
EEPROM Chip Select
20
ARDY
Opd
Asynchronous Ready
ARDY may be used when interfacing asynchronous buses to extend bus access
cycles. It is asynchronous to the host CPU or bus clock.
21
CYCLEN
Ipd
Cycle Not
For VLBus-like mode cycle signal; this pin follows the addressing cycle to signal the
command cycle.
For burst mode (32-bit interface only), this pin stays High for read cycles and Low for
write cycles.
22
P2LED3
Opd
Port 2 LED indicator
See the description in pins 6, 7, and 8.
23
DGND
Gnd
Digital IO ground
24
VDDCO
P
1.2V digital core voltage output (internal 1.2V LDO power supply output), this 1.2V
output pin provides power to VDDC, VDDA and VDDAP pins.
Note: Internally generated power voltage. Do not connect an external power supply to
this pin. This pin is used for connecting external filter (Ferrite bead and capacitors).
25
VLBUSN
Ipd
VLBus-like Mode
Pull-down or float: Bus interface is configured for synchronous mode.
Pull-up: Bus interface is configured for 8-bit or 16-bit asynchronous mode or EISAlike burst mode.
26
EEEN
Ipd
EEPROM Enable
EEPROM is enabled and connected when this pin is pull-up.
EEPROM is disabled when this pin is pull-down or no connect.
27
P1LED3
Opd
Port 1 LED indicator
See the description in pins 3, 4, and 5.
November 2005
12
Rev. 1.4
Micrel Confidential
KSZ8842-16/32 MQL/MVL
Pin
Number
Pin Name
Type
Pin Function
28
EEDO
Opd
EEPROM Data Out
This pin is connected to DI input of the serial EEPROM.
29
EESK
Opd
EEPROM Serial Clock
A 4µs serial output clock to load configuration data from the serial EEPROM.
30
EEDI
Ipd
EEPROM Data In
This pin is connected to DO output of the serial EEPROM when EEEN is pull-up.
This pin can be pull-down for 8-bit bus mode, pull-up for 16-bus mode or don’t care
for 32-bus mode when EEEN is pull-down (without EEPROM).
31
SWR
Ipd
Synchronous Write/Read
Write/Read signal for synchronous bus accesses. Write cycles when high and Read
cycles when low.
32
AEN
Ipd
Address Enable
Address qualifier for the address decoding, active Low.
33
WRN
Ipd
Write Strobe Not
Asynchronous write strobe, active Low.
34
DGND
Gnd
Digital IO ground
35
ADSN
Ipd
Address Strobe Not
For systems that require address latching, the rising edge of ADSN indicates the
latching moment of A15-A1 and AEN.
36
PWRDN
I
Full-chip power-down. Active Low (Low = Power down; High = Normal operation).
37
AGND
Gnd
Analog ground
38
VDDA
P
1.2V analog VDD input power supply from VDDCO (pin24) through external Ferrite
bead and capacitor.
39
AGND
Gnd
Analog ground
40
NC
—
No connect
41
NC
—
No connect
42
AGND
Gnd
Analog ground
43
VDDA
P
1.2V analog VDD input power supply from VDDCO (pin24) through external Ferrite
bead and capacitor.
44
NC
—
No connect
45
RXP1
I/O
Port 1 physical receive (MDI) or transmit (MDIX) signal (+ differential)
46
RXM1
I/O
Port 1 physical receive (MDI) or transmit (MDIX) signal (– differential)
47
AGND
Gnd
Analog ground
48
TXP1
I/O
Port 1 physical transmit (MDI) or receive (MDIX) signal (+ differential)
49
TXM1
I/O
Port 1 physical transmit (MDI) or receive (MDIX) signal (– differential)
50
VDDATX
P
3.3V analog VDD input power supply with well decoupling capacitors.
51
VDDARX
P
3.3V analog VDD input power supply with well decoupling capacitors.
52
RXM2
I/O
Port 2 physical receive (MDI) or transmit (MDIX) signal (- differential)
53
RXP2
I/O
Port 2 physical receive (MDI)or transmit (MDIX) signal (+ differential)
54
AGND
Gnd
Analog ground
55
TXM2
I/O
Port 2 physical receive (MDI) or transmit (MDIX) signal (- differential)
56
TXP2
I/O
Port 2 physical receive (MDI) or transmit (MDIX) signal (+ differential)
57
VDDA
P
1.2 analog VDD input power supply from VDDCO (pin24) through external Ferrite
November 2005
13
Rev. 1.4
Micrel Confidential
KSZ8842-16/32 MQL/MVL
Pin
Number
Pin Name
Type
Pin Function
58
AGND
Gnd
Analog ground
59
NC
Ipu
No connect
60
NC
Ipu
No connect
61
ISET
O
Set physical transmits output current.
bead and capacitor.
Pull-down this pin with a 3.01K 1% resistor to ground.
62
AGND
Gnd
Analog ground
63
VDDAP
P
1.2V analog VDD for PLL input power supply from VDDCO (pin24) through external
Ferrite bead and capacitor.
64
AGND
Gnd
Analog ground
65
X1
I
25MHz crystal or oscillator clock connection.
66
X2
O
Pins (X1, X2) connect to a crystal. If an oscillator is used, X1 connects to a 3.3V
tolerant oscillator and X2 is a no connect.
Note: Clock requirement is ± 50ppm for either crystal or oscillator.
67
RSTN
Ipu
Hardware reset pin (active Low). This reset input is required minimum of 10ms low
after stable supply voltage 3.3V.
68
A15
I
Address 15
69
A14
I
Address 14
70
A13
I
Address 13
71
A12
I
Address 12
72
A11
I
Address 11
73
A10
I
Address 10
74
A9
I
Address 9
75
A8
I
Address 8
76
A7
I
Address 7
77
A6
I
Address 6
78
DGND
Gnd
Digital IO ground
79
VDDIO
P
3.3V digital VDDIO input power supply for IO with well decoupling capacitors.
80
A5
I
Address 5
81
A4
I
Address 4
82
A3
I
Address 3
83
A2
I
Address 2
84
A1
I
Address 1
85
NC
I
No Connect
86
NC
I
No Connect
87
BE1N
I
Byte Enable 1 Not, Active low for Data byte 1 enable (don’t care in 8-bit bus mode).
88
BE0N
I
Byte Enable 0 Not, Active low for Data byte 0 enable (there is an internal inverter
enabled and connected to the BE1N for 8-bit bus mode).
89
NC
I
No Connect
90
DGND
Gnd
Digital core ground
91
VDDC
P
1.2V digital core VDD input power supply from VDDCO (pin24) through external
Ferrite bead and capacitor.
92
VDDIO
P
3.3V digital VDDIO input power supply for IO with well decoupling capacitors.
93
NC
I
No Connect
November 2005
14
Rev. 1.4
Micrel Confidential
KSZ8842-16/32 MQL/MVL
Pin
Number
Pin Name
Type
Pin Function
94
NC
I
No Connect
95
NC
I
No Connect
96
NC
I
No Connect
97
NC
I
No Connect
98
NC
I
No Connect
99
NC
I
No Connect
100
NC
I
No Connect
101
NC
I
No Connect
102
NC
I
No Connect
103
NC
I
No Connect
104
NC
I
No Connect
105
NC
I
No Connect
106
NC
I
No Connect
107
DGND
Gnd
Digital IO ground
108
VDDIO
P
3.3V digital VDDIO input power supply for IO with well decoupling capacitors.
109
NC
I
No Connect
110
D15
I/O
Data 15
111
D14
I/O
Data 14
112
D13
I/O
Data 13
113
D12
I/O
Data 12
114
D11
I/O
Data 11
115
D10
I/O
Data 10
116
D9
I/O
Data 9
117
D8
I/O
Data 8
118
D7
I/O
Data 7
119
D6
I/O
Data 6
120
D5
I/O
Data 5
121
D4
I/O
Data 4
122
D3
I/O
Data 3
123
DGND
Gnd
Digital IO ground
124
DGND
Gnd
Digital core ground
125
VDDIO
P
3.3V digital VDDIO input power supply for IO with well decoupling capacitors.
126
D2
I/O
Data 2
127
D1
I/O
Data 1
128
D0
I/O
Data 0
Legend:
P = Power supply
Gnd = Ground.
I/O = Bi-directional
I = Input O = Output.
Ipd = Input with internal pull-down.
Ipu = Input with internal pull-up.
Opd = Output with internal pull-down.
Opu = Output with internal pull-up.
November 2005
15
Rev. 1.4
Micrel Confidential
KSZ8842-16/32 MQL/MVL
1 03
1 04
1 05
1 06
1 07
1 08
1 09
1 10
1 11
1 12
1 13
1 14
1 15
1 16
1 17
1 18
1 19
1 20
1 21
1 22
1 23
1 24
1 25
1 26
1 27
12 8
K S Z 8842-32
MQL
(T o p V iew )
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
AGND
VDDAP
AGND
IS E T
NC
NC
AGND
VDDA
TX P 2
TX M 2
AGND
RXP2
RXM2
VDDARX
VDDATX
TX M 1
TX P 1
AGND
RXM1
RXP1
NC
VDDA
AGND
NC
NC
AGND
TESTEN
SCANEN
P1LED2
P1LED1
P1LED0
P2LED2
P2LED1
P2LED0
DGND
VDDIO
RDYRTNN
BCLK
DATACSN
NC
SRDYN
INTRN
LDEVN
RDN
EECS
ARDY
CYCLEN
P2LED3
DGND
VDDCO
VLBUSN
EEEN
P1LED3
EEDO
EESK
EEDI
SWR
AEN
WRN
DGND
ADSN
PWRDN
AGND
VDDA
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
D20
D19
D18
D17
DGND
V D D IO
D16
D15
D 14
D13
D12
D 11
D10
D9
D8
D7
D6
D5
D4
D3
DGND
DGND
V D D IO
D2
D1
D0
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
D21
D22
D23
D24
D25
D26
D27
D28
D29
D30
VDDIO
VDDC
DGND
D31
BE0N
BE1N
BE2N
BE3N
A1
A2
A3
A4
A5
VDDIO
DGND
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
RSTN
X2
X1
Pin Configuration for KSZ8842-32 Switches (32-Bit)
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
D27
D28
D29
D30
VDDIO
VDDC
DGND
D31
BE0N
BE1N
BE2N
BE3N
A1
A2
A3
A4
A5
VDDIO
DGND
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
RSTN
X2
X1
Figure 4. Standard – KSZ8842-32 MQL 128-Pin PQFP (Top View)
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
KSZ8842-32
MVL
(Top View)
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
AGND
VDDAP
AGND
ISET
NC
NC
AGND
VDDA
TXP2
TXM2
AGND
RXP2
RXM2
VDDARX
VDDATX
TXM1
TXP1
AGND
RXM1
RXP1
NC
VDDA
AGND
NC
NC
AGND
VDDA
AGND
PW RDN
ADSN
DG ND
W RN
TESTEN
SCANEN
P1LED2
P1LED1
P1LED0
P2LED2
P2LED1
P2LED0
DGND
VDDIO
RDYRTNN
BCLK
DATACSN
NC
SRDYN
INTRN
LDEVN
RDN
EECS
ARDY
CYCLEN
P2LED3
DGND
VDDCO
VLBUSN
EEEN
P1LED3
EEDO
EESK
EEDI
SWR
AEN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
D26
D25
D24
D23
D22
D21
D20
D19
D18
D17
DGND
VDDIO
D16
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
DGND
DGND
VDDIO
D2
D1
D0
Figure 5. Option – KSZ8842-32 MVL 128-Pin LQFP (Top View)
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Pin Description for KSZ8842-32 Switches (32-Bit)
Pin
Number
Pin Name
Type
Pin Function
1
TEST_EN
I
Test Enable
For normal operation, pull-down this pin to ground.
2
SCAN_EN
I
Scan Test Scan Mux Enable
For normal operation, pull-down this pin to ground.
3
P1LED2
Opu
4
P1LED1
Opu
5
P1LED0
Opu
1
Port 1 and Port 2 LED indicators defined as follows:
Switch Global Control Register 5:
SGCR5 bit [15,9]
[0,0] Default
2
[0,1]
P1LED3 /P2LED3
—
—
P1LED2/P2LED2
Link/Act
100Link/Act
P1LED1/P2LED1
Full duplex/Col
10Link/Act
P1LED0/P2LED0
Speed
Full duplex
Reg. SGCR5 bit [15,9]
[1,0]
6
P2LED2
Opu
7
P2LED1
Opu
8
P2LED0
Opu
[1,1]
2
P1LED3 /P2LED3
Act
—
P1LED2/P2LED2
Link
—
P1LED1/P2LED1
Full duplex/Col
—
P1LED0/P2LED0
Speed
—
Notes:
1. Link = On; Activity = Blink; Link/Act = On/Blink; Full Dup/Col = On/Blink;
Full Duplex = On (Full duplex); Off (Half duplex)
Speed = On (100BASE-T); Off (10BASE-T)
2. P1LED3 is pin 27. P2LED3 is pin 22.
3
Port 1 and Port 2 LED indicators for Repeater mode defined as follows:
Switch Global Control Register 5: SGCR5 bit
[15,9]
[0,0] Default
[0,1] [1,0] [1,1]
P1LED3; P2LED3
RPT_COL; RPT_ACT
—
P1LED2; P2LED2
RPT_Link3/RX; RPT_ERR3
—
P1LED1; P2LED1
RPT_Link2/RX; RPT_ERR2
—
P1LED0; P2LED0
RPT_Link1/RX; RPT_ERR1
—
Note 3: RPT_COL = Blink; RPT_Link3/RX (Host port) = On/Blink;
RPT_Link2/RX (Port 2) = On/Blink; RPT_Link1/RX (Port 1) = On/Blink;
RPT_ACT = on if any activity, RPT_ERR3/2/1 = RX error on port 3, 2, or 1.
9
DGND
Gnd
Digital ground
10
VDDIO
P
3.3V digital VDDIO input power supply for IO with well decoupling capacitors.
11
RDYRTNN
Ipd
Ready Return Not
For VLBus-like mode: Asserted by the host to complete synchronous read cycles. If
the host doesn’t connect to this pin, assert this pin.
For burst mode (32-bit interface only): Host drives this pin low to signal waiting
states.
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Pin
Number
Pin Name
Type
Pin Function
12
BCLK
Ipd
Bus Interface Clock
Local bus clock for synchronous bus systems. Maximum frequency is 50MHz.
This pin should be tied Low or unconnected if it is in asynchronous mode.
13
DATACSN
Ipu
DATA Chip Select Not (For KSZ8842-32 Mode only)
Chip select signal for QMU data register (QDRH, QDRL), active Low.
When DATACSN is Low, the data path can be accessed regardless of the value of
AEN, A15-A1, and the content of the BANK select register.
14
NC
Opu
No connect.
15
SRDYN
Opu
Synchronous Ready Not
Ready signal to interface with synchronous bus for both EISA-like and VLBus-like
extend accesses.
For VLBus-like mode, the falling edge of this signal indicates ready. This signal is
synchronous to the bus clock signal BCLK.
For burst mode (32-bit interface only), the KSZ8842M drives this pin low to signal
wait states.
16
INTRN
Opd
Interrupt
Active Low signal to host CPU to indicate an interrupt status bit is set, this pin need
an external 4.7K pull-up resistor.
17
LDEVN
Opd
Local Device Not
Active Low output signal, asserted when AEN is Low and A15-A4 decode to the
KSZ8842M address programmed into the high byte of the base address register.
LDEVN is a combinational decode of the Address and AEN signal.
18
RDN
Ipd
Read Strobe Not
Asynchronous read strobe, active Low.
19
EECS
Opu
EEPROM Chip Select
20
ARDY
Opd
Asynchronous Ready
ARDY may be used when interfacing asynchronous buses to extend bus access
cycles. It is asynchronous to the host CPU or bus clock.
21
CYCLEN
Ipd
Cycle Not
For VLBus-like mode cycle signal; this pin follows the addressing cycle to signal the
command cycle.
For burst mode (32-bit interface only), this pin stays High for read cycles and Low for
write cycles.
22
P2LED3
Opd
Port 2 LED indicator.
See the description in pins 6, 7, and 8.
23
DGND
Gnd
Digital IO ground
24
VDDCO
P
1.2V digital core voltage output (internal 1.2V LDO power supply output), this 1.2V
output pin provides power to VDDC, VDDA and VDDAP pins.
Note: Internally generated power voltage. Do not connect an external power supply to
this pin. This pin is used for connecting external filter (Ferrite Bead and capacitors).
25
VLBUSN
Ipd
VLBus-like Mode
Pull-down or float: Bus interface is configured for synchronous mode.
Pull-up: Bus interface is configured for 32-bit asynchronous mode or EISA-like burst
mode.
26
EEEN
Ipd
EEPROM Enable
EEPROM is enabled and connected when this pin is pull-up.
EEPROM is disabled when this pin is pull-down or no connect.
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Pin
Number
Pin Name
Type
Pin Function
27
P1LED3
Opd
Port 1 LED indicator
See the description in pins 3, 4, and 5.
28
EEDO
Opd
EEPROM Data Out
This pin is connected to DI input of the serial EEPROM.
29
EESK
Opd
EEPROM Serial Clock
A 4µs serial output clock to load configuration data from the serial EEPROM.
30
EEDI
Ipd
EEPROM Data In
This pin is connected to DO output of the serial EEPROM when EEEN is pull-up.
This pin can be pull-down for 8-bit bus mode, pull-up for 16-bus mode or don’t care
for 32-bus mode when EEEN is pull-down (without EEPROM).
31
SWR
Ipd
Synchronous Write/Read
Write/Read signal for synchronous bus accesses. Write cycles when high and Read
cycles when low.
32
AEN
Ipd
Address Enable
Address qualifier for the address decoding, active Low.
33
WRN
Ipd
Write Strobe Not
Asynchronous write strobe, active Low.
34
DGND
Gnd
Digital IO ground
35
ADSN
Ipd
Address Strobe Not
For systems that require address latching, the rising edge of ADSN indicates the
latching moment of A15-A1 and AEN.
36
PWRDN
I
Full-chip power-down. Active Low (Low = Power down; High = Normal operation).
37
AGND
Gnd
Analog ground
38
VDDA
P
1.2V analog VDD input power supply from VDDCO (pin24) through external Ferrite
bead and capacitor.
39
AGND
Gnd
Analog ground
40
NC
—
No connect
41
NC
—
No connect
42
AGND
Gnd
Analog ground
43
VDDA
P
1.2V analog VDD input power supply from VDDCO (pin24) through external Ferrite
bead and capacitor.
44
NC
—
No connect
45
RXP1
I/O
Port 1 physical receive (MDI) or transmit (MDIX) signal (+ differential)
46
RXM1
I/O
Port 1 physical receive (MDI) or transmit (MDIX) signal (– differential)
47
AGND
Gnd
Analog ground
48
TXP1
I/O
Port 1 physical transmit (MDI) or receive (MDIX) signal (+ differential)
49
TXM1
I/O
Port 1 physical transmit (MDI) or receive (MDIX) signal (– differential)
50
VDDATX
P
3.3V analog VDD input power supply with well decoupling capacitors.
51
VDDARX
P
3.3V analog VDD
52
RXM2
I/O
Port 2 physical receive (MDI) or transmit (MDIX) signal (- differential)
53
RXP2
I/O
Port 2 physical receive (MDI) or transmit (MDIX) signal (+ differential)
54
AGND
Gnd
Analog ground
55
TXM2
I/O
Port 2 physical receive (MDI) or transmit (MDIX) signal (- differential)
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Pin
Number
Pin Name
Type
Pin Function
56
TXP2
I/O
Port 2 physical receive (MDI) or transmit (MDIX) signal (+ differential)
57
VDDA
P
1.2 analog VDD input power supply from VDDCO (pin24) through external Ferrite
bead and capacitor.
58
AGND
Gnd
Analog ground
59
NC
Ipu
No connect
60
NC
Ipu
No connect
61
ISET
O
Set physical transmits output current.
Pull-down this pin with a 3.01K 1% resistor to ground.
62
AGND
Gnd
Analog ground
63
VDDAP
P
1.2V analog VDD for PLL input power supply from VDDCO (pin24) through external
Ferrite bead and capacitor.
64
AGND
Gnd
Analog ground
65
X1
I
25MHz crystal or oscillator clock connection.
66
X2
O
Pins (X1, X2) connect to a crystal. If an oscillator is used, X1 connects to a 3.3V
tolerant oscillator and X2 is a no connect.
Note: Clock is ± 50ppm for either crystal or oscillator.
67
RSTN
Ipu
Hardware reset pin (active Low). This reset input is required minimum of 10ms low
after stable supply voltage 3.3V.
68
A15
I
Address 15
69
A14
I
Address 14
70
A13
I
Address 13
71
A12
I
Address 12
72
A11
I
Address 11
73
A10
I
Address 10
74
A9
I
Address 9
75
A8
I
Address 8
76
A7
I
Address 7
77
A6
I
Address 6
78
DGND
Gnd
Digital IO ground
79
VDDIO
P
3.3V digital VDDIO input power supply for IO with well decoupling capacitors.
80
A5
I
Address 5
81
A4
I
Address 4
82
A3
I
Address 3
83
A2
I
Address 2
84
A1
I
Address 1
85
BE3N
I
Byte Enable 3 Not, Active low for Data byte 3 enable.
86
BE2N
I
Byte Enable 2 Not, Active low for Data byte 2 enable.
87
BE1N
I
Byte Enable 1 Not, Active low for Data byte 1 enable.
88
BE0N
I
Byte Enable 0 Not, Active low for Data byte 0 enable.
89
D31
I/O
Data 31
90
DGND
Gnd
Digital core ground
91
VDDC
P
1.2V digital core VDD input power supply from VDDCO (pin24) through external
Ferrite bead and capacitor.
92
VDDIO
P
3.3V digital VDDIO input power supply for IO with well decoupling capacitors.
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Pin
Number
Pin Name
Type
Pin Function
93
D30
I/O
Data 30
94
D29
I/O
Data 29
95
D28
I/O
Data 28
96
D27
I/O
Data 27
97
D26
I/O
Data 26
98
D25
I/O
Data 25
99
D24
I/O
Data 24
100
D23
I/O
Data 23
101
D22
I/O
Data 22
102
D21
I/O
Data 21
103
D20
I/O
Data 20
104
D19
I/O
Data 19
105
D18
I/O
Data 18
106
D17
I/O
Data 17
107
DGND
Gnd
Digital IO ground
108
VDDIO
P
3.3V digital VDDIO input power supply for IO with well decoupling capacitors.
109
D16
I/O
Data 16
110
D15
I/O
Data 15
111
D14
I/O
Data 14
112
D13
I/O
Data 13
113
D12
I/O
Data 12
114
D11
I/O
Data 11
115
D10
I/O
Data 10
116
D9
I/O
Data 9
117
D8
I/O
Data 8
118
D7
I/O
Data 7
119
D6
I/O
Data 6
120
D5
I/O
Data 5
121
D4
I/O
Data 4
122
D3
I/O
Data 3
123
DGND
Gnd
Digital IO ground
124
DGND
Gnd
Digital core ground
125
VDDIO
P
3.3V digital VDDIO input power supply for IO with well decoupling capacitors.
126
D2
I/O
Data 2
127
D1
I/O
Data 1
128
D0
I/O
Data 0
Legend:
P = Power supply
Gnd = Ground.
I/O = Bi-directional
I = Input O = Output.
Ipd = Input with internal pull-down.
Ipu = Input with internal pull-up.
Opd = Output with internal pull-down.
Opu = Output with internal pull-up.
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Functional Description
The KSZ8842M contains two 10/100 physical layer transceivers (PHYs), two MAC units, and a DMA channel
integrated with a Layer-2 switch.
The KSZ8842M contains a bus interface unit (BIU), which controls the KSZ8842M via an 8, 16, or 32-bit host
interface.
Physical signal transmission and reception are enhanced through the use of analog circuits in the PHY that make
the design more efficient and allow for low power consumption.
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, and MLT3 encoding and transmission.
The circuitry 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 external1% 3.01KΩ resistor for the 1:1 transformer ratio.
The output signal 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 cable length, the equalizer
must adjust its characteristics to optimize performance. In this design, the variable equalizer makes an initial
estimation based on comparisons of incoming signal strength against some known cable characteristics, and then
tunes itself for optimization. This is an ongoing process and self-adjusts against environmental changes such as
temperature variations.
Next, the equalized signal goes through a DC restoration and data conversion block. The DC restoration circuit is
used to compensate for the effect of baseline wander and to 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. This signal is 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.
Scrambler/De-scrambler (100BASE-TX only)
The purpose of the scrambler is to spread the power spectrum of the signal to reduce electromagnetic interference
(EMI) and baseline wander. Transmitted data is scrambled through the use of an 11-bit wide linear feedback shift
register (LFSR). The scrambler generates a 2047-bit non-repetitive sequence, and the receiver then de-scrambles
the incoming data stream using the same sequence as at the transmitter.
10BASE-T Transmit
The 10BASE-T driver is incorporated with the 100BASE-TX driver to allow for transmission using the same
magnetic. 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 frequency when driven by an all-ones Manchesterencoded signal.
10BASE-T Receive
On the receive side, input buffers and level detecting squelch circuits are employed. A differential input receiver
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circuit and a phase-locked loop (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 pulse widths to prevent noise 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 KSZ8842M decodes a data frame. The
receiver clock is maintained active during idle periods in between data reception.
Power Management
The KSZ8842M features per port power-down mode. To save power, the user can power-down the port that is not in use
by setting bit 11 in either P1CR4 or P1MBCR register for port 1 and setting bit 11 in either P2CR4 or P2MBCR register for
port 2. To bring the port back up, reset bit 11 in these registers.
In addition, there is a full switch power-down mode. This mode shuts the entire switch down, when the PWRDN (pin 36) is
pulled down to low.
MDI/MDI-X Auto Crossover
To eliminate the need for crossover cables between similar devices, the KSZ8842M supports HP-Auto MDI/MDI-X and
IEEE 802.3u standard MDI/MDI-X auto crossover. HP-Auto MDI/MDI-X is the default.
The auto-sense function detects remote transmit and receive pairs and correctly assigns the transmit and receive pairs for
the KSZ8842M device. This feature is extremely useful when end users are unaware of cable types in addition to saving
on an additional uplink configuration connection. The auto-crossover feature can be disabled through the port control
registers.
The IEEE 802.3u standard MDI and MDI-X definitions are:
MDI
MDI-X
RJ45 Pins
Signals
RJ45 Pins
Signals
1
TD+
1
RD+
2
TD-
2
RD-
3
RD+
3
TD+
6
RD-
6
TD-
Table 1. MDI/MDI-X Pin Definitions
Straight Cable
A straight cable connects an MDI device to an MDI-X device or an MDI-X device to an MDI device. The following diagram
shows a typical straight cable connection between a network interface card (NIC) (MDI) and a switch, or hub (MDI-X).
10/100 Ethernet
Media Dependent Interface
10/100 Ethernet
Media Dependent Interface
1
1
2
2
Transmit Pair
Receive Pair
3
Straight
Cable
3
4
4
5
5
Receive Pair
Transmit Pair
6
6
7
7
8
8
Modular Connector
(RJ-45)
HUB
(Repeater or Switch)
Modular Connector
(RJ-45)
NIC
Figure 6. Typical Straight Cable Connection
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Crossover Cable
A crossover cable connects an MDI device to another MDI device, or an MDI-X device to another MDI-X device. The
following diagram shows a typical crossover cable connection between two switches or hubs (two MDI-X devices).
10/100 Ethernet
Media Dependent Interface
10/ 100 Ether net
Media Dep en dent Interface
1
Receiv e Pair
Crossover
Cable
1
Receive Pair
2
2
3
3
4
4
5
5
6
6
7
7
8
8
Tr ansmit Pa ir
Transmit Pair
Modular Connector (RJ-45)
HUB
(Repeater or Switch)
Modula r Connector (RJ-45)
HUB
(Repeat er or Sw itch)
Figure 7. Typical Crossover Cable Connection
Auto Negotiation
The KSZ8842M conforms to the auto negotiation protocol as described by the 802.3 committee to allow the channel to
operate at 10Base-T or 100Base-TX.
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 KSZ8842M is forced to bypass auto negotiation, 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 advertisements, the receiver is
listening for advertisements or a fixed signal protocol.
The link setup is shown in the following flow diagram (Figure 8).
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Start Auto Negotiation
Force Link Setting
NO
Parallel
Operation
YES
Bypass Auto Negotiation
and Set Link Mode
Attempt Auto
Negotiation
Listen for 100BASE-TX
Idles
Listen for 10BASE-T Link
Pulses
Join
Flow
NO
Link Mode Set ?
YES
Link Mode Set
Figure 8. Auto Negotiation and Parallel Operation
LinkMD Cable Diagnostics
The KSZ8842M LinkMD uses time domain reflectometry (TDR) to analyze the cabling plant for common cabling problems
such as open circuits, short circuits, and impedance mismatches.
LinkMD works by sending a pulse of known amplitude and duration down the MDI and MDI-X pairs and then analyzes the
shape of the reflected signal. Timing the pulse duration gives an indication of the distance to the cabling fault with a
maximum distance of 200m and an accuracy of +/–2m. Internal circuitry displays the TDR information in a user-readable
digital format in registers P1VCT[8:0] or P2VCT[8:0].
Note: cable diagnostics are only valid for copper connections –fiber-optic operation is not supported.
Access
LinkMD is initiated by accessing register P1VCT/P2VCT, the LinkMD Control/Status register, in conjunction with register
P1CR4/P2CR4, the 100BASE-TX PHY Controller register.
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Usage
LinkMD can be run at any time by making sure Auto MDIX has been disabled. To disable Auto-MDIX, write a ‘1’ to
P1CR4[10] for port 1 or P2CR4[10] for port 2 to enable manual control over the pair used to transmit the LinkMD pulse.
The self-clearing cable diagnostic test enable bit, P1VCT[15] for port 1 or P2VCT[15] for port 2 , is set to ‘1’ to start the
test on this pair.
When bit P1VCT[15] or P2VCT[15] returns to ‘0’, the test is complete. The test result is returned in bits P1VCT[14:13] or
P2VCT[14:13] and the distance is returned in bits P1VCT[8:0] or P2VCT[8:0]. The cable diagnostic test results are as
follows:
00 = Valid test, normal condition
01 = Valid test, open circuit in cable
10 = Valid test, short circuit in cable
11 = Invalid test, LinkMD failed
If P1VCT[14:13]=11 or P2VCT[14:13]=11, this indicates an invalid test, and occurs when the KSZ8842M is unable to shut
down the link partner. In this instance, the test is not run, as it is not possible for the KSZ8842M to determine if the
detected signal is a reflection of the signal generated or a signal from another source.
Cable distance can be approximated by the following formula:
P1VCT[8:0] X 0.4m for port 1 cable distance
P2VCT[8:0] X 0.4m for port 2 cable distance
This constant may be calibrated for different cabling conditions, including cables with a velocity of propagation that varies
significantly from the norm.
Functional Overview: MAC and Switch
Address Lookup
The internal lookup table stores MAC addresses and their associated information. It contains a 1K entry unicast address
learning table plus switching information.
The KSZ8842M is guaranteed to learn 1K addresses and distinguishes itself from hash-based lookup tables, which
depending on the operating environment and probabilities, may not guarantee the absolute number of addresses it can
learn.
Learning
The internal lookup engine updates its table with a new entry if the following conditions are met:
1. The received packet's Source Address (SA) does not exist in the lookup table.
2. The received packet is good without receiving errors; the packet size is legal length.
The lookup 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 to make room for the new entry.
Migration
The internal lookup engine also monitors whether a station has moved. If a station has moved, it updates the table
accordingly. Migration happens when the following conditions are met:
1. The received packet's SA is in the table but the associated source port information is different.
2. The received packet is good without receiving errors; the packet size is legal length.
The lookup engine updates the existing record in the table with the new source port information.
Aging
The lookup engine updates 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 lookup engine removes the record
from the table. The lookup engine constantly performs the aging process and continuously removes aging records. The
aging period is about 200 seconds. This feature can be enabled or disabled through Global Register SGCR1[10].
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Forwarding
The KSZ8842M forwards packets using the algorithm that is depicted in the following flowcharts. Figure 9 shows stage
one of the forwarding algorithm where the search engine looks up the VLAN ID, static table, and dynamic table for the
destination address, and comes up with “port to forward 1” (PTF1). PTF1 is then further modified by spanning tree, IGMP
snooping, port mirroring, and port VLAN processes to come up with “port to forward 2” (PTF2), as shown in Figure 10.
The packet is sent to PTF2.
Start
PTF1 = NULL
NO
VLAN ID
valid?
- Search VLAN table
- Ingress VLAN filtering
- Discard NPVID check
YES
Search complete.
Get PTF1 from
Static MAC Table
FOUND
Search Static
Table
This search is based on
DA or DA+FID
NOT
FOUND
Search complete.
Get PTF1 from
Dynamic MAC Table
FOUND
Dynamic Table
Search
This search is based on
DA+FID
NOT
FOUND
Search complete.
Get PTF1 from
VLAN table
PTF1
Figure 9. Destination Address Lookup Flow Chart in Stage One
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PTF1
Spanning Tree
Process
- 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 and MAC #2
IGMP Process
- IGMP will be forwarded to the host port
Port Mirror
Process
- RX Mirror
- TX Mirror
- RX or TX Mirror
- RX and TX Mirror
Port VLAN
Membership
Check
PTF2
Figure 10. Destination Address Resolution Flow Chart in Stage Two
The KSZ8842M will not forward the following packets:
1. Error packets.
These include framing errors, Frame Check Sequence (FCS) errors, alignment errors, and illegal size packet errors.
2. 802.3x pause frames.
The KSZ8842M intercepts these packets and performs the flow control.
3. "Local" packets.
Based on destination address (DA) lookup. If the destination port from the lookup table matches the port from which
the packet originated, the packet is defined as "local."
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Switching Engine
The KSZ8842M 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 switching engine has a 32KB internal frame buffer. This resource is shared between all the ports. There are a total of
256 buffers available. Each buffer is sized at 128B.
MAC Operation
The KSZ8842M strictly abides by IEEE 802.3 standards to maximize compatibility. Additionally, there is an added MAC
filtering function to filter Unicast packets. The MAC filtering function is useful in applications such as VoIP where
restricting certain packets reduces congestion and thus improves performance.
Inter Packet Gap (IPG)
If a frame is successfully transmitted, the minimum 96-bit time for IPG is measured between two consecutive packets. If
the current packet is experiencing collisions, the minimum 96-bit time for IPG is measured from carrier sense (CRS) to the
next transmit packet.
Back-Off Algorithm
The KSZ8842M implements the IEEE standard 802.3 binary exponential back-off algorithm in half-duplex mode, and
optional "aggressive mode" back-off. After 16 collisions, the packet is optionally dropped depending on the switch
configuration in SGCR1[8].
Late Collision
If a transmit packet experiences collisions after 512 bit times of the transmission, the packet is dropped.
legal Packet Size
The KSZ8842M discards packets less than 64 bytes and can be programmed to accept packet size up to 1536 bytes in
SGCR2[1]. The KSZ8842M can also be programmed for special applications to accept packet size up to 1916 bytes in
SGCR2[2].
Flow Control
The KSZ8842M supports standard 802.3x flow control frames on both transmit and receive sides.
On the receive side, if the KSZ8842M receives a pause control frame, the KSZ8842M 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 (while it is flow
controlled), only flow control packets from the KSZ8842M are transmitted.
On the transmit side, the KSZ8842M 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 KSZ8842M will flow control a port that has just received a packet if the destination port resource is busy. The
KSZ8842M issues a flow control frame (Xoff), containing the maximum pause time defined in IEEE standard 802.3x. Once
the resource is freed up, the KSZ8842M 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 provided to prevent the flow control mechanism from
being constantly activated and deactivated.
The KSZ8842M flow controls all ports if the receive queue becomes full.
Half-Duplex Backpressure
A half-duplex backpressure option (not in IEEE 802.3 standards) is also provided. The activation and deactivation
conditions are the same in full-duplex mode. If backpressure is required, the KSZ8842M sends preambles to defer the
other stations' transmission (carrier sense deference).
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To avoid jabber and excessive deference (as defined in the 802.3 standard), after a certain time, the KSZ8842M
discontinues the carrier sense and then raises it again quickly. This short silent time (no carrier sense) prevents other
stations from sending out packets thus keeping other stations in a carrier sense deferred state. If the port has packets to
send during a backpressure situation, the carrier sense type backpressure is interrupted and those packets are
transmitted instead. If there are no additional packets to send, carrier sense type backpressure is reactivated again until
switch resources free up. If a collision occurs, the binary exponential back-off algorithm is skipped and carrier sense is
generated immediately, thus reducing the chance of further collisions and carrier sense is maintained to prevent packet
reception.
To ensure no packet loss in 10 BASE-T or 100 BASE-TX half-duplex modes, the user must enable the following:
1. Aggressive back off (bit 8 in SGCR1)
2. No excessive collision drop (bit 3 in SGCR2)
Note: These bits are not set in default, since this is not the IEEE standard.
Broadcast Storm Protection
The KSZ8842M has an intelligent option to protect the switch system from receiving too many broadcast packets. As the
broadcast packets are forwarded to all ports except the source port, an excessive number of switch resources (bandwidth
and available space in transmit queues) may be utilized. The KSZ8842M has the option to include “multicast packets” for
storm control. The broadcast storm rate parameters are programmed globally, and can be enabled or disabled on a per
port basis in P1CR1[7] and P2CR1[7]. The rate is based on a 67ms interval for 100BT and a 670ms interval for 10BT. 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 the interval. The rate definition is described in SGCR3[15:8]. The default setting is 0x63 (99 decimal). This is
equal to a rate of 1%, calculated as follows:
148,800 frames/sec X 67 ms/interval X 1% = 99 frames/interval (approx.) = 0x63
Note: 148,800 frames/sec is based on 64-byte block of packets in 100BASE-T with 12 bytes of IPG and 8 bytes of
preamble between two packets.
Repeater Mode
When the KSZ8842M is set to repeater mode (SGCR3[7] = 1), it only works on 100BT half-duplex mode. In repeater
enabled mode, all ingress packets will be broadcast to the other two ports without MAC address checking and learning.
Before setting to the repeater mode, the user has to set bit 13 (100Mbps), bit 12 (auto-negotiation disabled) and bit 8 (half
duplex) in both P1MBCR and P2MBCR registers as well as set bit 6 (host half duplex) in SGCR3 register for the repeater
mode.
The latency in repeater mode is defined from the 1st bit of DA into the ingress port 1 to the 1st bit of DA out of the egress
port 2. The minimum is 270 ns and the maximum is 310 ns (one clock skew of 25 MHz between TX and RX).
Clock Generator
The X1 and X2 pins are connected to a 25 MHz crystal. X1 can also serve as the connector to a 3.3V, 25 MHz oscillator
(as described in the pin description).
The bus interface unit (BIU) uses BCLK (Bus Clock) for synchronous accesses. The maximum host port frequency is 50
MHz for VLBus-like and burst mode (32-bit interface only).
Bus Interface Unit (BIU)
The host interface of the BIU is designed to communicate with embedded processors. The host interface of the
KSZ8842M is a generic bus interface. Some glue logic may be required when the interface talks to various buses and
processors.
In terms of transfer type, the BIU can support two transfers: asynchronous transfer and synchronous transfer. To support
these transfers (asynchronous and synchronous), the BIU provides three groups of signals:
1. Synchronous signals
2. Asynchronous signals
3. Common signals are used for both synchronous and asynchronous transfers.
Since both synchronous and asynchronous signals are independent of each other, synchronous burst transfer and
asynchronous transfer can be mixed or interleaved but cannot be overlapped (due to the sharing of the common signals).
In terms of physical data bus size, the KSZ8842M supports 8, 16, and 32 bit host/industrial standard data bus sizes.
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Given a physical data bus size, the KSZ8842M supports 8, 16, or 32-bit data transfers depending on the size of the
physical data bus. For example, for a 32-bit system/host data bus, it allows 8, 16, and 32-bit data transfers (KSZ884232MQL); for a 16-bit system/host data bus, it allows 8 and 16-bit data transfers (KSZ8842-16MQL); and for 8-bit
system/host data bus, it only allows 8-bit data transfers (KSZ8842-16MQL).
Note that KSZ8842M does not support internal data byte-swap but it does support internal data word-swap. This means
that the system/host data bus HD[7:0] has to connect to both D[7:0] and D[15:8] for 8-bit data bus interfaces. However,
the system/host data bus HD[15:8] and HD[7:0] just connects to D[15:8] and D[7:0], respectively, for 16-bit data bus
interface; there is no need to connect HD[31:24] and HD[23:16] to D[31:24] and D[23:16].
Table 2 describes the BIU signal grouping.
Signal
Type(1)
Function
Common Signals
A[15:1]
I
Address
AEN
I
Address Enable
Address Enable asserted indicates memory address on the bus for DMA
access and since the device is an I/O device, address decoding is only enabled
when AEN is low.
BE3N, BE2N,
BE1N, BE0N
I
Byte Enable
BE0N
BE1N
BE2N
BE3N
Description
0
0
0
0
32-bit access (32-bit bus only)
0
0
1
1
Lower 16-bit (D[15:0]) access
1
1
0
0
0
1
1
1
Higher 16-bit (D[31:16]) access
(32-bit bus only)
Byte 0 (D[7:0]) access
1
0
1
1
Byte 1 (D[15:8]) access
1
1
0
1
1
1
1
0
Byte 2 (D[23:16]) access (32-bit
bus only)
Byte 3 (D[31:24]) access (32-bit
bus only)
Note 1: BE3N, BE2N, BE1N and BE0N are ignored when DATACSN is low
because 32 bit transfers are assumed.
Note 2: BE2N and BE3N are valid only for the KSZ8842-32 mode, and are NC
for the KSZ8842-16 mode.
D[31:16]
I/O
D[15:0]
I/O
Data
For KSZ8842-32 Mode only
Data
For both KSZ8842-32 and KSZ8842-16 Modes
ADSN
I
Address Strobe
The rising edge of ADSN is used to latch A[15:1], AEN, BE3N, BE2N, BE1N
and BE0N.
LDEVN
O
Local Device
This signal is a combinatorial decode of AEN and A[15:4], The A[15:4] is used
to compare against the Base Address Register.
DATACSN
I
Data Register Chip Select (For KSZ8842-32 Mode only)
This signal is used for central decoding architecture (mostly for embedded
application). When asserted, the device’s local decoding logic is ignored and
the 32-bit access to QMU Data Register is assumed.
INTRN
O
Interrupt
Synchronous Transfer Signals
VLBUSN
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VLBUSN = 1, burst cycle (both host/system and KSZ8842 can insert wait state)
CYCLEN
I
For VLBus-like access: used to sample SWR when asserted.
For burst access: used to connect to IOWC# bus signal to indicate burst write.
SWR
I
Write/Read
For VLBus-like access: used to indicate write (High) or read (Low) transfer.
For burst access: used to connect to IORC# bus signal to indicate burst read.
SRDYN
O
Synchronous Ready
For VLBus-like access: exactly the same signal definition of nSRDY in VLBus.
For burst access: insert wait state by the KSZ8842M whenever necessary
during the Data Register access.
RDYRTNN
I
Ready Return
For VLBus-like access: exactly like RDYRTNN signal in VLBus to end the
cycle.
For burst access: exactly like EXRDY signal in EISA to insert wait states. Note
that the wait states are inserted by system logic (memory) not by KSZ8842M.
BCLK
I
Bus Clock
Asynchronous Transfer Signals
RDN
I
Asynchronous Read
WRN
I
Asynchronous Write
ARDY
O
Asynchronous Ready
This signal is asserted (low) to insert wait states.
Note 1: I = Input. O = Output. I/O = Bi-directional.
Table 2. Bus Interface Unit Signal Grouping
Regardless of whether the transfer is synchronous or asynchronous, if the address latch is required, use the rising edge of
ADSN to latch the incoming signals A [15:1], AEN, BE3N, BE2N, BE1N, and BE0N.
Note: Whether the transfer is synchronous or asynchronous, if the local device decoder is used, LDEVN will be asserted
to indicate that the KSZ8842M is successfully targeted. Basically, signal LDEVN is a combinatorial decode of AEN and
A[15:4].
Asynchronous Interface
For asynchronous transfers, the asynchronous dedicated signals RDN (for read) or WRN (for write) toggle, but the
synchronous dedicated signals BCLK, CYCLEN, SWR, and RDYRTNN are de-asserted and stay at the same logic level
throughout the entire asynchronous transfer.
There is no data burst support for asynchronous transfer. All asynchronous transfers are single-data transfers. The BIU,
however, provides flexible asynchronous interfacing to communicate with various applications and architectures. Three
major ways of interfacing with the system (host) are.
1. Interfacing with the system/host relying on local device decoding and having stable address throughout the whole
transfer:
The typical example for this application is ISA-like bus interface using latched address signals as shown in the Figure
16. No additional address latch is required, therefore ADSN should be connected Low. The BIU decodes A[15:4] and
qualifies with AEN (Address Enable) to determine if the KSZ8842M switch is the intended target. The host utilizes the
rising edge of RDN to latch read data and the BIU will use rising edge of WRN to latch write data.
2. Interfacing with the system/host relying on local device decoding but not having stable address throughout the entire
transfer: the typical example for this application is EISA-like bus (non-burst) interface as shown in the Figure 17. This
type of interface requires ADSN to latch the address on the rising edge. The BIU decodes latched A[15:4] and
qualifies with AEN to determine if the KSZ8842M switch is the intended target. The data transfer is the same as the
first case.
3. Interfacing with the system/host relying on central decoding (KSZ8842-32 mode only).
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The typical example for this application is for an embedded processor having a central decoder on the system board
or within the processor. Connecting the chip select (CS) from system/host to DATACSN bypasses the local device
decoder. When the DATACSN is asserted, it only allows access to the Data Register in 32 bits and BE3N, BE2N,
BE1N, and BE0N are ignored as shown in the Figure 18. No other registers can be accessed by asserting DATACSN.
The data transfer is the same as in the first case. Independent of the type of asynchronous interface used. To insert a
wait state, the BIU will assert ARDY to prolong the cycle.
Synchronous Interface
For synchronous transfers, the synchronous dedicated signals CYCLEN, SWR, and RDYRTNN will toggle but the
asynchronous dedicated signals RDN and WRN are de-asserted and stay at the same logic level throughout the entire
synchronous transfer.
The synchronous interface mainly supports two applications, one for VLBus-like and the other for EISA-like (DMA type C)
burst transfers. The VLBus-like interface supports only single-data transfer. The pin option VLBUSN determines if it is a
VLBus-like or EISA-like burst transfer – if VLBUSN = 0, the interface is for VLBus-like transfer; if VLBUSN = 1, the
interface is for EISA-like burst transfer.
For VLBus-like transfer interface (VLBUSN = 0):
This interface is used in an architecture in which the device’s local decoder is utilized; that is, the BIU decodes latched
A[15:4] and qualifies with AEN (Address Enable) to determine if the switch is the intended target. No burst is
supported in this application. The M/nIO signal connection in VLBus is routed to AEN. The CYCLEN in this application
is used to sample the SWR signal when it is asserted. Usually, CYCLEN is one clock delay of ADSN. There is a
handshaking process to end the cycle of VLBus-like transfers. When the KSZ8842M is ready to finish the cycle, it
asserts SRDYN. The system/host acknowledges SRDYN by asserting RDYRTNN after the system/host has latched
the read data. The KSZ8842M holds the read data until RDYRTNN is asserted. The timing waveform is shown in
Figure 22 and Figure 23.
For EISA-like burst transfer interface (VLBUSN = 1):
The SWR is connected to IORC# in EISA to indicate the burst read and CYCLEN is connected to IOWC# in EISA to
indicate the burst write. Note that in this application, both the system/host/memory and KSZ8842M are capable of
inserting wait states. For system/host/memory to insert a wait state, assert the RDYRTNN signal; for the KSZ8842M
to insert the wait state, assert the SRDYN signal. The timing waveform is shown in Figure 20 and Figure 21.
Summary
Figure 11 shows the mapping from ISA-like, EISA-like and VLBus-like transactions to the switch’s BIU.
Figure 12 shows the connection for different data bus sizes.
Note: For the 8-bit data bus mode, the internal inverter is enabled and connected between BE0N and BE1N, so even
address will enable the BE0N and odd address will enable the BE1N.
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KSZ8842M BIU
Glue Logic
ISA
Non-burst
No Addr Latch
(ADSN = 0)
Local
decode
Asynchronous
Interface
Address Latch
Glue Logic
Central decode
EISA
Burst
VLBus
Central decode
(VLBUSN = 1)
Glue Logic
Glue Logic
Address Latch
Local
decode
(VLBUSN = 0)
Synchronous
Interface
Note: To use DATACSN & 32-bit only for Central decode
Figure 11. Mapping from ISA-like, EISA-like, and VLBus-like transactions to the KSZ8842M Bus
KSZ8842-16
KSZ8842-16
HA[1]
HA[1]
A[1]
A[1]
HA[15:2]
A[15:2]
HA[15:2]
A[15:2]
HD[7:0]
D[7:0]
HD[7:0]
D[15:8]
HD[15:8]
KSZ8842-32
GND
A[1]
HA[15:2]
A[15:2]
D[7:0]
HD[7:0]
D[7:0]
D[15:8]
HD[15:8]
D[15:8]
HD[23:16]
D[23:16]
HD[31:24]
D[31:24]
HA[0]
BE0N
HA[0]
BE0N
nHBE[0]
BE0N
VDD
BE1N
nSBHE
BE1N
nHBE[1]
BE1N
nHBE[2]
BE2N
nHBE[3]
BE3N
8-bit Data Bus
16-bit Data Bus
(for example: ISA-like)
32-bit Data Bus
(for example: EISA-like)
Figure 12. KSZ8842M 8-Bit, 16-Bit, and 32-Bit Data Bus Connections
BIU Implementation Principles
Since the KSZ8842M is an I/O device with 16 addressable locations, address decoding is based on the values of A15-A4
and AEN. Whenever DATACSN is asserted, the address decoder is disabled and a 32-bit transfer to Data Register is
assumed (BE3N – BE0N are ignored).
If address latching is required, the address is latched on the rising edge of ADSN and is transparent when ADSN=0.
1. Byte, word, and double-word data buses and accesses (transfers) are supported.
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2. Internal byte swapping is not implemented and word swapping is supported internally. Refer to Figure 12 for the
appropriate 8-bit, 16-bit, and 32-bit data bus connection.
3. Since independent sets of synchronous and asynchronous signals are provided, synchronous and asynchronous
cycles can be mixed or interleaved as long as they are not active simultaneously.
4. The asynchronous interface uses RDN and WRN signal strobes for data latching. If necessary, ARDY is deasserted on the leading edge of the strobe.
5. The VLBUS-like synchronous interface uses BCLK, ADSN, and SWR and CYCLEN to control read and write
operations and generate SRDYN to insert the wait state, if necessary, when VLBUSN = 0. For read, the data must
be held until RDYRTNN is asserted.
6. The EISA-like burst transfer is supported using synchronous interface signals and DATACSN when I/O signal
VLBUSN = 1. Both the system/host/memory and KSZ8842M are capable of inserting wait states. To set the
system/host/memory to insert a wait state, assert RDYRTNN signal. To set the KSZ8842M to insert a wait state,
assert SRDYN signal.
Queue Management Unit (QMU)
The Queue Management Unit (QMU) manages packet traffic between the MAC/PHY interface and the system host. It has
built-in packet memory for receive and transmit functions called TXQ (Transmit Queue) and RXQ (Receive Queue). Each
queue contains 4KB of memory for back-to-back, non-blocking frame transfer performance. It provides a group of control
registers for system control, frame status registers for current packet transmit/receive status, and interrupts to inform the
host of the real time TX/RX status.
Transmit Queue (TXQ) Frame Format
The frame format for the transmit queue is shown in the following Table 3. The first word contains the control information
for the frame to transmit. The second word is used to specify the total number of bytes of the frame. The packet data
follows. The packet data area holds the frame itself. It may or may not include the CRC checksum depending on whether
hardware CRC checksum generation is enabled.
Multiple frames can be pipelined in both the transmit queue and receive queue as long as there is enough queue memory,
thus avoiding overrun. For each transmitted frame, the transmit status information for the frame is located in the TXSR
register.
Packet Memory
Address Offset
Bit 15
0
Control Word
2
Byte Count
4 - up
Packet Data
Bit 0
2nd Byte
1st Byte
(maximum size is 1916)
Table 3: Transmit Queue Frame Format
Since multiple packets can be pipelined into the TX packet memory for transmit, the transmit status reflects the
status of the packet that is currently being transferred on the MAC interface (which may or may not be the last
queued packet in the TX queue).
The transmit control word is the first 16-bit word in the TX packet memory, followed by a 16-bit byte count. It must
be word aligned. Each control word corresponds to one TX packet. Table 4 gives the transmit control word bit
fields.
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Bit
Description
15
TXIC Transmit Interrupt on Completion
When bit is set, the KSZ8842M sets the transmit interrupt after the present frame has been
transmitted.
Reserved
TXDPN Transmit Destination Port Number
When bit is set, this field indicates the destination port(s) where the packet is forwarded
from host system. Set bit 8 to indicate that port 1 is the destination port. Set bit 9 to
indicate that port 2 is the destination port.
Setting all ports to 1 causes the switch engine to broadcast the packet to both ports.
Setting all bits to 0 has no effect. The internal switch engine forwards the packets
according to the switching algorithm in its MAC lookup table.
Reserved
TXFID Transmit Frame ID
This field specifies the frame ID that is used to identify the frame and its associated status
information in the transmit status register TXSR[5:0].
14-10
9-8
7-6
5-0
Table 4. Transmit Control Word Bit Fields
The transmit Byte Count specifies the total number of bytes to be transmitted from the TXQ. Its format is given in Table 5.
Bit
Description
15-11
10-0
Reserved
TXBC Transmit Byte Count
Transmit Byte Count. Hardware uses the byte count information to conserve the TX buffer
memory for better utilization of the packet memory.
Note: The hardware behavior is unknown if an incorrect byte count information is written to
this field. Writing a 0 value to this field is not permitted.
Table 5. Transmit Byte Count Format
The data area contains six bytes of Destination Address (DA) followed by six bytes of Source Address (SA), followed by a
variable-length number of bytes. On transmit, all bytes are provided by the CPU, including the source address. The
KSZ8842M does not insert its own source address. The 802.3 Frame Length word (Frame Type in Ethernet) is not
interpreted by the KSZ8842M. It is treated transparently as data for transmit operations.
Receive Queue (RXQ) Frame Format
The frame format for the receive queue is shown in Table 6. The first word contains the status information for the frame
received. The second word is the total number of bytes of the RX frame. Following that is the packet data area. The
packet data area holds the frame itself. It may or may not include the CRC checksum depending on whether hardware
CRC stripping is enabled.
Packet Memory
Address Offset
Bit 15
0
Status Word
2
4 - up
Byte Count
Packet Data
(maximum size is 1916)
nd
2
Byte
Bit 0
st
1 Byte
Table 6: Receive Queue Frame Format
For receive, the packet receive status always reflects the receive status of the packet received in the current RX packet
memory (see Table 7). The RXSR register indicates the status of the current received frame.
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Bit
Description
15
RXFV Receive Frame Valid
When bit is set, indicates that the present frame in the receive packet memory is valid and
received from MAC/PHY. The status information currently in this location is also valid.
When bit is reset, indicates that there is either no pending receive frame or current frame is
still in the process of receiving and has not completed yet.
Reserved
RXSPN Receive Source Port Number
When bit is set, this field indicates the source port where the packet was received. (Setting
bit 9 = 0 and bit 8 = 1 indicates the packet was received from port 1. Setting bit 9 = 1 and bit
8 = 0 indicates that the packet was received from port 2. Valid port is either port 1 or port 2.
RXBF Receive Broadcast Frame
When bit is set, indicates that this frame has a broadcast address.
RXMF Receive Multicast Frame
When bit is set, it indicates that this frame has a multicast address (including the broadcast
address).
RXUF Receive Unicast Frame
When bit is set, indicates that this frame has a unicast address.
Reserved
RXFT Receive Frame Type
When bit is set, indicates that the frame is an Ethernet-type frame (frame length is greater
than 1500 bytes). When clear, indicate that the frame is an IEEE 802.3 frame.
This bit is not valid for runt frames.
RXTL Receive Frame Too Long
When bit is set, indicates that the frame length exceeds the maximum size of 1518 bytes.
Frames too long are passed to the host only if the pass bad frame bit is set.
Note: Frame too long is only a frame length indication and does not cause any frame
truncation.
RXRF Receive Runt Frame
When bit is set, indicates that a frame was damaged by a collision or premature termination
before the collision window has passed. Runt frames are passed to the host only if the pass
bad frame bit is set.
RXCE Receive CRC Error
When bit is set, indicates that a CRC error has occurred on the current received frame. CRC
error frame are passed to the host only if the pass bad frame bit is set.
14-10
9-8
7
6
5
4
3
2
1
0
Table 7. FRXQ Packet Receive Status
Table 8 gives the format of the RX byte count field.
Bit
Description
15-11
10-0
Reserved
RXBC Receive Byte Count
Receive Byte Count.
Table 8. FRXQ RX Byte Count Field
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Advanced Switch Functions
Spanning Tree Support
To support spanning tree, the host port is the designated port for the processor.
The other ports can be configured in one of the five spanning tree states via “transmit enable”, “receive enable” and
“learning disable” register settings in registers P1CR2 and P2CR2 for ports 1 and 2, respectively. Table 9 shows the port
setting and software actions taken for each of the five spanning tree states.
Disable State
Port Setting
Software Action
The port should
not forward or
receive any
packets. Learning
is disabled.
“transmit
enable = 0,
receive
enable = 0,
learning
disable =1”
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 MAC table” with “overriding bit” set) and the processor should
discard those packets. Address learning is disabled on the port in this
state.
Blocking State
Port Setting
Software Action
Only packets to
the processor are
forwarded.
“transmit
enable = 0,
receive
enable = 0,
learning
disable =1”
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 (for example, 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
Port Setting
Software Action
Only packets to
and from the
processor are
forwarded.
Learning is
disabled.
“transmit
enable = 0,
receive
enable = 0,
learning
disable =1”
The processor should program the “Static MAC table” with the entries that it
needs to receive (for example, 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.
Address learning is disabled on the port in this state.
Learning State
Port Setting
Software Action
Only packets to
and from the
processor are
forwarded.
Learning is
enabled.
“transmit
enable = 0,
receive
enable = 0,
learning
disable = 0”
The processor should program the “Static MAC table” with the entries that it
needs to receive (for example, 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.
Address learning is enabled on the port in this state.
Forwarding
State
Port Setting
Software Action
Packets are
forwarded and
received normally.
Learning is
enabled.
“transmit
enable = 1,
receive enable
= 1, learning
disable = 0”
The processor programs the “Static MAC table” with the entries that it
needs to receive (for example, BPDU packets). The “overriding” bit is set so
that the switch forwards those specific packets to the processor. The
processor can send packets to the port(s) in this state. Address learning is
enabled on the port in this state.
Table 9: Spanning Tree States
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IGMP Support
For Internet Group Management Protocol (IGMP) support in Layer 2, the KSZ8842M provides two components:
“IGMP” Snooping
The KSZ8842M traps IGMP packets and forwards them only to the processor (host port). The IGMP packets are
identified as IP packets (either Ethernet IP packets, or IEEE 802.3 SNAP IP packets) with IP version = 0x4 and
protocol version number = 0x2.
“Multicast Address Insertion” in the Static MAC Table
Once the multicast address is programmed in the Static MAC Table, the multicast session is trimmed to the
subscribed ports, instead of broadcasting to all ports.
IPv6 MLD Snooping
The KSZ8842M traps IPv6 Multicast Listener Discovery (MLD) packets and forwards them only to the processor
(host port). MLD snooping is controlled by SGCR2[13] (MLD snooping enable) and SGCR2[12] (MLD option).
Setting SGCR2[13] causes the KSZ8842M to trap packets that meet all of the following conditions:
•
IPv6 multicast packets
•
Hop count limit = 1
•
IPv6 next header = 1 or 58 (or = 0 with hop-by-hop next header = 1 or 58)
•
If SGCR2[12] = 1, IPv6 next header = 43, 44, 50, 51, or 60 (or =0 with hop-by-hop next header = 43, 44,
50, 51, or 60)
Port Mirroring Support
KSZ8842M supports “Port Mirroring” comprehensively as:
“receive only” mirror on a port
All the packets received on the port are mirrored on the sniffer port. For example, port 1 is programmed to be
“receive sniff” and the host port is programmed to be the “sniffer port”. A packet received on port 1 is destined to
port 2 after the internal lookup. The KSZ8842M forwards the packet to both port 2 and the host port. The
KSZ8842M can optionally even forward “bad” received packets to the “sniffer port”.
“transmit only” mirror on a port
All the packets transmitted on the port are mirrored on the sniffer port. For example, port 1 is programmed to be
“transmit sniff” and the host port is programmed to be the “sniffer port”. A packet received on port 2 is destined to
port 1 after the internal lookup. The KSZ8842M forwards the packet to both port 1 and the host port.
“receive and transmit” mirror on two ports
All the packets received on port A and transmitted on port B are mirrored on the sniffer port. To turn on the “AND”
feature, set register SGCR2, bit 8 to “1”. For example, port 1 is programmed to be “receive sniff”, port 2 is
programmed to be “transmit sniff”, and the host port is programmed to be the “sniffer port”. A packet received on
port 1 is destined to port 2 after the internal lookup. The KSZ8842M forwards the packet to both port 2 and the
host port.
Multiple ports can be selected as “receive sniff” or “transmit sniff”. In addition, any port can be selected as the “sniffer
port”. All these per port features can be selected through registers P1CR2, P2CR2, and P3CR2 for ports 1, 2, and the
host port, respectively.
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IEEE 802.1Q VLAN Support
The KSZ8842M supports 16 active VLANs out of the 4096 possible VLANs specified in the IEEE 802.1Q specification.
KSZ8842M provides a 16-entry VLAN table, which converts the 12-bits VLAN ID (VID) to the 4-bits Filter ID (FID) for
address lookup. If a non-tagged or null-VID-tagged packet is received, the ingress port default VID is used for lookup. In
VLAN mode, the lookup process starts with VLAN table lookup to determine whether the VID is valid. If the VID is not
valid, the packet is dropped and its address is not learned. If the VID is valid, the FID is retrieved for further lookup. The
FID + Destination Address (FID+DA) are used to determine the destination port. The FID + Source Address (FID+SA) are
used for address learning. (See Tables 10 and 11.)
DA found in
Static MAC
Table?
Use FID flag?
FID match?
DA+FID found in
Dynamic MAC
Table?
No
Don’t care
Don’t care
No
No
Don’t care
Don’t care
Yes
Yes
0
Don’t care
Don’t care
Yes
1
No
No
Yes
1
No
Yes
Yes
1
Yes
Don’t care
Action
Broadcast to the membership ports
defined in the VLAN Table bits [18:16]
Send to the destination port defined in the
Dynamic MAC Address Table bits [53:52]
Send to the destination port(s) defined in
the Static MAC Address Table bits [50:48]
Broadcast to the membership ports
defined in the VLAN Table bits [18:16]
Send to the destination port defined in the
Dynamic MAC Address Table bits [53:52]
Send to the destination port(s) defined in
the Static MAC Address Table bits [50:48]
Table 10. FID+DA Lookup in VLAN Mode
FID+SA found in Dynamic
MAC Table?
Action
No
Learn and add FID+SA to the Dynamic MAC Address Table
Yes
Update time stamp
Table 11. FID+SA Lookup in VLAN Mode
QoS Priority Support
The KSZ8842M provides Quality of Service (QoS) for applications such as VoIP and video conferencing. Offering four
priority queues per port, the per-port transmit queue can be split into four priority queues: Queue 3 is the highest priority
queue and Queue 0 is the lowest priority queue. Bit 0 of registers P1CR1, P2CR1, and P3CR1 is used to enable split
transmit queues for ports 1, 2, and the host port, respectively.
Port-Based Priority
With port-based priority, each ingress port is individually classified as a high-priority receiving port. All packets received at
the high-priority receiving port are marked as high priority and are sent to the high-priority transmit queue if the
corresponding transmit queue is split. Bit 4 and 3 of registers P1CR1, P2CR1, and P3CR1 is used to enable port-based
priority for ports 1, 2, and the host port, respectively.
802.1p-Based Priority
For 802.1p-based priority, the KSZ8842M examines the ingress (incoming) packets to determine whether they are tagged.
If tagged, the 3-bit priority field in the VLAN tag is retrieved and compared against the “priority mapping” value, as
specified by the register SGCR6. The “priority mapping” value is programmable.
Figure 13 illustrates how the 802.1p priority field is embedded in the 802.1Q VLAN tag.
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7
1
6
6
2
2
2
46-1500
4
Preamble
DA
SA
VPID
TCI
length
Data
FCS
Bits
802.1q VLAN Tag
16
Tagged Packet Type
(8100 for Ethernet)
3
1
802.1p
CFI
Bytes
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SFD
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VLAN ID
Figure 13. 802.1p Priority Field Format
802.1p based priority is enabled by bit 5 of registers P1CR1, P2CR1, and P3CR1 for ports 1, 2, and the host port,
respectively.
The KSZ8842M provides the option to insert or remove the priority tagged frame's header at each individual egress port.
This header, consisting of the 2 bytes VLAN protocol ID (VPID) and the 2 bytes tag control information field (TCI), is also
referred to as the 802.1Q VLAN tag.
Tag insertion is enabled by bit 2 of registers P1CR1, P2CR1, and P3CR1 for ports 1, 2, and the host port, respectively.
At the egress port, untagged packets are tagged with the ingress port’s default tag. The default tags are programmed in
register sets P1VIDCR, P2VIDCR, and P3VIDCR for ports 1, 2 and the host port, respectively. The KSZ8842M does not
add tags to already tagged packets.
Tag removal is enabled by bit 1 of registers P1CR1, P2CR1, and P3CR1 for ports 1, 2, and the host port, respectively. At
the egress port, tagged packets will have their 802.1Q VLAN Tags removed. The KSZ8842M will not modify untagged
packets.
The CRC is recalculated for both tag insertion and tag removal.
802.1p priority field re-mapping is a QoS feature that allows the KSZ8842M to set the “User Priority Ceiling” at any
ingress port. If the ingress packet’s priority field has a higher priority value than the default tag’s priority field of the ingress
port, the packet’s priority field is replaced with the default tag’s priority field. The “User Priority Ceiling” is enabled by bit 3
of registers P1CR2, P2CR2, and P3CR2 for ports 1, 2, and the host port, respectively.
DiffServ based Priority
DiffServ-based priority uses the ToS registers shown in the Priority Control Registers section. The ToS priority control
registers implement a fully decoded, 128-bit Differentiated Services Code Point (DSCP) register to determine packet
priority from the 6-bit ToS field in the IP header. When the most significant 6 bits of the ToS field are fully decoded, the
resultant of the 64 possibilities is compared with the corresponding bits in the DSCP register to determine priority.
Rate Limiting Support
The KSZ8842M supports hardware rate limiting from 64 Kbps to 88 Mbps, independently on the “receive side” and on the
“transmit side” on a per port basis. For 10-base T, a rate setting above 10 Mbps means the rate is not limited. On the
receive side, the data receive rate for each priority at each port can be limited by setting up Ingress Rate Control
Registers. On the transmit side, the data transmit rate for each priority queue at each port can be limited by setting up
Egress Rate Control Registers. The size of each frame has options to include minimum IFG (Inter Frame Gap) or
Preamble byte, in addition to the data field (from packet DA to FCS).
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For ingress rate limiting, KSZ8842M provides options to selectively choose frames from all types, multicast, broadcast,
and flooded unicast frames. The KSZ8842M counts the data rate from those selected type of frames. Packets are
dropped at the ingress port when the data rate exceeds the specified rate limit.
For egress rate limiting, the Leaky Bucket algorithm is applied to each output priority queue for shaping output traffic .
Inter frame gap is stretched on a per frame base to generate smooth, non-burst egress traffic. The throughput of each
output priority queue is limited by the egress rate specified.
If any egress queue receives more traffic than the specified egress rate throughput, packets may be accumulated in the
output queue and packet memory. After the memory of the queue or the port is used up, packet dropping or flow control
will be triggered. As a result of congestion, the actual egress rate may be dominated by flow control/dropping at the
ingress end, and may be therefore slightly less than the specified egress rate.
To reduce congestion, it is a good practice to make sure the egress bandwidth exceeds the ingress bandwidth.
MAC Filtering Function
Use the static table to assign a dedicated MAC address to a specific port. When a unicast MAC address is not recorded in
the static table, it is also not learned in the dynamic MAC table. The KSZ8842M includes an option that can filter or
forward unicast packets for an unknown MAC address. This option is enabled by SGCR7[7].
The unicast MAC address filtering function is useful in preventing the broadcast of unicast packets that could degrade the
quality of this port in applications such as voice over Internet Protocol (VoIP).
Configuration Interface
The KSZ8842M operates only as a managed switch.
EEPROM Interface
It is optional in the KSZ8842M to use an external EEPROM. In the case that an EEPROM is not used, the EEEN pin must
be tied Low or floating.
The external serial EEPROM with a standard microwire bus interface is used for non-volatile storage of information such
as the host MAC address, base address, and default configuration settings. The KSZ8842M can detect if the EEPROM is
a 1KB (93C46) or 4KB (93C66) EEPROM device (the 93C46 and the 93C66 are typical EEPROM devices). The
EEPROM is organized as 16-bit mode.
If the EEEN pin is pulled high, the KSZ8842M performs an automatic read of the external EEPROM words 0H to 6H after
the de-assertion of Reset. The EEPROM values are placed in certain host-accessible registers. EEPROM read/write
functions can also be performed by software read/writes to the EEPCR registers.
The KSZ8842M EEPROM format is given below.
WORD
15
0H
Base Address
8
7
1H
Host MAC Address Byte 2
Host MAC Address Byte 1
2H
Host MAC Address Byte 4
Host MAC Address Byte 3
3H
Host MAC Address Byte 6
Host MAC Address Byte 5
4H
Reserved
5H
Reserved
6H
ConfigParam (see Table 13)
7H-3FH
Not used for KSZ8842M (available for user to use)
0
Table 12. EEPROM Format
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The format for ConfigParam is shown in Table 13.
Bit
Bit Name
Description
15 -2
Reserved
Reserved
1
Clock_Rate
Internal clock rate selection
0: 125 MHz
1: 25 MHz
Note: At power up, this chip operates on 125 MHz clock. The internal frequency can be
dropped to 25 MHz via the external EEPROM.
0
ASYN_8bit
Async 8-bit or 16-bit bus select
1= bus is configured for 16-bit width
0= bus is configured for 8-bit width
(32-bit width, KSZ8842-32, don’t care this bit setting)
Table 13. ConfigParam Word in EEPROM Format
Loopback Support
The KSZ8842M provides loopback support for remote diagnostic of failure. In loopback mode, the speed at both PHY
ports will be set to 100BASE-TX full-duplex mode. Two types of loopback are supported: Far-end Loopback and Near-end
(Remote) Loopback.
Far-end Loopback
Far-end loopback is conducted between the KSZ8842M’s two PHY ports. The loopback path starts at the “Originating.”
PHY port’s receive inputs (RXP/RXM), wraps around at the “loopback” PHY port’s PMD/PMA, and ends at the
“Originating” PHY port’s transmit outputs (TXP/TXM).
Bit [8] of registers P1CR4 and P2CR4 is used to enable far-end loopback for ports 1 and 2, respectively. Alternatively, Bit
[14] of registers P1MBCR and P2MBCR can also be used to enable far-end loopback. The port 2 far-end loopback path is
illustrated in the Figure 14.
Near-end (Remote) Loopback
Near-end (Remote) loopback is conducted at either PHY port 1 or PHY port 2 of the KSZ8842M. The loopback path starts
at the PHY port’s receive inputs (RXPx/RXMx), wraps around at the same PHY port’s PMD/PMA, and ends at the PHY
port’s transmit outputs (TXPx/TXMx).
Bit [1] of registers P1PHYCTRL and P2PHYCTRL is used to enable near-end loopback for ports 1 and 2, respectively.
Alternatively, Bit [9] of registers P1SCSLMD and P2SCSLMD can also be used to enable near-end loopback. The both
ports 1 and 2 near-end loopback paths are illustrated in the following Figure 15.
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R X P 1 /
R X M 1
O r ig in a tin g
P H Y P o r t 1
T X P 1 /
T X M 1
P M D 1 /P M A 1
P C S 1
M A C 1
S w it c h
M A C 2
P C S 2
P M D 2 /P M A 2
P H Y P o r t 2
F a r -e n d L o o p b a c k
Figure 14. Port 2 Far-End Loopback Path
R X P 1 /
R X M 1
P H Y P o rt 1
N e a r-e n d (re m o te )
L o o p b a c k
T X P 1 /
T X M 1
P M D 1 /P M A 1
P C S 1
M A C 1
S w itc h
M A C 2
P C S 2
P M D 2 /P M A 2
T X P 2 /
T X M 2
P H Y P o rt 2
N e a r-e n d (re m o te )
L o o p b a c k
R X P 2 /
R X M 2
Figure 15. Port 1 and port 2 Near-End (Remote) Loopback Path
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CPU Interface I/O Registers
The KSZ8842M provides an EISA-like, ISA-like, or VLBUS-like bus interface for the CPU to access its internal I/O
registers. I/O registers serve as the address that the microprocessor uses when communicating with the device. This is
used for configuring operational settings, reading or writing control, status information, and transferring packets by reading
and writing through the packet data registers.
I/O Registers
Input/Output (I/O) registers are limited to 16 locations as required by most ISA bus-based systems; therefore, registers
are assigned to different banks. The last word of the I/O register locations (0xE - 0xF) is shared by all banks and can be
used to change the bank in use.
The following I/O Space Mapping Tables apply to 8, 16 or 32-bit bus products. Depending on the bus interface used and
byte enable signals (BE[3:0]N control byte access), each I/O access can be performed as an 8-bit, 16-bit, or 32-bit
operation. (The KSZ8842M is not limited to 8/16-bit performance and 32-bit read/write are also supported).
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Internal I/O Space Mapping
I/O Register Location
32-Bit
16-Bit
8-Bit
Base
Address
[7:0]
0x1
Base
Address
[15:8]
0x0
0x0
To
0x3
Bank 0
0x0
- 0x1
Bank Location
Bank 1
Reserved
0x2
0x2
- 0x3
Reserved
Reserved
Reserved
Reserved
0x3
0x4
0x4
- 0x5
0x5
0x4
To
0x7
Bus
Status
[7:0]
Error
0x6
Error
0x7
Bus
Status
[15:8]
0x6
- 0x7
0x8
0x8
- 0x9
0x9
0x8
Bus
Burst
Length
[7:0]
Bus
Burst
Length
[15:8]
Reserved
Reserved
Bank 2
Bank 3
Bank 4
Host
MAC On-Chip Bus
Address Low Control
[7:0]
[7:0]
Host
MAC On-Chip Bus
Address Low Control
[15:8]
[15:8]
Host
MAC EEPROM
Address Mid Control
[7:0]
[7:0]
Host
MAC EEPROM
Address Mid Control
[15:8]
[15:8]
Host
MAC Memory BIST
Address High Info
[7:0]
[7:0]
Host
MAC Memory BIST
Address High Info
[15:8]
[15:8]
Global
Reset
[7:0]
Reserved
Global
Reset
[15:8]
Bus
Configuration
[7:0]
Reserved
Bus
Configuration
[15:8]
Bank 5
Bank 6
Bank 7
Reserved
Reserved
Reserved
Reserved
Reserved
To
0xB
0xA
0xA
Reserved
- 0xB
0xB
0xC
0xC
Reserved
- 0xD
0xD
0xC
To
0xF
0xE
Bank Select [7:0]
0xF
Bank Select [15:8]
0xE
- 0xF
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Internal I/O Space Mapping (continued)
I/O Register Location
32-Bit
16-Bit
8-Bit
Bank Location
Bank 8
Bank 9
Bank 10
Bank 11
Bank 12
Bank 13
Bank 14
Bank 15
0x0
0x0
Reserved
- 0x1
0x1
0x0
To
0x3
0x2
0x2
Reserved
- 0x3
0x3
0x4
0x4
Reserved
- 0x5
0x5
0x4
To
0x7
0x6
0x6
Reserved
- 0x7
0x7
0x8
0x8
Reserved
- 0x9
0x9
0x8
To
0xB
0xA
0xA
Reserved
- 0xB
0xB
0xC
0xC
Reserved
- 0xD
0xD
0xC
To
0xF
0xE
Bank Select [7:0]
0xF
Bank Select [15:8]
0xE
- 0xF
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Internal I/O Space Mapping (continued)
I/O Register Location
32-Bit
16-Bit
8-Bit
0x0
0x0
- 0x1
0x1
0x0
To
0x3
0x2
0x2
- 0x3
0x3
0x4
0x4
- 0x5
0x5
0x4
To
0x7
Bank Location
Bank 16
Transmit
Control
[7:0]
Transmit
Control
[15:8]
Transmit
Status
[7:0]
Transmit
Status
[15:8]
Receive
Control
[7:0]
Receive
Control
[15:8]
0x6
Reserved
0x7
0x8
0x8
- 0x9
0x9
0x8
To
0xB
TXQ
Command
[7:0]
TXQ
Command
[15:8]
RXQ
Command
[7:0]
RXQ
Command
[15:8]
TX Frame
Data Pointer
[7:0]
TX Frame
Data Pointer
[15:8]
RX Frame
Data Pointer
[7:0]
0x6
- 0x7
Bank 17
TXQ Memory
Information
[7:0]
TXQ Memory
Information
[15:8]
RX Frame
Data Pointer
[15:8]
QMU Data
Low
[7:0]
QMU Data
Low
[15:8]
0xA
RXQ Memory
Information
[7:0]
QMU Data
High
[7:0]
0xB
RXQ Memory
Information
[15:8]
QMU Data
High
[15:8]
0xA
- 0xB
Bank 18
Bank 19
Interrupt
Enable
[7:0]
Interrupt
Enable
[15:8]
Interrupt
Status
[7:0]
Multicast
Table 0
[7:0]
Multicast
Table 0
[15:8]
Multicast
Table 1
[7:0]
Interrupt
Status
[15:8]
Receive
Status
[7:0]
Receive
Status
[15:8]
Receive Byte
Counter
[7:0]
Receive Byte
Counter
[15:8]
Multicast
Table 1
[15:8]
Multicast
Table 2
[7:0]
Multicast
Table 2
[15:8]
Multicast
Table 3
[7:0]
Multicast
Table 3
[15:8]
Bank 20
Bank 21
Bank 23
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Bank 22
Reserved
Reserved
0xC
0xC
Reserved
- 0xD
0xD
0xC
To
0xF
0xE
Bank Select [7:0]
0xF
Bank Select [15:8]
0xE
- 0xF
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KSZ8842-16/32 MQL/MVL
Internal I/O Space Mapping (continued)
I/O Register Location
32-Bit
16-Bit
8-Bit
Bank Location
Bank 24
Bank 25
Bank 26
Bank 27
Bank 28
Bank 29
Bank 30
Bank 31
0x0
0x0
Reserved
- 0x1
0x1
0x0
To
0x3
0x2
0x2
Reserved
- 0x3
0x3
0x4
0x4
Reserved
- 0x5
0x5
0x4
To
0x7
0x6
0x6
Reserved
- 0x7
0x7
0x8
0x8
Reserved
- 0x9
0x9
0x8
To
0xB
0xA
0xA
Reserved
- 0xB
0xB
0xC
0xC
Reserved
- 0xD
0xD
0xC
To
0xF
0xE
Bank Select [7:0]
0xF
Bank Select [15:8]
0xE
- 0xF
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KSZ8842-16/32 MQL/MVL
Internal I/O Space Mapping (continued)
I/O Register Location
32-Bit
16-Bit
8-Bit
0x0
0x0
- 0x1
0x1
0x0
To
0x3
0x2
0x2
- 0x3
0x3
0x4
0x4
- 0x5
0x5
0x4
To
0x7
0x6
0x6
- 0x7
0x7
0x8
0x8
- 0x9
0x9
0x8
To
0xB
0xA
0xA
- 0xB
0xB
Bank Location
Bank 32
Bank 33
Switch ID and
Enable
[7:0]
Switch ID and
Enable
[15:8]
Switch Global
Control 1
[7:0]
Switch Global
Control 6
[7:0]
Switch Global
Control 6
[15:8]
Switch Global
Control 7
[7:0]
Bank 34
Bank 35
Bank 36
Reserved
Bank 37
Bank 38
Bank 39
MAC
Address 1
[7:0]
MAC
Address 1
[15:8]
MAC
Address 2
[7:0]
Reserved
Switch Global Switch Global
Control 1
Control 7
[15:8]
[15:8]
Switch Global
Control 2
[7:0]
Switch Global
Control 2
[15:8]
Switch Global
Control 3
[7:0]
Switch Global
Control 3
[15:8]
Switch Global
Control 4
[7:0]
Switch Global
Control 4
[15:8]
Switch Global
Control 5
[7:0]
Reserved
MAC
Address 2
[15:8]
MAC
Address 3
[7:0]
MAC
Address 3
[15:8]
Reserved
Reserved
Reserved
Switch Global
Control 5
[15:8]
0xC
0xC
Reserved
- 0xD
0xD
0xC
To
0xF
0xE
Bank Select [7:0]
0xF
Bank Select [15:8]
0xE
- 0xF
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KSZ8842-16/32 MQL/MVL
Internal I/O Space Mapping (continued)
I/O Register Location
32-Bit
16-Bit
8-Bit
Bank 40
Bank 41
Bank 42
Bank 43
0x0
TOS Priority TOS Priority Indirect
Control 1
Control 7
Access Ctrl.
[7:0]
[7:0]
[7:0]
0x1
TOS Priority TOS Priority Indirect
Control 1
Control 7
Access
[15:8]
[15:8]
[15:8]
0x2
TOS Priority TOS Priority Indirect
Control 2
Control 8
Access Data 1
[7:0]
[7:0]
[7:0]
0x3
TOS Priority TOS Priority Indirect
Control 2
Control 8
Access Data 1
[15:8]
[15:8]
[15:8]
0x4
TOS Priority
Control 3
[7:0]
0x0
Bank 44
Ctrl.
0x2
- 0x3
0x4
- 0x5
0x5
0x4
To
0x7
0x6
0x6
- 0x7
0x7
0x8
0x8
- 0x9
0x9
0x8
To
0xB
0xA
0xA
- 0xB
0xB
TOS Priority
Control 3
[15:8]
TOS Priority
Control 4
[7:0]
TOS Priority
Control 4
[15:8]
TOS Priority
Control 5
[7:0]
TOS Priority
Control 5
[15:8]
TOS Priority
Control 6
[7:0]
TOS Priority
Control 6
[15:8]
Reserved
Indirect
Access Data 2
[7:0]
Reserved
Indirect
Access Data 2
[15:8]
Reserved
Indirect
Access Data 3
[7:0]
Reserved
Indirect
Access Data 3
[15:8]
Indirect
Access Data 4
[7:0]
Reserved
Reserved
Reserved
Indirect
Access Data 4
[15:8]
Indirect
Access Data 5
[7:0]
Reserved
Indirect
Access Data 5
[15:8]
Reserved
Bank 46
Bank 47
PHY1 MIIRegister
Basic Control
[7:0]
PHY2 MIIPHY1 LinkMD
Control/Status
Register
Basic Control [7:0]
[7:0]
Digital Test
Status
[15:8]
PHY1 MIIRegister
Basic Control
[15:8]
PHY2 MIIPHY1 LinkMD
Register
Control/Status
Basic Control [15:8]
[15:8]
Analog Test
Status
[7:0]
Digital Test
Control
[7:0]
PHY1 MIIRegister
Basic Status
[7:0]
PHY1 MIIRegister
Basic Status
[15:8]
PHY1 PHYID
Low
[7:0]
PHY2 MIIRegister
Basic Status
[7:0]
PHY2 MIIRegister
Basic Status
[15:8]
PHY2 PHYID
Low
[7:0]
Digital Test
Control
[15:8]
Analog Test
Control 0
[7:0]
PHY1 PHYID
Low
[15:8]
PHY1 PHYID
High
[7:0]
PHY2 PHYID
Low
[15:8]
PHY2 PHYID
High
[7:0]
PHY2 LinkMD
Control/Status
[15:8]
Analog Test
Control 0
[15:8]
PHY1 PHYID
High
[15:8]
PHY2 PHYID
High
[15:8]
PHY2 Special
Control/Status
[15:8]
Analog Test
Control 1
[7:0]
Analog Test
Control 1
[15:8]
Analog Test
Control 2
[7:0]
PHY1 A.N.
Advertisement
[7:0]
PHY1 A.N.
Advertisement
[15:8]
PHY1 A.N.
Link Partner
Ability [7:0]
PHY2 A.N.
Advertisement
[7:0]
PHY2 A.N.
Advertisement
[15:8]
PHY2 A.N.
Link Partner
Ability [7:0]
Analog Test
Control 2
[15:8]
PHY1 A.N.
Link Partner
Ability [15:8]
PHY2 A.N.
Link Partner
Ability [15:8]
To
0x3
Bank 45
Digital Test
Status
[7:0]
Reserved
- 0x1
0x0
Bank Location
Analog Test
Status
[15:8]
PHY1 Special
Control/Status
[7:0]
PHY1 Special
Control/Status
[15:8]
PHY2 LinkMD
Control/Status
[7:0]
PHY2 Special
Control/Status
[7:0]
Reserved
Reserved
0xC
0xC
Reserved
- 0xD
0xD
0xC
To
0xF
0xE
Bank Select [7:0]
0xF
Bank Select [15:8]
0xE
- 0xF
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KSZ8842-16/32 MQL/MVL
Internal I/O Space Mapping (continued)
I/O Register Location
32-Bit
16-Bit
8-Bit
0x1
Port 1
Control 1
[15:8]
Port 2
Control 1
[15:8]
0x3
0x2
0x2
- 0x3
0x3
0x4
0x4
- 0x5
0x5
To
0x6
0x6
- 0x7
0x7
0x8
0x8
- 0x9
0x9
0x8
To
0xB
Bank 50
Port 1 PHY
Port 2
Special
Control 1
Control/Status, [7:0]
LinkMD [7:0]
To
0x7
Bank 49
Port 1
Control 1
[7:0]
0x0
0x4
Bank 48
0x0
- 0x1
0x0
Bank Location
Port 1 PHY
Special
Control/Status,
LinkMD [15:8]
Port 1
Port 1
Control 2
Control 4
[7:0]
[7:0]
Port 1
Port 1
Control 2
Control 4
[15:8]
[15:8]
Port 1 VID Port 1
Control
Status
[7:0]
[7:0]
Port 1 VID Port 1
Control
Status
[15:8]
[15:8]
Port 1
Control 3
[7:0]
Reserved
Port 1
Control 3
[15:8]
Port1 Ingress
Rate Control
[7:0]
Port1 Ingress
Rate Control
[15:8]
0xA
Port1 Egress
Rate Control
[7:0]
0xB
Port1 Egress
Rate Control
[15:8]
0xA
- 0xB
Reserved
Bank 51
Port 2 PHY
Host Port
Special
Control 1
Control/Status, [7:0]
LinkMD [7:0]
Port 1 PHY
Special
Control/Status,
LinkMD [15:8]
Port 2
Port 2
Control 2
Control 4
[7:0]
[7:0]
Port 2
Port 2
Control 2
Control 4
[15:8]
[15:8]
Port 2 VID Port 2
Control
Status
[7:0]
[7:0]
Port 2 VID Port 2
Control
Status
[15:8]
[15:8]
Port 2
Control 3
[7:0]
Reserved
Port 2
Control 3
[15:8]
Port2 Ingress
Rate Control
[7:0]
Reserved
Port2 Ingress
Rate Control
[15:8]
Port2 Egress
Rate Control
[7:0]
Reserved
Bank 52
Port2 Egress
Rate Control
[15:8]
Host Port
Control 1
[15:8]
Host Port
Control 2
[7:0]
Host Port
Control 2
[15:8]
Host
Port
VID Control
[7:0]
Bank 53
Bank 54
Bank 55
Reserved
Reserved
Reserved
Host
Port
VID Control
[15:8]
Host Port
Control 3
[7:0]
Host Port
Control 3
[15:8]
Host
Port
Ingress Rate
Control [7:0]
Host
Port
Ingress Rate
Control [15:8]
Reserved
Reserved
Host
Port
Egress Rate
Control [7:0]
Reserved
Host
Port
Egress Rate
Control [15:8]
Reserved
0xC
0xC
Reserved
- 0xD
0xD
0xC
To
0xF
0xE
Bank Select [7:0]
0xF
Bank Select [15:8]
0xE
- 0xF
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KSZ8842-16/32 MQL/MVL
Internal I/O Space Mapping (continued)
I/O Register Location
32-Bit
16-Bit
8-Bit
Bank Location
Bank 56
Bank 57
Bank 58
Bank 59
Bank 60
Bank 61
Bank 62
Bank 63
0x0
0x0
Reserved
- 0x1
0x1
0x0
To
0x3
0x2
0x2
Reserved
- 0x3
0x3
0x4
0x4
Reserved
- 0x5
0x5
0x4
To
0x7
0x6
0x6
Reserved
- 0x7
0x7
0x8
0x8
Reserved
- 0x9
0x9
0x8
To
0xB
0xA
0xA
Reserved
- 0xB
0xB
0xC
0xC
Reserved
- 0xD
0xD
0xC
To
0xF
0xE
Bank Select [7:0]
0xF
Bank Select [15:8]
0xE
- 0xF
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KSZ8842-16/32 MQL/MVL
Register Map: Switch & MAC/PHY
Do not write to bit values or to registers defined as Reserved. Manipulating reserved bits or registers causes
unpredictable and often fatal results. If the user wants to write to these reserved bits, the user has to read back these
reserved bits (RO or RW) first, then “OR” with the read value of the reserved bits and write back to these reserved bits.
Bit Type Definition
RO = Read only.
RW = Read/Write.
W1C = Write 1 to Clear (writing a one to this bit clears it).
Bank 0-63 Bank Select Register (0x0E): BSR (same location in all Banks)
The bank select register is used to select or to switch between different sets of register banks for I/O access.
There are a total of 64 banks available to select, including the built-in switch engine registers.
Bit
Default Value
R/W
Description
15-6
0x000
RO
Reserved
5-0
0x00
R/W
BSA Bank Select Address Bits
BSA bits select the I/O register bank in use.
This register is always accessible regardless of the register bank currently selected.
Notes:
The bank select register can be accessed as a doubleword (32-bit) at offset 0xC, as
a word (16-bit) at offset 0xE, or as a byte (8-bit) at offset 0xE.
A doubleword write to offset 0xC writes to the BANK Select Register but does not
write to registers 0xC and 0xD; it only writes to register 0xE.
Bank 0 Base Address Register (0x00): BAR
This register holds the base address for decoding a device access. Its value is loaded from the external EEPROM (0x0H)
upon a power-on reset if the EEPROM Enable (EEEN) pin is tied to High. Its value can also be modified after reset.
Writing to this register does not store the value into the EEPROM. When the EEEN pin is tied to Low, the default base
address is 0x0300.
Bit
Default Value
R/W
Description
15-8
0x03 if EEEN
is Low or, the
value from
EEPROM if
EEEN is High
RW
BARH Base Address High
0x0 if EEEN is
Low or, the
value from
EEPROM if
EEEN is High
RW
0x00
RO
7-5
4-0
November 2005
These bits are compared against the address on the bus ADDR[15:8] to determine the
BASE for the KSZ8842M registers.
BARL Base Address Low
These bits are compared against the address on the bus ADDR[7:5] to determine the
BASE for the KSZ8842M registers.
Reserved
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Bank 0 Bus Error Status Register (0x06): BESR
This register flags the different kinds of errors on the host bus.
Bit
Default Value
R/W
Description
15
0
RO
IBEC Illegal Byte Enable Combination
1: illegal byte enable combination occurs. The illegal combination value can be found
from bit 14 to bit 11.
0: legal byte enable combination.
Write 1 to clear.
14-11
-
RO
IBECV Illegal Byte Enable Combination Value
Bit 14: byte enable 3.
Bit 13: byte enable 2.
Bit 12: byte enable 1.
Bit 11: byte enable 0.
This value is valid only when bit 15 is set to 1.
10
0
RO
SSAXFER Simultaneous Synchronous and Asnychronous Transfers
1: Synchronous and Asnychronous Transfers occur simultaneously.
0: normal.
Write 1 to clear.
9-0
0x000
RO
Reserved
Bank 0 Bus Burst Length Register (0x08): BBLR
Before the burst can be sent, the burst length needs to be programmed.
Bit
Default Value
R/W
Description
15
0
RO
Reserved
14-12
0x0
RW
BRL Burst Length (for burst read and write)
000: single.
011: fixed burst read length of 4.
101: fixed burst read length of 8.
111: fixed burst read length of 16.
11-0
0x000
RO
Reserved
Bank 1: Reserved
Except Bank Select Register (0xE).
Bank 2 Host MAC Address Register Low (0x00): MARL
This register along with the other two Host MAC address registers are loaded starting at word location 0x1 of the
EEPROM upon hardware reset. The software driver can modify the register, but it will not modify the original Host MAC
address value in the EEPROM. These six bytes of Host MAC address in external EEPROM are loaded to these three
registers as mapping below:
MARL[15:0] = EEPROM 0x1(MAC Byte 2 and 1)
MARM[15:0] = EEPROM 0x2(MAC Byte 4 and 3)
MARH[15:0] = EEPROM 0x3(MAC Byte 6 and 5)
The Host MAC address is used to define the individual destination address that the KSZ8842M responds to when
receiving frames. Network addresses are generally expressed in the form of 01:23:45:67:89:AB, where the bytes are
received from left to right, and the bits within each byte are received from right to left (LSB to MSB). For example, the
actual transmitted and received bits are on the order of 10000000 11000100 10100010 11100110 10010001 11010101.
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These three registers value for Host MAC address 01:23:45:67:89:AB will be held as below:
MARL[15:0] = 0x89AB
MARM[15:0] = 0x4567
MARH[15:0] = 0x0123
The following table shows the register bit fields.
Bit
Default Value
R/W
Description
15-0
-
RW
MARL MAC Address Low
The least significant word of the MAC address.
Bank 2 Host MAC Address Register Middle (0x02): MARM
The middle word of Host MAC address.
The following table shows the register bit fields.
Bit
Default Value
R/W
Description
15-0
-
RW
MARM MAC Address Middle
The middle word of the MAC address.
Bank 2 Host MAC Address Register High (0x04): MARH
The high word of Host MAC address.
The following table shows the register bit fields.
Bit
Default Value
R/W
Description
15-0
-
RW
MARH MAC Address High
The Most significant word of the MAC address.
Bank 3 On-Chip Bus Control Register (0x00): OBCR
This register controls the on-chip bus speed for the KSZ8842M. It is used for power management when the external host
CPU is running at a slow frequency. The default of the on-chip bus speed is 125 MHz without EEPROM. When the
external host CPU is running at a higher clock rate, the on-chip bus should be adjusted for the best performance.
Bit
Default Value
R/W
Description
15-2
-
RO
Reserved
1-0
0x0
RW
OBSC On-Chip Bus Speed Control
00: 125MHz.
01: 62.5MHz.
10: 41.66MHz.
11: 25MHz.
Note: When external EEPROM is enabled, the bit 1 in Configparm word (0x6H) is
used to contol this speed as below:
Bit 1 = 0 , this value will be 00 for 125 MHz.
Bit 1 = 1 , this value will be 11 for 25 MHz.
(User still can write these two bits to change speed after EEPROM data loaded)
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Bank 3 EEPROM Control Register (0x02): EEPCR
To support an external EEPROM, tie the EEPROM Enable (EEEN) pin to High; otherwise, tie it to Low. If an external
EEPROM is not used, the default chip Base Address (0x300), and the software programs the host MAC address. If an
EEPROM is used in the design (EEPROM Enable pin to High), the chip Base Address and host MAC address are loaded
from the EEPROM immediately after reset. The KSZ8842M allows the software to access (read and write) the EEPROM
directly; that is, the EEPROM access timing can be fully controlled by the software if the EEPROM Software Access bit is
set.
Bit
Default Value
R/W
Description
15-5
-
RO
Reserved
4
0
RW
EESA EEPROM Software Access
1: enable software to access EEPROM through bit 3 to bit 0.
0: disable software to access EEPROM.
3
-
RO
EECB EEPROM Status Bit
Data Receive from EEPROM. This bit directly reads the EEDI pin.
2-0
0x0
RW
EECB EEPROM Control Bits
Bit 2: Data Transmit to EEPROM. This bit directly controls the device’s EEDO pin.
Bit 1: Serial Clock. This bit directly controls the device’s EESK pin.
Bit 0: Chip Select for EEPROM. This bit directly controls the device’s EECS pin.
Bank 3 Memory BIST INFO Register (0x04): MBIR
Bit
Default Value
R/W
Description
15-13
0x0
RO
Reserved
12
-
RO
TXMBF TX Memory Bist Finish
11
-
RO
When set, it indicates the Memory Built In Self Test completion for the TX Memory.
TXMBFA TX Memory Bist Fail
When set, it indicates the Memory Built In Self Test has failed.
10-5
-
RO
Reserved
4
-
RO
RXMBF RX Memory Bist Finish
When set, it indicates the Memory Built In Self Test completion for the RX Memory.
3
-
RO
RXMBFA RX Memory Bist Fail
When set, it indicates the Memory Built In Self Test has failed.
2-0
-
RO
Reserved
Bank 3 Global Reset Register (0x06): GRR
This register controls the global reset function with information programmed by the CPU.
Bit
Default Value
R/W
Description
15-1
0x0000
RO
Reserved
0
0
RW
Global Soft Reset
1: software reset is active.
0: software reset is inactive.
Software reset will affect PHY, MAC, QMU, DMA, and the switch core, only the BIU
(base address registers) remains unaffected by a software reset.
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Bank 3 Bus Configuration Register (0x08): BCFG
This register is a read-only register. The bit 0 is automatically downloaded from bit 0 Configparm word of EEPROM , if pin
EEEN is high (enabled EEPROM)
Bit
Default Value
R/W
Description
15-1
0x0000
RO
Reserved
0
-
RO
Bus Configuration (only for KSZ8842-16 device)
1: bus width is 16 bits.
0: bus width is 8 bits.
(this bit is only avaiable when EEPROM is enabled)
Banks 4 – 15: Reserved
Except Bank Select Register (0xE).
Bank 16 Transmit Control Register (0x00): TXCR
This register holds control information programmed by the CPU to control the QMU transmit module function.
Bit
Default Value
R/W
Description
15
-
RO
Reserved
14
0x0
RW
Reserved
13
0x0
RW
Reserved
12-4
-
RO
Reserved
3
0x0
RW
TXFCE Transmit Flow Control Enable
When this bit is set, the QMU sends flow control pause frames from the host port if the
RX FIFO has reached its threshold.
Note: the SGCR3[5] in Bank 32 also needs to be enabled.
2
0x0
RW
TXPE Transmit Padding Enable
When this bit is set, the KSZ8842M automatically adds a padding field to a packet
shorter than 64 bytes.
Note: Setting this bit requires enabling the ADD CRC feature to avoid CRC errors for
the transmit packet.
1
0x0
RW
TXCE Transmit CRC Enable
When this bit is set, the KSZ8842M automatically adds a CRC checksum field to the
end of a transmit frame.
0
0x0
RW
TXE Transmit Enable
When this bit is set, the transmit module is enabled and placed in a running state.
When reset, the transmit process is placed in the stopped state after the transmission
of the current frame is completed.
Bank 16 Transmit Status Register (0x02): TXSR
This register keeps the status of the last transmitted frame.
Bit
15-6
Default Value
0x000
R/W
RO
Description
Reserved
5-0
-
RO
TXFID Transmit Frame ID
This field identifies the transmitted frame. All of the transmit status information in this
register belongs to the frame with this ID.
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Bank 16 Receive Control Register (0x04): RXCR
This register holds control information programmed by the CPU to control the receive function.
Bit
Default Value
R/W
Description
15-11
-
RO
Reserved
10
0x0
RW
RXFCE Receive Flow Control Enable
When this bit is set, the KSZ8842M will acknowledge a PAUSE frame from the receive
interface; i.e., the outgoing packets are pending in the transmit buffer until the PAUSE
frame control timer expires. When this bit is cleared, flow control is not enabled.
9
0x0
RW
RXEFE Receive Error Frame Enable
When this bit is set, CRC error frames are allowed to be received into the RX queue.
When reset, all CRC error frames are discarded.
8
-
RO
Reserved
7
0x0
RW
RXBE Receive Broadcast Enable
When this bit is set, the RX module receives all the broadcast frames.
6
0x0
RW
RXME Receive Multicast Enable
When this bit is set, the RX module receives all the multicast frames (including
broadcast frames).
5
0x0
RW
RXUE Receive Unicast
When this bit is set, the RX module receives unicast frames that match the 48-bit
Station MAC address of the module.
4
0x0
RW
RXRA Receive All
When this bit is set, the KSZ8842M receives all incoming frames, regardless of the
frame’s destination address.
3
0x0
RW
RXSCE Receive Strip CRC
When this bit is set, the KSZ8842M strips the CRC on the received frames. Once
cleared, the CRC is stored in memory following the packet.
2
0x0
RW
QMU Receive Multicast Hash-Table Enable
When this bit is set, this bit enables the RX function to receive multicast frames that
pass the CRC Hash filtering mechanism.
1
-
RO
Reserved
0
0x0
RW
RXE Receive Enable
When this bit is set, the RX block is enabled and placed in a running state. When
reset, the receive process is placed in the stopped state upon completing reception of
the current frame.
Bank 16 TXQ Memory Information Register (0x08): TXMIR
This register indicates the amount of free memory available in the TXQ of the QMU module.
Bit
Default Value
R/W
Description
15-13
-
RO
Reserved
12-0
-
RO
TXMA Transmit Memory Available
The amount of memory available is represented in units of byte. The TXQ memory is
used for both frame payload, control word. There is total 4096 bytes in TXQ.
Note: Software must be written to ensure that there is enough memory for the next
transmit frame including control information before transmit data is written to the TXQ.
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Bank 16 RXQ Memory Information Register (0x0A): RXMIR
This register indicates the amount of receive data available in the RXQ of the QMU module.
Bit
Default Value
R/W
Description
15-13
12-0
-
RO
RO
Reserved
RXMA Receive Packet Data Available
The amount of Receive packet data available is represented in units of byte. The RXQ
memory is used for both frame payload, status word. There is total 4096 bytes in RXQ.
This counter will update after a complete packet is received and also issues an
interrupt when receive interrupt enable IER[13] in Bank 18 is set.
Note: Software must be written to empty the RXQ memory to allow for the new RX
frame. If this is not done, the frame may be discarded as a result of insufficient RXQ
memory.
Bank 17 TXQ Command Register (0x00): TXQCR
This register is programmed by the Host CPU to issue a transmit command to the TXQ. The present transmit frame in the
TXQ memory is queued for transmit.
Bit
Default Value
R/W
Description
15-1
0
0x0
RO
RW
Reserved
TXETF Enqueue TX Frame
When this bit is set as 1, the current TX frame prepared in the TX buffer is queued for
transmit.
Note: This bit is self-clearing after the frame is finished transmitting. The software
should wait for the bit to be cleared before setting up another new TX frame.
Bank 17 RXQ Command Register (0x02): RXQCR
This register is programmed by the Host CPU to issue release command to the RXQ. The current frame in the RXQ frame
buffer is read out by the host and the memory space is released.
Bit
Default Value
R/W
Description
15-1
0
0x0
RO
RW
Reserved Do not write to this register.
RXRRF Release RX Frame
When this bit is set as 1, the current RX frame buffer is released.
Note: This bit is self-clearing after the frame memory is released. The software should
wait for the bit to be cleared before processing new RX frames.
Bank 17 TX Frame Data Pointer Register (0x04): TXFDPR
The value of this register determines the address to be accessed within the TXQ frame buffer. When the AUTO increment
is set, It will automatically increment the pointer value on Write accesses to the data register.
The counter is incremented by one for every byte access, by two for every word access, and by four for every double
word access.
Bit
Default Value
R/W
Description
15
14
0x0
RO
RW
13-11
10-0
0x0
RO
RW
Reserved
TXFPAI TX Frame Data Pointer Auto Increment
When this bit is set, the TX Frame data pointer register increments automatically on
accesses to the data register. The increment is by one for every byte access, by two
for every word access, and by four for every doubleword access.
When this bit is reset, the TX frame data pointer is manually controlled by user to
access the TX frame location.
Reserved
TXFP TX Frame Pointer
TX Frame Pointer index to the Frame Data register for access.
This field reset to next available TX frame location when the TX Frame Data has been
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enqueued through the TXQ command register.
Bank 17 RX Frame Data Pointer Register (0x06): RXFDPR
The value of this register determines the address to be accessed within the RXQ frame buffer. When the Auto Increment
is set, it will automatically increment the RXQ Pointer on read accesses to the data register.
The counter is incremented is by one for every byte access, by two for every word access, and by four for every double
word access.
Bit
Default Value
R/W
Description
15
-
RO
Reserved
14
0x0
RW
RXFPAI RX Frame Pointer Auto Increment
When this bit is set, the RXQ Address register increments automatically on accesses
to the data register. The increment is by one for every byte access, by two for every
word access, and by four for every double word access.
When this bit is reset, the RX frame data pointer is manually controlled by user to
access the RX frame location.
13-11
-
RO
Reserved
10-0
0x0
RW
RXFP RX Frame Pointer
RX Frame data pointer index to the Data register for access.
This field reset to next available RX frame location when RX Frame release command
is issued (through the RXQ command register).
Bank 17 QMU Data Register Low (0x08): QDRL
This register QDRL(0x08-0x09) contains the Low data word presently addressed by the pointer register. Reading maps
from the RXQ, and writing maps to the TXQ.
Bit
Default Value
R/W
Description
15-0
-
RW
QDRL Queue Data Register Low
This register is mapped into two uni-directional buffers for 16-bit buses, and one unidirectional buffer for 32-bit buses, (TXQ when Write, RXQ when Read) that allow
moving words to and from the KSZ8842M regardless of whether the pointer is even,
odd, or Dword aligned. Byte, word, and Dword access can be mixed on the fly in any
order. This register along with DQRH is mapped into two consecutive word locations
for 16-bit buses, or one word location for 32-bit buses, to facilitate Dword move
operations.
Bank 17 QMU Data Register High (0x0A): QDRH
This register QDRH(0x0A-0x0B) contains the High data word presently addressed by the pointer register. Reading maps
from the RXQ, and writing maps to the TXQ.
Bit
15-0
Default Value
-
R/W
Description
RW
QDRL Queue Data Register High
This register is mapped into two uni-directional buffers for 16-bit buses, and one unidirectional buffer for 32-bit buses, (TXQ when Write, RXQ when Read) that allow
moving words to and from the KSZ8842M regardless of whether the pointer is even,
odd, or dword aligned. Byte, word, and Dword access can be mixed on the fly in any
order. This register along with DQRL is mapped into two consecutive word locations
for 16-bit buses, or one word location for 32-bit buses, to facilitate Dword move
operations.
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Bank 18 Interrupt Enable Register (0x00): IER
This register enables the interrupts from the QMU and other sources.
Bit
Default Value
R/W
Description
15
0x0
RW
LCIE Link Change Interrupt Enable
When this bit is set, the link change interrupt is enabled.
When this bit is reset, the link change interrupt is disabled.
14
0x0
RW
TXIE Transmit Interrupt Enable
When this bit is set, the transmit interrupt is enabled.
When this bit is reset, the transmit interrupt is disabled.
13
0x0
RW
RXIE Receive Interrupt Enable
When this bit is set, the receive interrupt is enabled.
When this bit is reset, the receive interrupt is disabled.
12
0x0
RW
Reserved
11
0x0
RW
RXOIE Receive Overrun Interrupt Enable
When this bit is set, the Receive Overrun interrupt is enabled.
When this bit is reset, the Receive Overrun interrupt is disabled.
10
0x0
RW
Reserved
9
0x0
RW
TXPSIE Transmit Process Stopped Interrupt Enable
When this bit is set, the Transmit Process Stopped interrupt is enabled.
When this bit is reset, the Transmit Process Stopped interrupt is disabled.
8
0x0
RW
RXPSIE Receive Process Stopped Interrupt Enable
When this bit is set, the Receive Process Stopped interrupt is enabled.
When this bit is reset, the Receive Process Stopped interrupt is disabled.
7
0x0
RW
RXEFIE Receive Error Frame Interrupt Enable
When this bit is set, the Receive error frame interrupt is enabled.
When this bit is reset, the Receive error frame interrupt is disabled.
6-0
-
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RO
Reserved
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Bank 18 Interrupt Status Register (0x02): ISR
This register contains the status bits for all QMU and other interrupt sources.
When the corresponding enable bit is set, it causes the interrupt pin to be asserted.
This register is usually read by the host CPU and device drivers during interrupt service routine or polling. The register bits
are not cleared when read. The user has to write “1” to clear
Bit
Default Value
R/W
Description
15
0x0
RO
(W1C)
LCIS Link Change Interrupt Status
When this bit is set, it indicates that the link status has changed from link up to link
down, or link down to link up.
This edge-triggered interrupt status is cleared by writing 1 to this bit.
14
0x0
RO
(W1C)
TXIS Transmit Status
When this bit is set, it indicates that the TXQ MAC has transmitted at least a frame on
the MAC interface and the QMU TXQ is ready for new frames from the host.
This edge-triggered interrupt status is cleared by writing 1 to this bit.
13
0x0
RO
(W1C)
RXIS Receive Interrupt Status
When this bit is set, it indicates that the QMU RXQ has received a frame from the
MAC interface and the frame is ready for the host CPU to process.
This edge-triggered interrupt status is cleared by writing 1 to this bit.
12
11
0x0
RO
Reserved
0x0
RO
(W1C)
RXOIS Receive Overrun Interrupt Status
When this bit is set, it indicates that the Receive Overrun status has occurred.
This edge-triggered interrupt status is cleared by writing 1 to this bit.
10
0x0
RO
Reserved
9
0x1
RO
(W1C)
TXPSIE Transmit Process Stopped Status
When this bit is set, it indicates that the Transmit Process has stopped.
This edge-triggered interrupt status is cleared by writing 1 to this bit.
8
0x1
RO
(W1C)
RXPSIE Receive Process Stopped Status
When this bit is set, it indicates that the Receive Process has stopped.
This edge-triggered interrupt status is cleared by writing 1 to this bit.
7
0x0
RO
(W1C)
RXEFIE Receive Error Frame Interrupt Status
When this bit is set, it indicates that the Receive error frame status has occurred.
This edge-triggered interrupt status is cleared by writing 1 to this bit.
6-0
-
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RO
Reserved
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Bank 18 Receive Status Register (0x04): RXSR
This register indicates the status of the current received frame and mirrors the Receive Status word of the Receive Frame
in the RXQ.
Bit
Default Value
R/W
Description
15
-
RO
RXFV Receive Frame Valid
When set, it indicates that the present frame in the receive packet memory is valid.
The status information currently in this location is also valid.
When clear, it indicates that there is either no pending receive frame or that the
current frame is still in the process of receiving.
14-9
-
RO
Reserved
8
-
RO
RXSPN Receive Source Port Number
When set, this field indicates the source port where the packet was received.
Valid ports are either port 1 or port 2.
7
-
RO
RXBF Receive Broadcast Frame
When set, it indicates that this frame has a broadcast address.
6
-
RO
RXMF Receive Multicast Frame
When set, it indicates that this frame has a multicast address (including the broadcast
address).
5
-
RO
RXUF Receive Unicast Frame
When set, it indicates that this frame has a unicast address.
4
-
RO
Reserved
3
-
RO
RXFT Receive Frame Type
When set, it indicates that the frame is an Ethernet-type frame (frame length is greater
than 1500 bytes).
When clear, it indicate that the frame is an IEEE 802.3 frame.
This bit is not valid for runt frames.
2
-
RO
RXTL Receive Frame Too Long
When set, it indicates that the frame length exceeds the maximum size of 1916 bytes.
Frames that are too long are passed to the host only if the pass bad frame bit is set
(bit 9 in RXCR register)
Note: Frame too long is only a frame length indication and does not cause any frame
truncation.
1
-
RO
RXRF Receive Runt Frame
When set, it indicates that a frame was damaged by a collision or premature
termination before the collision window has passed. Runt frames are passed to the
host only if the pass bad frame bit is set (bit 9 in RXCR register).
0
-
RO
RXCE Receive CRC Error
When set, it indicates that a CRC error has occurred on the current received frame. A
CRC error frame is passed to the host only if the pass bad frame bit is set (bit 9 in
RXCR register).
Bank 18 Receive Byte Counter Register (0x06): RXBC
This register indicates the status of the current received frame and mirrors the Receive Byte Count word of the Receive
Frame in the RXQ.
Bit
Default Value
R/W
Description
15-11
-
RO
Reserved
10-0
-
RO
RXBC Receive Byte Count
Receive Byte Count.
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Bank 19 Multicast Table Register 0 (0x00): MTR0
The 64-bit multicast table is used for group address filtering. This value is defined as the six most significant bits from
CRC circuit calculation result that is based on 48-bit of DA input. The two most significant bits select one of the four
registers to be used, while the others determine which bit within the register.
Multicast table register 0.
Bit
Default Value
R/W
Description
15-0
0x0000
RW
MTR0 Multicast Table 0
When the appropriate bit is set, if the packet received with DA matches the CRC, the
hashing function is received without being filtered.
When the appropriate bit is cleared, the packet will drop.
Note: When the receive all (RXRA) or receive multicast (RXRM) bit is set in the RXCR,
all multicast addresses are received regardless of the multicast table value.
Bank 19 Multicast Table Register 1 (0x02): MTR1
Multicast table register 1.
Bit
Default Value
R/W
Description
15-0
0x0000
RW
MTR0 Multicast Table 1
When the appropriate bit is set, if the packet received with DA matches the CRC, the
hashing function is received without being filtered.
When the appropriate bit is cleared, the packet will drop.
Note: When the receive all (RXRA) or receive multicast (RXRM) bit is set in the RXCR,
all multicast addresses are received regardless of the multicast table value.
Bank 19 Multicast Table Register 2 (0x04): MTR2
Multicast table register 2.
Bit
Default Value
R/W
Description
15-0
0x0000
RW
MTR0 Multicast Table 2
When the appropriate bit is set, if the packet received with DA matches the CRC, the
hashing function is received without being filtered.
When the appropriate bit is cleared, the packet will drop.
Note: When the receive all (RXRA) or receive multicast (RXRM) bit is set in the RXCR,
all multicast addresses are received regardless of the multicast table value.
Bank 19 Multicast Table Register 3 (0x06): MTR3
Multicast table register 3.
Bit
Default Value
R/W
Description
15-0
0x0000
RW
MTR0 Multicast Table 3
When the appropriate bit is set, if the packet received with DA matches the CRC, the
hashing function is received without being filtered.
When the appropriate bit is cleared, the packet will drop.
Note: When the receive all (RXRA) or receive multicast (RXRM) bit is set in the RXCR,
all multicast addresses are received regardless of the multicast table value.
Banks 20 – 31: Reserved
Except Bank Select Register (0xE).
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Bank 32 Switch ID and Enable Register (0x00): SIDER
This register contains the switch ID and the switch enable control.
Bit
Default
R/W
Description
15-8
0x88
RO
Family ID
Chip family ID
Chip ID
7-4
0x0
RO
3-1
0x0
RO
Revision ID
0
0
RW
Start Switch
0x0 is assigned to KSZ8842M
1 = start the chip.
0 = switch is disabled.
Bank 32 Switch Global Control Register 1 (0x02): SGCR1
This register contains the global control for the switch function.
Bit
Default
R/W
Description
15
0
RW
Pass All Frames
1 = switch all packets including bad ones. Used solely for debugging purposes. Works
in conjunction with Sniffer mode only.
14
0
RW
Reserved
13
1
RW
IEEE 802.3x Transmit Direction Flow Control Enable
1 = enables transmit direction flow control feature.
0 = will not enable transmit direction flow control feature. The switch will not generate
any flow control packets.
12
1
RW
IEEE 802.3x Receive Direction Flow Control Enable
1 = enables receive direction flow control feature.
0 = will not enable receive direction flow control feature. The switch will not react to
any received flow control packets.
11
0
RW
Frame Length Field Check
1 = checks frame length field in the IEEE packets. If the actual length does not match,
the packet will be dropped (for Length/Type field < 1500).
10
1
RW
Aging Enable
1 = enable age function in the chip.
0 = disable age function in the chip.
9
0
RW
Fast Age Enable
1 = turn on fast age (800us).
8
0
RW
Aggressive Back-Off Enable
1 = enable more aggressive back off algorithm in half-duplex mode to enhance
performance. This is not an IEEE standard.
7-4
-
RW
Reserved
3
0x0
RW
Pass Flow Control Packet
1 = switch will not filter 802.1x “flow control” packets.
2-1
-
RW
Reserved
0
0
RW
Link Change Age
1 = link change from “link” to “no link” will cause fast aging (<800us) 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.
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Bank 32 Switch Global Control Register 2 (0x04): SGCR2
This register contains the global control for the switch function.
Bit
Default
R/W
Description
15
0
RW
802.1Q VLAN Enable
1 = 802.1Q VLAN mode is turned on. VLAN table must be set up before the operation.
0 = 802.1Q VLAN is disabled.
14
0
RW
IGMP Snoop Enable On Switch Host port
1 = IGMP snoop is enabled.
All the IGMP packets are forwarded to the Switch host port.
0 = IGMP snoop is disabled.
13
0
RW
12
0
RW
Ipv6 MLD Snooping Enable
1 = enable IPv6 MLD snooping
Ipv6 MLD Snooping Option
1 = enable IPv6 MLD snooping option
11
0
RW
Priority Scheme Select
0 = always TX higher priority packets first.
1 = Weighted Fair Queueing enabled. When all four queues have packets waiting to
transmit, the bandwidth allocation is q3:q2:q1:a0 = 8:4:2:1.
If any queues are empty, the highest non-empty queue gets one more weighting. For
example, if q2 is empty, q3:q1:q0 becomes (8+1): 0:2:1.
10-9
0x0
RW
Reserved
8
0
RW
Sniff Mode Select
1 =performs RX and TX sniff (both the source port and destination port need to
match).
0 = performs RX or TX sniff (either the source port or destination port needs to match).
This is the mode used to implement RX only sniff.
7
1
RW
Unicast Port-VLAN Mismatch Discard
1 = no packets can cross the VLAN boundary.
0 = unicast packets (excluding unknown/multicast/broadcast) can cross the VLAN
boundary.
6
1
RW
Multicast Storm Protection Disable
1 = “Broadcast Storm Protection” does not include multicast packets. Only DA =
FFFFFFFFFFFF packets are regulated.
0 = “Broadcast Storm Protection” includes DA = FFFFFFFFFFFF and DA[40] = 1
packets.
5
1
RW
Back Pressure Mode
1 = carrier sense-based Back Pressure is selected.
0 = collision-based Back Pressure is selected.
4
1
RW
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 prevents 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 is flow controlled. This may not be “fair” to the
flow control port.
3
0
November 2005
RW
No Excessive Collision Drop
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Bit
Default
KSZ8842-16/32 MQL/MVL
R/W
Description
1 = the switch does not drop packets when 16 or more collisions occur.
0 = the switch drops packets when 16 or more collisions occur.
2
0
RW
Huge Packet Support
1 = accepts packet sizes up to 1916 bytes (inclusive). This bit setting overrides setting
from bit 1 of the same register.
0 = the max packet size is determined by bit 1 of this register.
1
0
RW
Legal Maximum Packet Size Check Enable
0 = accepts packet sizes up to 1536 bytes (inclusive).
1 = 1522 bytes for tagged packets, 1518 bytes for untagged packets. Any packets
larger than the specified value are dropped.
0
1
RW
Priority Buffer Reserve
1 = each port is pre-allocated 48 buffers, used exclusively for high priority (q3, q2, and
q1) packets. Effective only when the multiple queue feature is turned on.
0 = each port is pre-allocated 48 buffers used for all priority packets (q3, q2,q1, and
q0).
Bank 32 Switch Global Control Register 3 (0x06): SGCR3
This register contains the global control for the switch function.
Bit
Default
R/W
Description
15-8
0x63
RW
Broadcast Storm Protection Rate Bit [7:0]
These bits, along with SGCR3[2:0], determine how many 64-byte blocks of packet
data are allowed on an input port in a preset period. The period is 67ms for 100BT or
670ms for 10BT. The default is 1%.
7
0
RW
Repeater Mode (Note 1)
1 = enable repeater mode.
0 = normal mode.
The switch supports only half duplex , 100BT in repeater mode.
6
0
RW
5
0
RW
4
0
RW
Switch Host Half-Duplex Mode
The KSZ8842M supports only half-duplex 100-BaseT throughput in repeater mode.
1 = enable host port interface half-duplex mode, this bit must be set for repeater mode
0 = enable host port interface full-duplex mode..
Switch Flow Control Enable
1 = enable full-duplex flow control on Switch Host port.
0 = disable full-duplex flow control on Switch Host port
Reserved
3
0
RW
Null VID Replacement
1 = replaces NULL VID with port VID(12 bits).
0 = no replacement for NULL VID.
2-0
0x0
RW
Broadcast Storm Protection Rate Bit [10:8]
These bits, along with SGCR3[15:8] determine how many 64-byte blocks of packet
data are allowed on an input port in a preset period. The period is 67ms for 100BT or
670ms for 10BT. The default is 1%.
Rate: 148,800 frames/sec * 67 ms/interval * 1% = 99 frames/interval (approx.) = 0x63.
Note 1: User has to set bit 13 (100Mbps), bit 12 (auto-negotiation disabled) and bit 8 (half duplex) in both P1MBCR and
P2MBCR registers for repeater mode.
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Bank 32 Switch Global Control Register 4 (0x08): SGCR4
This register contains the global control for the switch function.
Bit
Default
R/W
Description
15-0
0x2400
RW
Reserved
Bank 32 Switch Global Control Register 5 (0x0A): SGCR5
This register contains the global control for the switch function.
Bit
Default
R/W
Description
15
0
RW
LEDSEL1
14-12
0x0
RW
Reserved
11-10
0x2
RW
Reserved
9
0
RW
LEDSEL0
See the description in bit 9.
These two bits, LEDSEL1 and LEDSEL0, are used to select LED mode.
Port n LED indicators, (where n = 1 for port 1 and n =2 for port 2) defined as below:
PnLED3
PnLED2
PnLED1
PnLED0
[LEDSEL1, LEDSEL0]
[0, 0]
[0, 1]
----------LINK/ACT
100LINK/ACT
FULL_DPX/COL
10LINK/ACT
SPEED
FULL_DPX
PnLED3
PnLED2
PnLED1
PnLED0
[LEDSEL1, LEDSEL0]
[1, 0]
[1, 1]
ACT
-----LINK
-----FULL_DPX/COL
-----SPEED
------
For repeater mode:
P1LED3; P2LED3
P1LED2; P2LED2
P1LED1; P2LED1
P1LED0; P2LED0
8
0
RW
Reserved
7-0
0x35
RW
Reserved
November 2005
[LEDSEL1, LEDSEL0]
[0, 0]
[0, 1] [1, 0] [1, 1]
RPT_COL; RPT_ACT
-----RPT_LINK3/RX; RPT_ERR3 -----RPT_LINK2/RX; RPT_ERR2 -----RPT_LINK1/RX; RPT_ERR1 ------
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Bank 33 Switch Global Control Register 6 (0x00): SGCR6
Bit
Default
R/W
Description
15-14
0x3
R/W
Tag_0x7
IEEE 802.1p mapping. The value in this field is used as the frame’s priority when its
IEEE Tag has a value of 0x7.
13-12
0x3
R/W
Tag_0x6
IEEE 802.1p mapping. The value in this field is used as the frame’s priority when its
IEEE Tag has a value of 0x6.
11-10
0x2
R/W
Tag_0x5
IEEE 802.1p mapping. The value in this field is used as the frame’s priority when its
IEEE Tag has a value of 0x5.
9-8
0x2
R/W
Tag_0x4
IEEE 802.1p mapping. The value in this field is used as the frame’s priority when its
IEEE Tag has a value of 0x4.
7-6
0x1
R/W
Tag_0x3
IEEE 802.1p mapping. The value in this field is used as the frame’s priority when its
IEEE Tag has a value of 0x3.
5-4
0x1
R/W
Tag_0x2
IEEE 802.1p mapping. The value in this field is used as the frame’s priority when its
IEEE Tag has a value of 0x2.
3-2
0x0
R/W
Tag_0x1
IEEE 802.1p mapping. The value in this field is used as the frame’s priority when its
IEEE Tag has a value of 0x1.
1-0
0x0
R/W
Tag_0x0
IEEE 802.1p mapping. The value in this field is used as the frame’s priority when its
IEEE Tag has a value of 0x0.
Bank 33 Switch Global Control Register 7 (0x02): SGCR7
Bit
Default
R/W
Description
15-8
0x00
R/W
Reserved
7
0
R/W
Unknown Default Port Enable
Send packets with unknown destination address to specified ports in bits [2:0].
1 = enable to send unknown DA packet
6-3
-
R/W
Reserved
2-0
0x7
R/W
Unknown Packet Default Port(s)
Specify which ports to send packets with unknown destination addresses. Feature is
enabled by bit [7].
Bit 2 for the host port, bit 1 for port 2, and bit 0 for port 1
Banks 34 – 38: Reserved
Except Bank Select Register (0xE)
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Bank 39 MAC Address Register 1 (0x00): MACAR1
This register contains the MAC address for the switch function. This MAC address is used for sending PAUSE frame.
Bit
Default
R/W
Description
15-0
0x0010
RW
MACA[47:32]
Specifies MAC address 1. This value has to be same as MARH in Bank2.
Bank 39 MAC Address Register 2 (0x02): MACAR2
This register contains the MAC address for the switch function. This MAC address is used for sending PAUSE frame.
Bit
Default
R/W
Description
15-0
0xA1FF
RW
MACA[31:16]
Specifies MAC address 2. This value has to be same as MARM in Bank2.
Bank 39 MAC Address Register 3 (0x04): MACAR3
This register contains the MAC address for the switch function. This MAC address is used for sending PAUSE frame.
Bit
Default
R/W
Description
15-0
0xFFFF
RW
MACA[15:0]
Specifies MAC address 3. This value has to be same as MARL in Bank2.
Bank 40 TOS Priority Control Register 1 (0x00): TOSR1
The Ipv4/Ipv6 ToS priority control registers implement a fully decoded,128-bit DSCP (Differentiated Services Code Point)
register used to determine priority from the 6-bit ToS (Type of Service) 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 bits in the DSCP register to determine the priority.
This register contains the ToS priority control for the switch function.
Bit
Default
R/W
Description
15-14
0
RW
13-12
0
R/W
11-10
0
R/W
9-8
0
R/W
7-6
0
R/W
5-4
0
R/W
3-2
0
R/W
1-0
0
R/W
DSCP[15:14]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x1c.
DSCP[13:12]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x18.
DSCP[11:10]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x14.
DSCP[9:8]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x10.
DSCP[7:6]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x0c.
DSCP[5:4]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x08.
DSCP[3:2]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x04.
DSCP[1:0]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x00.
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Bank 40 TOS Priority Control Register 2 (0x02): TOSR2
This register contains the TOS priority control for the switch function.
Bit
Default
R/W
Description
15-14
0
RW
13-12
0
R/W
11-10
0
R/W
9-8
0
R/W
7-6
0
R/W
5-4
0
R/W
3-2
0
R/W
1-0
0
R/W
DSCP[31:30]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x3c.
DSCP[29:28]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x38.
DSCP[27:26]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x34.
DSCP[25:24]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x30.
DSCP[23:22]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x2c.
DSCP[21:20]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x28.
DSCP[19:18]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x24.
DSCP[17:16]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x20.
Bank 40 TOS Priority Control Register 3 (0x04): TOSR3
This register contains the TOS priority control for the switch function.
Bit
Default
R/W
Description
15-14
0
RW
13-12
0
R/W
11-10
0
R/W
9-8
0
R/W
7-6
0
R/W
5-4
0
R/W
3-2
0
R/W
1-0
0
R/W
DSCP[47:46]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x5c.
DSCP[45:44]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x58.
DSCP[43:42]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x54.
DSCP[41:40]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x50.
DSCP[39:38]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x4c.
DSCP[37:36]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x48.
DSCP[35:34]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x44.
DSCP[33:32]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x40.
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Bank 40 TOS Priority Control Register 4 (0x06): TOSR4
This register contains the TOS priority control for the switch function.
Bit
Default
R/W
Description
15-14
0
RW
13-12
0
R/W
11-10
0
R/W
9-8
0
R/W
7-6
0
R/W
5-4
0
R/W
3-2
0
R/W
1-0
0
R/W
DSCP[63:62]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x7c.
DSCP[61:60]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x78.
DSCP[59:58]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x74.
DSCP[57:56]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x70.
DSCP[55:54]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x6c.
DSCP[53:52]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x68.
DSCP[51:50]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x64.
DSCP[49:48]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x60.
Bank 40 TOS Priority Control Register 5 (0x08): TOSR5
This register contains the TOS priority control for the switch function.
Bit
Default
R/W
Description
15-14
0
RW
13-12
0
R/W
11-10
0
R/W
9-8
0
R/W
7-6
0
R/W
5-4
0
R/W
3-2
0
R/W
1-0
0
R/W
DSCP[79:78]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x9c.
DSCP[77:76]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x98.
DSCP[75:74]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x94.
DSCP[73:72]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x90.
DSCP[71:70]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x8c.
DSCP[69:68]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x88.
DSCP[67:66]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x84.
DSCP[65:64]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0x80.
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Bank 40 TOS Priority Control Register 6 (0x0A): TOSR6
This register contains the TOS priority control for the switch function.
Bit
Default
R/W
Description
15-14
0
RW
13-12
0
R/W
11-10
0
R/W
9-8
0
R/W
7-6
0
R/W
5-4
0
R/W
3-2
0
R/W
1-0
0
R/W
DSCP[95:94]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xbc.
DSCP[93:92]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xb8.
DSCP[91:90]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xb4.
DSCP[89:88]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xb0.
DSCP[87:86]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xac.
DSCP[85:84]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xa8.
DSCP[83:82]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xa4.
DSCP[81:80]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xa0.
Bank 41 TOS Priority Control Register 7 (0x00): TOSR7
This register contains the TOS priority control for the switch function.
Bit
Default
R/W
Description
15-14
0
RW
13-12
0
R/W
11-10
0
R/W
9-8
0
R/W
7-6
0
R/W
5-4
0
R/W
3-2
0
R/W
1-0
0
R/W
DSCP[111:110]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xdc.
DSCP[109:108]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xd8.
DSCP[107:106]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xd4.
DSCP[105:104]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xd0.
DSCP[103:102]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xcc.
DSCP[101:100]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xc8.
DSCP[99:98]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xc4.
DSCP[97:96]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xc0.
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Bank 41 TOS Priority Control Register 8 (0x02): TOSR8
This register contains the TOS priority control for the switch function.
Bit
Default
R/W
Description
15-14
0
RW
13-12
0
R/W
11-10
0
R/W
9-8
0
R/W
7-6
0
R/W
5-4
0
R/W
3-2
0
R/W
1-0
0
R/W
DSCP[127:126]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xfc
DSCP[125:124]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xf8.
DSCP[123:122]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xf4.
DSCP[121:120]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xf0.
DSCP[119:118]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xec.
DSCP[117:116]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xe8.
DSCP[115:114]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xe4.
DSCP[113:112]
The value in this field is used as the frame’s priority when bits [7:2] of it IP
TOS/DiffServ/Traffic Class value is 0xe0.
Bank 42 Indirect Access Control Register (0x00): IACR
This register contains the indirect control for the switch function.
Bit
Default
R/W
Description
15-13
12
0x0
0
RW
RW
11-10
0x0
RW
9-0
0x000
RW
Reserved
Read High. Write Low
1 = read cycle.
0 = write cycle.
Table Select
00 = static MAC address table selected.
01 = VLAN table selected.
10 = dynamic address table selected.
11 = MIB counter selected.
Indirect Address
Bit 9-0 of indirect address.
Note: Write IACR triggers a command. Read or write access is determined by Register bit 12.
Bank 42 Indirect Access Data Register 1 (0x02): IADR1
This register contains the indirect data for the switch function.
Bit
Default
R/W
Description
15-8
7
0x00
0
RO
RO
Reserved
CPU Read Status
Only for dynamic and statistics counter reads.
1 = read is still in progress.
0 = read has completed.
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6-3
2-0
0x0
0x0
KSZ8842-16/32 MQL/MVL
RO
RO
Reserved
Indirect Data
Bit 66-64 of indirect data.
Bank 42 Indirect Access Data Register 2 (0x04): IADR2
This register contains the indirect data for the switch function.
Bit
Default
R/W
Description
15-0
0x0000
RW
Indirect Data
Bit 47-32 of indirect data.
Bank 42 Indirect Access Data Register 3 (0x06): IADR3
This register contains the indirect data for the switch function.
Bit
Default
R/W
Description
15-0
0x0000
RW
Indirect Data
Bit 63-48 of indirect data.
Bank 42 Indirect Access Data Register 4 (0x08): IADR4
This register contains the indirect data for the switch function.
Bit
Default
R/W
Description
15-0
0x0000
RW
Indirect Data
Bit 15-0 of indirect data.
Bank 42 Indirect Access Data Register 5 (0x0A): IADR5
This register contains the indirect data for the switch function.
Bit
Default
R/W
Description
15-0
0x0000
RW
Indirect Data
Bit 31-16 of indirect data.
Bank 43: Reserved
Except Bank Select Register (0xE)
Bank 44 Digital Testing Status Register (0x00): DTSR
This register contains the user defined register for the switch function.
Bit
Default
R/W
Description
15-3
0x0000
RO
Reserved
2-0
0x0
RO
Reserved
Bank 44 Analog Testing Status Register (0x02): ATSR
This register contains the user defined register for the switch function.
Bit
Default
R/W
Description
15-8
0x00
RO
Reserved
7-0
0x00
RO
Reserved
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Bank 44 Digital Testing Control Register (0x04): DTCR
This register contains the user defined register for the switch function.
Bit
Default
R/W
Description
15-8
7-0
0x00
0x3F
RO
RW
Reserved
Reserved
Bank 44 Analog Testing Control Register 0 (0x06): ATCR0
This register contains the user defined register for the switch function.
Bit
Default
R/W
Description
15-8
7-0
0x00
0x00
RO
RW
Reserved
Reserved
Bank 44 Analog Testing Control Register 1 (0x08): ATCR1
This register contains the user defined register for the switch function.
Bit
Default
R/W
Description
15-0
0x0000
RW
Reserved
Bank 44 Analog Testing Control Register 2 (0x0A): ATCR2
This register contains the user defined register for the switch function.
Bit
Default
R/W
Description
15-0
0x0000
RW
Reserved
Bank 45 PHY 1 MII-Register Basic Control Register (0x00): P1MBCR
This register contains Media Independent Interface (MII) register for switch port 1 as defined in the IEEE 802.3
specification.
Bit
Default
R/W
Description
15
0
RO
14
0
RW
13
0
RW
12
1
RW
11
0
RW
10
0
RO
9
0
RW
Soft reset
Not supported.
Far-End Loopback
1 = perform loopback as follows:
Start: RXP2/RXM2 (port 2)
Loop back: PMD/PMA of port 1’s PHY
End: TXP2/TXM2 (port 2)
0 = normal operation.
Force 100
1 = force 100Mbps if AN is disabled (bit 12)
0 = force 10Mbps if AN is disabled (bit 12)
AN Enable
1 = auto-negotiation enabled.
0 = auto-negotiation disabled.
Power-Down
1 = power-down.
0 = normal operation.
Isolate
Not supported.
Restart AN
1 = restart auto-negotiation.
0 = normal operation.
November 2005
Bit is same as:
77
Bank 49 0x02 bit 8
Bank 49 0x02 bit 6
Bank 49 0x02 bit 7
Bank 49 0x02 bit 11
Bank 49 0x02 bit 13
Rev. 1.4
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Bit
Default
R/W
Description
Bit is same as:
8
0
RW
Bank 49 0x02 bit 5
7
0
RO
6
5
0
1
RO
R/W
4
0
RW
3
0
RW
2
0
RW
1
0
RW
0
0
RW
Force Full Duplex
1 = force full duplex.
0 = force half duplex.
if AN is disabled (bit 12) or AN is enabled but
failed.
Collision test
Not supported.
Reserved.
HP_mdix
1 = HP Auto MDI-X mode.
0 = Micrel Auto MDI-X mode.
Force MDI-X
1 = force MDI-X.
0 = normal operation.
Disable MDI-X
1 = disable auto MDI-X.
0 = normal operation.
Disable Far-End-Fault
1 = disable far-end-fault detection.
0 = normal operation.
Disable Transmit
1 = disable transmit.
0 = normal operation.
Disable LED
1 = disable LED.
0 = normal operation.
Bank 49 0x04 bit 15
Bank 49 0x02 bit 9
Bank 49 0x02 bit 10
Bank 49 0x02 bit 12
Bank 49 0x02 bit 14
Bank 49 0x02 bit 15
Bank 45 PHY 1 MII-Register Basic Status Register (0x02): P1MBSR
This register contains the MII register status for the switch port 1 function.
Bit
Default
R/W
Description
15
0
RO
T4 Capable
Bit is same as:
1 = 100 BASE-T4 capable.
0 = not 100 BASE-T4 capable.
14
1
RO
100 Full Capable
1 = 100BASE-TX full-duplex capable.
0 = not 100BASE-TX full duplex capable.
13
1
RO
100 Half Capable
1 = 100BASE-TX half-duplex capable.
0 = not 100BASE-TX half-duplex capable.
12
1
RO
10 Full Capable
1 = 10BASE-T full-duplex capable.
0 = not 10BASE-T full-duplex capable.
11
1
RO
10 Half Capable
1 = 10BASE-T half-duplex capable.
0 = not 10BASE-T half-duplex capable.
10-7
0x0
RO
Reserved
6
0
RO
Preamble Suppressed
5
0
RO
Not supported.
AN Complete
Bank 49 0x04 bit 6
1 = auto-negotiation complete.
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Bit
Default
KSZ8842-16/32 MQL/MVL
R/W
Description
Bit is same as:
0 = auto-negotiation not completed.
4
0
RO
Far-End-Fault
Bank 49 0x04 bit 8
1 = far-end-fault detected.
0 = no far-end-fault detected.
3
1
RO
AN Capable
1 = auto-negotiation capable.
0 = not auto-negotiation capable.
2
0
RO
Link Status
Bank49 0x04 bit 5
1 = link is up.
0 = link is down.
1
0
RO
0
0
RO
Jabber test
Not supported.
Extended Capable
1 = extended register capable.
0 = not extended register capable.
Bank 45 PHY 1 PHYID Low Register (0x04): PHY1ILR
This register contains the PHY ID (low) for the switch port 1 function.
Bit
Default
R/W
Description
15-0
0x1430
RO
PHYID Low
Low order PHYID bits.
Bank 45 PHY 1 PHYID High Register (0x06): PHY1IHR
This register contains the PHY ID (high) for the switch port 1 function.
Bit
Default
R/W
Description
15-0
0x0022
RO
PHYID High
High order PHYID bits.
Bank 45 PHY 1 Auto-Negotiation Advertisement Register (0x08): P1ANAR
This register contains the auto-negotiation advertisement for the switch port 1 function.
Bit
Default
R/W
Description
15
0
RO
Next page
14
0
RO
Reserved
13
0
RO
Remote fault
Bit is same as:
Not supported.
Not supported.
12-11
0x0
RO
Reserved
10
1
RW
Pause (flow control capability)
Bank 49 0x02 bit 4
1 = advertise pause ability.
0 = do not advertise pause capability.
9
0
RW
Reserved
8
1
RW
Adv 100 Full
Bank49 0x02 bit 3
1 = advertise 100 full-duplex capable.
0 = do not advertise 100 full-duplex capability.
7
1
RW
Adv 100 Half
Bank49 0x02 bit 2
1= advertise 100 half-duplex capable.
0 = do not advertise 100 half-duplex capability.
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1
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RW
Adv 10 Full
Bank49 0x02 bit 1
1 = advertise 10 full-duplex capable.
0 = do not advertise 10 full-duplex capability.
5
1
RW
Adv 10 Half
Bank49 0x02 bit 0
1 = advertise 10 half-duplex capable.
0 = do not advertise 10 half-duplex capability.
4-0
0x01
RO
Selector Field
802.3
Bank 45 PHY 1 Auto-Negotiation Link Partner Ability Register (0x0A): P1ANLPR
This register contains the auto-negotiation link partner ability for the switch port 1 function.
Bit
Default
R/W
Description
15
0
RO
Next page
Bit is same as:
Not supported.
14
0
RO
13
0
RO
LP ACK
Not supported.
Remote fault
Not supported.
12-11
0x0
RO
Reserved
10
0
RO
Pause
Bank 49 0x04 bit 4
Link partner pause capability.
9
0
RO
Reserved
8
0
RO
Adv 100 Full
Bank 49 0x04 bit 3
Link partner 100 full capability.
7
0
RO
Adv 100 Half
Bank 49 0x04 bit 2
Link partner 100 half capability.
6
0
RO
5
0
RO
Adv 10 Full
Bank 49 0x04 bit 1
Link partner 10 full capability.
Adv 10 Half
Bank 49 0x04 bit 0
Link partner 10 half capability.
4-0
0x01
RO
Reserved
Bank 46 PHY 2 MII-Register Basic Control Register (0x00): P2MBCR
This register contains Media Independent Interface (MII) control for the switch function as defined in the IEEE 802.3
specification.
Bit
Default
R/W
Description
15
0
RO
Soft reset
Bit is same as:
Not supported.
14
0
RW
Far-End Loopback
Bank 51 0x02 bit 8
1 = perform loop back, as indicated (see
Figure14):
Start: RXP1/RXM1 (port 1)
Loop back: PMD/PMA of port 2’s PHY
End: TXP1/TXM1 (port 1)
0 = normal operation.
13
0
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RW
Force 100
Bank 51 0x02 bit 6
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Bit
Default
KSZ8842-16/32 MQL/MVL
R/W
Description
Bit is same as:
1 = 100 Mbps.
0 = 10 Mbps.
12
1
RW
AN Enable
Bank 51 0x02 bit 7
1 = auto-negotiation enabled.
0 = auto-negotiation disabled.
11
0
RW
Power Down
Bank 51 0x02 bit 11
1 = power down.
0 = normal operation.
10
0
RO
Isolate
Not supported.
9
0
RW
Restart AN
Bank 51 0x02 bit 13
1 = restart auto-negotiation.
0 = normal operation,
8
0
RW
Force Full Duplex
Bank 51 0x02 bit 5
1 = full duplex.
0 = half duplex.
7
0
RO
Collision test
Not supported.
6
0
RO
Reserved
5
1
R/W
HP_mdix
Bank 51 0x04 bit 15
1 = HP Auto MDI-X mode.
0 = Micrel Auto MDI-X mode.
4
0
RW
Force MDI-X
Bank 51 0x02 bit 9
1 = force MDI-X.
0 = normal operation.
3
0
RW
Disable MDI-X
Bank 51 0x02 bit 10
1 = disable auto MDI-X.
0 = normal operation.
2
0
RW
Disable Far-End-Fault
Bank 51 0x02 bit 12
1 = disable far-end-fault detection.
0 = normal operation.
1
0
RW
Disable Transmit
Bank 51 0x02 bit 14
1 = disable transmit.
0 = normal operation.
0
0
RW
Disable LED
Bank 51 0x02 bit 15
1 = disable LED.
0 = normal operation.
Bank 46 PHY 2 MII-Register Basic Status Register (0x02): P2MBSR
This register contains the MII register for the switch port 2 function.
Bit
Default
R/W
Description
15
0
RO
T4 Capable
14
1
RO
Bit is same as:
0 = not 100 BASE-T4 capable.
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1 = 100BASE-TX full-duplex capable.
0 = not 100BASE-TX full-duplex capable.
13
1
RO
100 Half Capable
1 = 100BASE-TX half-duplex capable.
0 = not 100BASE-TX half-duplex capable.
12
1
RO
10 Full Capable
1 = 10BASE-T full-duplex capable.
0 = not 10BASE-T full-duplex capable.
11
1
RO
10 Half Capable
1 = 10BASE-T half-duplex capable.
0 = not 10BASE-T half-duplex capable.
10-7
0x0
RO
Reserved
6
0
RO
Preamble suppressed
Not supported.
5
0
RO
AN Complete
Bank 51 0x04 bit 6
1 = auto-negotiation complete.
0 = auto-negotiation not complete.
4
0
RO
Far-End-Fault
Bank 51 0x04 bit 8
1 = far-end-fault detected.
0 = no far-end-fault detected.
3
1
RO
AN Capable
1 = auto-negotiation capable.
0 = not auto-negotiation capable.
2
0
RO
Link Status
Bank 51 0x04 bit 5
1 = link is up.
0 = link is down.
1
0
RO
0
0
RO
Jabber test
Not supported.
Extended Capable
0 = not extended register capable.
Bank 46 PHY 2 PHYID Low Register (0x04): PHY2ILR
This register contains the PHY ID (low) for the switch port 2 function.
Bit
Default
R/W
Description
15-0
0x1430
RO
PHYID Low
Low order PHYID bits.
Bank 46 PHY 2 PHYID High Register (0x06): PHY2IHR
This register contains the PHY ID (high) for the switch port 2 function.
Bit
Default
R/W
Description
15-0
0x0022
RO
PHYID High
High order PHYID bits.
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Bank 46 PHY 2 Auto-Negotiation Advertisement Register (0x08): P2ANAR
This register contains the auto-negotiation advertisement for the switch port 2 function.
Bit
Default
R/W
Description
15
0
RO
Next page
Bit is same as:
Not supported.
14
0
RO
Reserved
13
0
RO
Remote fault
12-11
0x0
RO
Reserved
10
1
RW
Pause
Not supported.
Bank 51 0x02 bit 4
1 = advertise pause capability.
0 = do not advertise pause capability.
9
0
RW
Reserved
8
1
RW
Adv 100 Full
Bank 51 0x02 bit 3
1 = advertise 100 full-duplex capability.
0 = do not advertise 100 full-duplex
capability.
7
1
RW
Adv 100 Half
Bank 51 0x02 bit 2
1 = advertise 100 half-duplex capability.
0 = do not advertise 100 half-duplex
capability.
6
1
RW
Adv 10 Full
Bank 51 0x02 bit 1
1 = advertise 10 full-duplex capability.
0 = do not advertise 10 full-duplex capability.
5
1
RW
Bank 51 0x02 bit 0
Adv 10 Half
1= advertise 10 half-duplex capability.
0 = do not advertise 10 half-duplex
capability.
4-0
0x01
RO
Selector Field
802.3
Bank 46 PHY 2 Auto-Negotiation Link Partner Ability Register (0x0A): P2ANLPR
This register contains the auto-negotiation link partner ability for the switch port 2 function.
Bit
Default
R/W
Description
15
0
RO
Next page
Bit is same as:
Not supported.
14
0
RO
13
0
RO
LP ACK
Not supported.
Remote fault
Not supported.
12-11
0x0
RO
Reserved
10
0
RO
Pause
Bank 51 0x04 bit 4
Link partner pause capability.
9
0
RO
Reserved
8
0
RO
Adv 100 Full
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Bank 51 0x04 bit 3
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Link partner 100 full capability.
7
0
RO
Adv 100 Half
Bank 51 0x04 bit 2
Link partner 100 half capability.
6
0
RO
Adv 10 Full
Bank 51 0x04 bit 1
Link partner 10 full capability.
5
0
RO
4-0
0x01
RO
Adv 10 Half
Bank 51 0x04 bit 0
Link partner 10 half capability.
Reserved
Bank 47 PHY1 LinkMD Control/Status (0x00): P1VCT
This register contains the LinkMD control and status information of PHY 1.
Bit
Default
R/W
Description
Bit is same as:
15
0
RW
Vct_enable
Bank 49 0x00 bit 12
(SelfClear)
1 = cable diagnostic test is enabled. It is
self-cleared after the VCT test is done.
0 = indicates that the cable diagnostic test is
completed and the status information is valid
for read.
14-13
0x0
RO
Vct_result
Bank 49 0x00 bit 14-13
[00] = normal condition.
[01] = open condition detected in the cable.
[10] = short condition detected in the cable.
[11] = cable diagnostic test failed.
Vct 10M Short
12
-
RO
11-9
0x0
RO
Reserved
8-0
0x000
RO
Vct_fault_count
Bank 49 0x00 bit 15
1 = Less than 10m short.
Bank 49 0x00 bit 8-0
Distance to the fault. The distance is
approximately 0.4m*vct_fault_count.
Bank 47 PHY1 Special Control/Status Register (0x02): P1PHYCTRL
This register contains the control and status information of PHY1.
Bit
Default
R/W
Description
Bit is same as:
15-6
0x000
RO
Reserved
5
0
RO
Polarity Reverse (polrvs)
Bank 49 0x04 bit 13
1 = polarity is reversed.
0 = polarity is not reversed.
4
0
RO
MDI-X Status (mdix_st)
Bank 49 0x04 bit 7
1 = MDI
0 = MDI-X
3
0
RW
Bank 49 0x00 bit 11
Force Link (force_lnk)
1 = force link pass.
0 = normal operation.
2
1
RW
Power Saving (pwrsave)
Bank 49 0x00 bit 10
1 = disable power saving.
0 = enable power saving.
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1
0
0
0
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RW
Remote (Near-End) Loopback (rlb)
RW
1 = perform remote loopback at Port 1's
PHY (RXP1/RXM1 -> TXP1/TXM1, see
Figure 15)
0 = normal operation
Reserved
Bank 49 0x00 bit 9
Bank 47 PHY2 LinkMD Control/Status (0x04): P2VCT
This register contains the LinkMD control and status information of PHY 2.
Bit
Default
R/W
Description
15
0
RW
Vct_enable
Bit is same as:
Bank 51 0x00 bit 12
1 = the cable diagnostic test is enabled. It is
self-cleared after the VCT test is done.
(Self-Clear)
0 = it indicates the cable diagnostic test is
completed and the status information is valid
for read.
14-13
0x0
RO
Vct_result
Bank 51 0x00 bit 14-13
[00] = normal condition.
[01] = open condition detected in the cable.
[10] = short condition detected in the cable.
[11] = cable diagnostic test failed.
12
-
RO
Bank 51 0x00 bit 15
Vct 10M Short
1 = Less than 10m short.
11-9
0x0
RO
Reserved
8-0
0x000
RO
Vct_fault_count
Bank 51 0x00 bit 8-0
Distance to the fault. The distance is
approximately 0.4m*vct_fault_count.
Bank 47 PHY2 Special Control/Status Register (0x06): P2PHYCTRL
This register contains the control and status information of PHY2.
Bit
Default
R/W
15-6
0x000
RO
Reserved
RO
Polarity reverse (polrvs)
5
0
Description
Bit is same as:
Bank 51 0x04 bit 13
1 = polarity is reversed.
0 = polarity is not reversed.
4
0
RO
MDIX Status (mdix_st)
Bank 51 0x04 bit 7
1 = MDI
0 = MDI-X
3
0
RW
Force Link (force_lnk)
Bank 51 0x00 bit 11
1 = force link pass.
0 = normal operation.
2
1
RW
Bank 51 0x00 bit 10
Power Saving (pwrsave)
1 = disable power saving.
0 = enable power saving.
1
0
RW
Remote (Near-End) Loopback (rlb)
Bank 51 0x00 bit 9
1 = perform remote loopback at Port 2's
PHY(RXP2/RXM2 -> TXP2/TXM2. see
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Figure 15)
0 = normal operation
0
0
RW
Reserved
Bank 48 Port 1 Control Register 1 (0x00): P1CR1
This register contains the global per port control for the switch function.
Bit
Default
R/W
Description
15-8
0x00
RO
Reserved
7
0
RW
Broadcast Storm Protection Enable
1 = enable broadcast storm protection for ingress packets on the port.
0 = disable broadcast storm protection.
6
0
RW
Diffserv Priority Classification Enable
1= enable DiffServ priority classification for ingress packets on the port.
0 = disable DiffServ function.
5
0
RW
802.1p Priority Classification Enable
1= enable 802.1p priority classification for ingress packets on the port.
0 = disable 802.1p.
4-3
0x0
RW
Port-Based Priority Classification
00 - ingress packets on port are classified as priority 0 queue if “DiffServ” or “802.1p”
classification is not enabled or fails to classify.
01 - ingress packets on port are classified as priority 1 queue if “DiffServ” or “802.1p”
classification is not enabled or fails to classify.
10 - ingress packets on port are classified as priority 2 queue if “DiffServ” or “802.1p”
classification is not enabled or fails to classify.
11 - ingress packets on port are classified as priority 3 queue 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.
2
0
RW
Tag Insertion
1 = when packets are output on the port, the switch adds 802.1p/q tags to packets without
802.1p/q 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.
1
0
RW
Tag Removal
1 = when packets are output on the port, the switch removes 802.1p/q tags from packets
with 802.1p/q tags when received. The switch will not modify packets received without tags.
0 = disable tag removal.
0
0
RW
TX Multiple Queues Select Enable
1 = the port output queue is split into four priority queues.
0 = single output queue on the port. There is no priority differentiation even though packets
are classified into high or low priority.
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Bank 48 Port 1 Control Register 2 (0x02): P1CR2
This register contains the global per port control for the switch function.
Bit
Default
R/W
Description
15
0
RW
Reserved
14
0
RW
Ingress VLAN Filtering
1= the switch discards packets whose VID port membership in VLAN table bits [18:16]
does not include the ingress port VID.
0 = no ingress VLAN filtering.
13
0
RW
Discard Non PVID Packets
1 = the switch discards packets whose VID does not match the ingress port default
VID.
0 = no packets are discarded.
12
0
RW
Force Flow Control
1 = always enable flow control on the port, regardless of AN result.
0 = the flow control is enabled based on AN result.
11
0
RW
Back Pressure Enable
1 = enable port’s half-duplex back pressure.
0 = disable port’s half-duplex back pressure.
10
1
RW
Transmit Enable
1 = enable packet transmission on the port.
0 = disable packet transmission on the port.
9
1
RW
Receive Enable
1 = enable packet reception on the port.
0 = disable packet reception on the port.
8
0
RW
Learning Disable
1 = disable switch address learning capability.
0 = enable switch address learning.
7
0
RW
Sniffer Port
1 = port is designated as a sniffer port and transmits packets that are monitored.
0 = port is a normal port.
6
0
RW
Receive Sniff
1 = all packets received on the port are marked as “monitored packets” and forwarded
to the designated “sniffer port.”
0 = no receive monitoring.
5
0
RW
Transmit Sniff
1 = all packets transmitted on the port are marked as “monitored packets” and
forwarded to the designated “sniffer port.”
0 = no transmit monitoring.
4
0
RW
Reserved
3
0
RW
User Priority Ceiling
1 = if the packet’s “priority field” is greater than the “user priority field” in the port VID
control register bit[15:13], replace the packet’s “priority field” with the “user priority
field” in the port VID control register bit[15:13].
0 = do no compare and replace the packet’s “priority field.”
2-0
0x7
RW
Port VLAN Membership
Define the port’s Port VLAN membership. Bit 2 stands for the host port, bit 1 for port 2,
and 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 the membership.
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Bank 48 Port 1 VID Control Register (0x04): P1VIDCR
This register contains the global per port control for the switch function.
Bit
Default
R/W
Description
15-13
0x0
RW
Default Tag[15:13]
Port’s default tag, containing “User Priority Field” bits.
12
0
RW
11-0
0x001
RW
Default Tag[12]
Port’s default tag, containing CFI bit.
Default Tag[11:0]
Port’s default tag, containing VID[11:0].
Note: This VID Control register serves 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 lookup.
Bank 48 Port 1 Control Register 3 (0x06): P1CR3
Bit
Default
R/W
Description
15-5
0x000
RO
Reserved
4
0x0
RW
Reserved
3-2
0x0
RW
Ingress Limit Mode
These bits determine what kinds of frames are limited and counted against Ingress
limiting as follows:
00 = Limit and count all frames.
01 = Limit and count Broadcast, Multicast, and flooded unicast frames.
10 = Limit and count Broadcast and Multicast frames only.
11 = Limit and count Broadcast frames only.
1
0
RW
Count IFG
Count IFG Bytes.
1= each frame’s minimum inter frame gap.
(IFG) bytes (12 per frame) are included in Ingress and Egress rate limiting
calculations.
0= IFG bytes are not counted.
0
0
RW
Count Preamble
Count preamble Bytes.
1 = each frame’s preamble bytes (8 per frame) are included in Ingress and Egress rate
limiting calculations.
0 = preamble bytes are not counted.
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Bank 48 Port 1 Ingress Rate Control Register (0x08): P1IRCR
Bit
Default
R/W
Description
15-12
0x0
RW
Ingress Pri3 Rate
Priority 3 frames will be discarded after the ingress rate selected as shown below is
reached or exceeded.
0000 = Not limited (default)
0001 = 64Kbps
0010 = 128Kbps
0011 = 256Kbps
0100 = 512Kbps
0101 = 1Mbps
0110 = 2Mbps
0111 = 4Mbps
1000 = 8Mbps
1001 = 16Mbps
1010 = 32Mbps
1011 = 48Mbps
1100 = 64 Mbps
1101 = 72Mbps
1110 = 80Mbps
1111 = 88Mbps
Note: For 10BT, rate settings above 10Mbps are set to the default value 0000 (not
limited).
11-8
0x0
RW
Ingress Pri2 Rate
Priority 2 frames will be discarded after the ingress rate selected as shown below is
reached or exceeded.
0000 = Not limited (default)
0001 = 64Kbps
0010 = 128Kbps
0011 = 256Kbps
0100 = 512Kbps
0101 = 1Mbps
0110 = 2Mbps
0111 = 4Mbps
1000 = 8Mbps
1001 = 16Mbps
1010 = 32Mbps
1011 = 48Mbps
1100 = 64 Mbps
1101 = 72Mbps
1110 = 80Mbps
1111 = 88Mbps
Note: For 10BT, rate settings above 10Mbps are set to the default value 0000 (not
limited).
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Bit
Default
R/W
Description
7-4
0x0
RW
Ingress Pri1 Rate
Priority 1 frames will be discarded after the ingress rate selected as shown below is
reached or exceeded.
0000 = Not limited (default)
0001 = 64Kbps
0010 = 128Kbps
0011 = 256Kbps
0100 = 512Kbps
0101 = 1Mbps
0110 = 2Mbps
0111 = 4Mbps
1000 = 8Mbps
1001 = 16Mbps
1010 = 32Mbps
1011 = 48Mbps
1100 = 64 Mbps
1101 = 72Mbps
1110 = 80Mbps
1111 = 88Mbps
Note: For 10BT, rate settings above 10Mbps are set to the default value 0000 (not
limited).
3-0
0x0
RW
Ingress Pri0 Rate
Priority 0 frames will be discarded after the ingress rate selected as shown below is
reached or exceeded.
0000 = Not limited (default)
0001 = 64Kbps
0010 = 128Kbps
0011 = 256Kbps
0100 = 512Kbps
0101 = 1Mbps
0110 = 2Mbps
0111 = 4Mbps
1000 = 8Mbps
1001 = 16Mbps
1010 = 32Mbps
1011 = 48Mbps
1100 = 64 Mbps
1101 = 72Mbps
1110 = 80Mbps
1111 = 88Mbps
Note: For 10BT, rate settings above 10Mbps are set to the default value 0000 (not
limited).
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Bank 48 Port 1 Egress Rate Control Register (0x0A): P1ERCR
Bit
Default
R/W
Description
15-12
0x0
RW
Egress Pri3 Rate
Egress data rate limit for priority 3 frames.
Output traffic from this priority queue is shaped according to the egress rate selected
below:
0000 = Not limited (default)
0001 = 64Kbps
0010 = 128Kbps
0011 = 256Kbps
0100 = 512Kbps
0101 = 1Mbps
0110 = 2Mbps
0111 = 4Mbps
1000 = 8Mbps
1001 = 16Mbps
1010 = 32Mbps
1011 = 48Mbps
1100 = 64 Mbps
1101 = 72Mbps
1110 = 80Mbps
1111 = 88Mbps
Notes: For 10BT, rate settings above 10Mbps are set to the default value 0000 (not
limited).
When multiple queue select enable is off (only 1 queue per port), rate limiting applies
only to priority 0 queue.
11-8
0x0
RW
Egress Pri2 Rate
Egress data rate limit for priority 2 frames.
Output traffic from this priority queue is shaped according to the egress rate selected
below:
0000 = Not limited (default)
0001 = 64Kbps
0010 = 128Kbps
0011 = 256Kbps
0100 = 512Kbps
0101 = 1Mbps
0110 = 2Mbps
0111 = 4Mbps
1000 = 8Mbps
1001 = 16Mbps
1010 = 32Mbps
1011 = 48Mbps
1100 = 64 Mbps
1101 = 72Mbps
1110 = 80Mbps
1111 = 88Mbps
Notes: For 10BT, rate settings above 10Mbps are set to the default value 0000 (not
limited).
When multiple queue select enable is off (only 1 queue per port), rate limiting applies
only to priority 0 queue.
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Bit
Default
R/W
Description
7-4
0x0
RW
Egress Pri1 Rate
Egress data rate limit for priority 1 frames.
Output traffic from this priority queue is shaped according to the egress rate selected
below:
0000 = Not limited (default)
0001 = 64Kbps
0010 = 128Kbps
0011 = 256Kbps
0100 = 512Kbps
0101 = 1Mbps
0110 = 2Mbps
0111 = 4Mbps
1000 = 8Mbps
1001 = 16Mbps
1010 = 32Mbps
1011 = 48Mbps
1100 = 64 Mbps
1101 = 72Mbps
1110 = 80Mbps
1111 = 88Mbps
Notes: For 10BT, rate settings above 10Mbps are set to the default value 0000 (not
limited).
When multiple queue select enable is off (only 1 queue per port), rate limiting applies
only to priority 0 queue.
3-0
0x0
RW
Egress Pri0 Rate
Egress data rate limit for priority 0 frames.
Output traffic from this priority queue is shaped according to the egress rate selected
below:
0000 = Not limited (default)
0001 = 64Kbps
0010 = 128Kbps
0011 = 256Kbps
0100 = 512Kbps
0101 = 1Mbps
0110 = 2Mbps
0111 = 4Mbps
1000 = 8Mbps
1001 = 16Mbps
1010 = 32Mbps
1011 = 48Mbps
1100 = 64 Mbps
1101 = 72Mbps
1110 = 80Mbps
1111 = 88Mbps
Notes: For 10BT, rate settings above 10Mbps are set to the default value 0000 (not
limited).
When multiple queue select enable is off (only 1 queue per port), rate limiting applies
only to priority 0 queue.
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Bank 49 Port 1 PHY Special Control/Status, LinkMD (0x00): P1SCSLMD
Bit
Default
R/W
Description
Bit is same as:
15
0
RO
Vct_10m_short
Bank 47 0x00 bit 12
14-13
0x0
RO
1 = Less than 10 meter short.
Vct_result
Bank 47 0x00 bit 14-13
VCT result.
[00] = normal condition.
[01] = open condition has been detected in
cable.
[10] = short condition has been detected in
cable.
[11] = cable diagnostic test is failed.
12
0
RW
Vct_en
SC
Vct enable.
Bank 47 0x00 bit 15
1 = the cable diagnostic test is enabled. It
is self-cleared after the VCT test is done.
0 = it indicates the cable diagnostic test is
completed and the status information is
valid for read.
11
0
RW
Force_lnk
Bank 47 0x02 bit 3
Force link.
1 = force link pass.
0 = normal operation.
10
1
RW
pwrsave
Bank 47 0x02 bit 2
Power-saving.
1 = disable power saving.
0 = enable power saving.
9
0
RW
Remote (Near-End) Loopback (rlb)
Bank 47 0x02 bit 1
1 = perform remote loopback at Port 1's
PHY (RXP1/RXM1 -> TXP1/TXM1, see
Figure 15)
0 = normal operation
8-0
0x000
RO
Vct_fault_count
Bank 47 0x00 bit 8-0
VCT fault count.
Distance to the fault. It’s approximately
0.4m*vct_fault_count.
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Bank 49 Port 1 Control Register 4 (0x02): P1CR4
This register contains the global per port control for the switch function.
Bit
Default
R/W
Description
Bit is same as:
15
0
RW
LED Off
Bank 45 0x00 bit 0
1 = Turn off all of the port 1 LEDs (P1LED3,
P1LED2, P1LED1, P1LED0). These pins are driven
high if this bit is set to one.
0 = normal operation.
14
0
RW
Txids
Bank 45 0x00 bit1
1 = disable the port’s transmitter.
0 = normal operation.
13
0
RW
Restart AN
Bank 45 0x00 bit 9
1 = restart auto-negotiation.
0 = normal operation.
12
0
RW
Disable Far-End-Fault
Bank 45 0x00 bit 2
1 = disable far-end-fault detection and pattern
transmission.
0 = enable far end fault detection and pattern
transmission.
11
0
RW
Power Down
Bank 45 0x00 bit 11
1 = power down.
0 = normal operation.
10
0
RW
Disable auto MDI/MDI-X
Bank 45 0x00 bit 3
1 = disable auto MDI/MDI-X function.
0 = enable auto MDI/MDI-X function.
9
0
RW
Force MDI-X
Bank 45 0x00 bit 4
1= if auto MDI/MDI-X is disabled, force PHY into
MDI-X mode.
0 = do not force PHY into MDI-X mode.
8
0
RW
Far-End Loopback
Bank 45 0x00 bit 14
1 = perform loopback, as indicated:
Start: RXP2/RXM2 (port 2).
Loopback: PMD/PMA of port 1’s PHY.
End: TXP2/TXM2 (port 2).
0 = normal operation.
7
1
RW
Auto Negotiation Enable
Bank 45 0x00 bit 12
1 = auto negotiation is enabled.
0 = disable auto negotiation, speed, and duplex are
decided by bits 6 and 5 of the same register.
6
0
RW
Force Speed
Bank 45 0x00 bit 13
1 = force 100BT if AN is disabled (bit 7).
0 = force 10BT if AN is disabled (bit 7).
5
0
RW
Force Duplex
Bank 45 0x00 bit 8
1 = force full duplex if (1) AN is disabled or (2) AN is
enabled but failed.
0 = force half duplex if (1) AN is disabled or (2) AN
is enabled but failed.
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Bit
4
Default
1
KSZ8842-16/32 MQL/MVL
R/W
RW
Description
Bit is same as:
Advertised flow control capability.
Bank 45 0x08 bit 10
1 = advertise flow control (pause) capability.
0 = suppress flow control (pause) capability from
transmission to link partner.
3
1
RW
Advertised 100BT full-duplex capability.
Bank 45 0x08 bit 8
1 = advertise 100BT full-duplex capability.
0 = suppress 100BT full-duplex capability from
transmission to link partner.
2
1
RW
Advertised 100BT half-duplex capability.
Bank 45 0x08 bit 7
1 = advertise 100BT half-duplex capability.
0 = suppress 100BT half-duplex capability from
transmission to link partner.
1
1
RW
Advertised 10BT full-duplex capability.
Bank 45 0x08 bit 6
1 = advertise 10BT full-duplex capability.
0 = suppress 10BT full-duplex capability from
transmission to link partner.
0
1
RW
Advertised 10BT half-duplex capability.
Bank 45 0x08 bit 5
1 = advertise 10BT half-duplex capability.
0 = suppress 10BT half-duplex capability from
transmission to link partner.
Bank 49 Port 1 Status Register (0x04): P1SR
This register contains the global per port status for the switch function.
Bit
Default
R/W
Description
Bit is same as:
15
1
RW
HP_mdix
Bank 45 0x00 bit 5
1 = HP Auto MDI-X mode.
0 = Micrel Auto MDI-X mode.
14
0
RO
Reserved
13
0
RO
Polarity Reverse
Bank 47 0x02 bit 5
1 = polarity is reversed.
0 = polarity is not reversed.
12
0
RO
Receive Flow Control Enable
1 = receive flow control feature is active.
0 = receive flow control feature is inactive.
11
0
RO
Transmit Flow Control Enable
1 = transmit flow control feature is active.
0 = transmit flow control feature is inactive.
10
0
RO
Operation Speed
1 = link speed is 100Mbps.
0 = link speed is 10Mbps.
9
0
RO
Operation Duplex
1 = link duplex is full.
0 = link duplex is half.
8
0
RO
Far-End-Fault
Bank 45 0x02 bit 4
1 = far-end-fault status detected.
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Bit
Default
KSZ8842-16/32 MQL/MVL
R/W
Description
Bit is same as:
0 = no Far-end-fault status detected.
7
0
RO
MDI-X status
Bank 47 0x02 bit 4
1 = MDI.
0 = MDI-X.
6
0
RO
AN Done
Bank 45 0x02 bit 5
1 = AN done.
0 = AN not done.
5
0
RO
Link Good
Bank 45 0x02 bit 2
1 = link good.
0 = link not good.
4
0
RO
Partner flow control capability.
Bank 45 0x0A bit 10
1 = link partner flow control (pause) capable.
0 = link partner not flow control (pause) capable.
3
0
RO
Partner 100BT full-duplex capability.
Bank 45 0x0A bit 8
1 = link partner 100BT full-duplex capable.
0 = link partner not 100BT full-duplex capable.
2
0
RO
Partner 100BT half-duplex capability.
Bank 45 0x0A bit 7
1 = link partner 100BT half-duplex capable.
0= link partner not 100BT half-duplex capable.
1
0
RO
Partner 10BT full-duplex capability.
Bank 45 0x0A bit 6
1= link partner 10BT full-duplex capable.
0 = link partner not 10BT full-duplex capable.
0
0
RO
Partner 10BT half-duplex capability.
Bank 45 0x0A bit 5
1 = link partner 10BT half-duplex capable.
0 = link partner not 10BT half-duplex capable.
Bank 50 Port 2 Control Register 1 (0x00): P2CR1
This register contains the global per port control for the switch function. See description in P1CR1, Bank 48 (0x00)
Bank 50 Port 2 Control Register 2 (0x02): P2CR2
This register contains the global per port control for the switch function. See description in P1CR2, Bank 48 (0x02)
Bank 50 Port 2 VID Control Register (0x04): P2VIDCR
This register contains the global per port control for the switch function. See description in P1VIDCR, Bank 48 (0x04)
Bank 50 Port 2 Control Register 3 (0x06): P2CR3
This register contains the global per port control for the switch function. See description in P1CR3, Bank 48 (0x06)
Bank 50 Port 2 Ingress Rate Control Register (0x08): P2IRCR
This register contains per port ingress rate control. See description in P1IRCR, Bank 48 (0x08)
Bank 50 Port 2 Egress Rate Control Register (0x0A): P2ERCR
This register contains per port egress rate control. See description in P1ERCR, Bank 48 (0x0A)
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Bank 51 Port 2 PHY Special Control/Status, LinkMD (0x00): P2SCSLMD
Bit
Default
R/W
Description
Bit is same as:
15
0
RO
Vct_10m_short
Bank 47 0x04 bit 12
14-13
0x0
RO
1 = Less than 10 meter short.
Vct_result
Bank 47 0x04 bit 14-13
VCT result.
[00] = normal condition.
[01] = open condition has been detected
in the cable.
[10] = short condition has been detected
in the cable.
[11] = cable diagnostic test has failed.
12
11
0
0
RW
Vct_en
SC
VCT enable.
1 = the cable diagnostic test is enabled. It
is self-cleared after the VCT test is done.
0 = it indicates the cable diagnostic test is
completed and the status information is
valid for read
RW
Force_lnk
Bank 47 0x04 bit 15
Bank 47 0x06 bit 3
Force link.
1 = force link pass.
0 = normal operation.
10
1
RW
Pwrsave
Bank 47 0x06 bit 2
Power-saving.
1 = disable power saving.
0 = enable power saving.
9
0
RW
Remote (Near-End) Loopback (rlb)
Bank 47 0x06 bit 1
1 = perform remote loopback at Port 2's
PHY (RXP2/RXM2 -> TXP2/TXM2, see
Figure 15)
0 = normal operation
8-0
0x000
RO
Vct_fault_count
Bank 47 0x04 bit 8-0
VCT fault count.
The distance to the fault is approximately
0.4m*vct_fault_count.
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Bank 51 Port 2 Control Register 4 (0x02): P2CR4
This register contains the global per port control for the switch function.
Bit
Default
R/W
Description
Bit is same as:
15
0
RW
LED Off
Bank 46 0x00 bit 0
1 = turn off all of the port 2 LEDs (P2LED3,
P2LED2, P2LED1, P2LED0). These pins are driven
High if this bit is set to 1.
0 = normal operation.
14
0
RW
Txids
Bank 46 0x00 bit 1
1 = disable port’s transmitter.
0 = normal operation.
13
0
RW
Restart AN
Bank 46 0x00 bit 9
1 = restart auto-negotiation.
0 = normal operation.
12
0
RW
Disable Far-End-Fault
Bank 46 0x00 bit 2
1 = disable far end fault detection and pattern
transmission.
0 = enable far end fault detection and pattern
transmission.
11
0
RW
Power Down
Bank 46 0x00 bit 11
1 = power-down.
0 = normal operation.
10
0
RW
Disable Auto MDI/MDI-X
Bank 46 0x00 bit 3
1= disable auto MDI/MDI-X function.
0= enable auto MDI/MDI-X function.
9
0
RW
Force MDI-X
Bank 46 0x00 bit 4
1 = if auto MDI/MDI-X is disabled, force PHY into
MDI-X mode.
0 = do not force PHY into MDI-X mode.
8
0
RW
Far-End Loopback
Bank 46 0x00 bit 14
1 = perform loopback, as indicated (see Figure 14):
Start: RXP1/RXM1 (port 1).
Loopback: PMD/PMA of port 2’s PHY.
End: TXP1/TXM1 (port 1).
0 = normal operation.
7
1
RW
Auto Negotiation Enable
Bank 46 0x00 bit 12
0 = disable auto negotiation, speed and duplex are
decided by bits 6 and 5 of the same register.
1 = auto negotiation is ON.
6
0
RW
Force Speed
Bank 46 0x00 bit 13
1 = force 100BT if AN is disabled (bit 7).
0 = force 10BT if AN is disabled (bit 7).
5
0
RW
Force Duplex
Bank 46 0x00 bit 8
1 = force full duplex if (1) AN is disabled or (2) AN is
enabled but failed.
0 = force half duplex if (1) AN is disabled or (2) AN
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Bit
Default
R/W
Description
is enabled but failed.
Bit is same as:
4
1
RW
Advertised flow control capability.
Bank 46 0x08 bit 10
1 = advertise flow control (pause) capability.
0 = suppress flow control (pause) capability from
transmission to the link partner.
3
1
RW
Advertised 100BT Full-duplex capability.
Bank 46 0x08 bit 8
1 = advertise 100BT full-duplex capability.
0 = suppress 100BT full-duplex capability from
transmission to the link partner.
2
1
RW
Advertised 100BT half-duplex capability.
Bank 46 0x08 bit 7
1 = advertise 100BT half-duplex capability.
1 = suppress 100BT half-duplex capability from
transmission to the link partner.
1
1
RW
Advertised 10BT full-duplex capability.
Bank 46 0x08 bit 6
1 = advertise 10BT full-duplex capability.
0 = suppress 10BT full-duplex capability from
transmission to the link partner.
0
1
RW
Advertised 10BT half-duplex capability.
Bank 46 0x08 bit 5
1 = advertise 10BT half-duplex capability.
0 = suppress 10BT half-duplex capability from
transmission to the link partner.
Bank 51 Port 2 Status Register (0x04): P2SR
This register contains the global per port status for the switch function.
Bit
Default
R/W
Description
Bit is same as:
15
1
RW
HP_mdix
Bank 46 0x00 bit 5
1 = HP Auto MDI-X mode.
0 = Micrel Auto MDI-X mode.
14
0
RO
Reserved
13
0
RO
Polarity Reverse
Bank 47 0x06 bit 5
1 = polarity is reversed.
0 = polarity is not reversed.
12
0
RO
Receive Flow Control Enable
1 = receive flow control feature is active.
0 = receive flow control feature is inactive.
11
0
RO
Transmit Flow Control Enable
1 = transmit flow control feature is active.
0 = transmit flow control feature is inactive.
10
0
RO
Operation Speed
1 = link speed is 100Mbps.
0 = link speed is 10Mbps.
9
0
RO
Operation Duplex
1 = link duplex is full.
0 = link duplex is half.
8
0
November 2005
RO
Far-End-Fault
Bank 46 0x02 bit 4
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Bit
Default
KSZ8842-16/32 MQL/MVL
R/W
Description
Bit is same as:
1 = far-end-fault status detected.
0 = no Far end fault status detected.
7
0
MDI-X Status
RO
Bank 47 0x06 bit 4
1 = MDI.
0 = MDI-X.
6
0
AN Done
RO
Bank 46 0x02 bit 5
1 = AN done.
0 = AN not done.
5
0
Link Good
RO
Bank 46 0x02 bit 2
1 = link good.
0 = link not good.
4
0
Partner flow control capability.
RO
Bank 46 0x0A bit 10
1 = link partner flow control (pause) capable.
0 = link partner not flow control (pause) capable.
3
0
Partner 100BT full-duplex capability.
RO
Bank 46 0x0A bit 8
1 = link partner 100BT full-duplex capable.
0 = link partner not 100BT full-duplex capable.
2
0
Partner 100BT half duplex capability.
RO
Bank 46 0x0A bit 7
1 = link partner 100BT half-duplex capable.
0 = link partner not 100BT half-duplex capable.
1
0
Partner 10BT full-duplex capability.
RO
Bank 46 0x0A bit 6
1 = link partner 10BT full-duplex capable.
0 = link partner not 10BT full-duplex capable.
0
0
Partner 10BT half-duplex capability.
RO
Bank 46 0x0A bit 5
1 = link partner 10BT half-duplex capable.
0 = link partner not 10BT half-duplex capable.
Bank 52 Host Port Control Register 1 (0x00): P3CR1
This register contains the global per port control for the switch function. See description in P1CR1, Bank 48 (0x00)
Bank 52 Host Port Control Register 2 (0x02): P3CR2
This register contains the global per port control for the switch function.
Bit
Default
15
0
R/W
Description
14
0
RW
Ingress VLAN Filtering
1 = the switch discards packets whose VID port membership in VLAN table bits
[18:16] does not include the ingress port.
0 = no ingress VLAN filtering.
13
0
RW
Discard Non PVID Packets
1 = the switch discards packets whose VID does not match the ingress port default
VID.
0 = no packets are discarded.
12
0
RO
Reserved
Reserved
11
0
RO
Reserved
10
1
RW
Transmit Enable
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Bit
Default
KSZ8842-16/32 MQL/MVL
R/W
Description
1 = enable packet transmission on the port.
0 = disable packet transmission on the port.
9
1
RW
Receive Enable
1 = enable packet reception on the port.
0 = disable packet reception on the port.
8
0
RW
Learning Disable
1 = disable switch address learning capability.
0 = enable switch address learning.
7
0
RW
Sniffer Port
1 = port is designated as the sniffer port and transmits packets that are monitored.
0 = port is a normal port.
6
0
RW
Receive Sniff
1 = all packets received on the port are marked as “monitored packets” and
forwarded to the designated “sniffer port”.
0 = no receive monitoring.
5
0
RW
Transmit Sniff
1 = all packets transmitted on the port are marked as “monitored packets” and
forwarded to the designated “sniffer port”.
0 = no transmit monitoring.
4
0
RW
Reserved
3
0
RW
User Priority Ceiling
1 = if the packet’s “user priority field” is greater than the “user priority field” in the
port default tag register, replace the packet’s “user priority field” with the “user
priority field” in the port default tag register.
0 = do no compare and replace the packet’s ‘user priority field.”
2-0
0x7
RW
Port VLAN Membership
Define the port’s Port VLAN membership. Bit 2 stands for host port, bit 1 for port 2,
and 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 the membership.
Bank 52 Host Port VID Control Register (0x04): P3VIDCR
This register contains the global per port control for the switch function. See description in P1VIDCR, Bank 48 (0x04)
Bank 52 Host Port Control Register 3 (0x06): P3CR3
This register contains the global per port control for the switch function. See description in P1CR3, Bank 48 (0x06)
Bank 52 Host Port Ingress Rate Control Register (0x08): P3IRCR
This register contains per port ingress rate control. See description in P1IRCR, Bank 48 (0x08)
Bank 52 Host Port Egress Rate Control Register (0x0A): P3ERCR
This register contains per port egress rate control. See description in P1ERCR, Bank 48 (0x0A)
Banks 53 – 63: Reserved
Except Bank Select Register (0xE)
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MIB (Management Information Base) Counters
The KSZ8842M provides 34 MIB counters for each port. These counters are used to monitor the port activity for network
management. The MIB counters are formatted “per port” as shown in Table 14 and “all ports dropped packet” as shown in
Table 16.
Bit
Name
R/W
Description
Default
31
Overflow
RO
1: counter overflow.
0
30
Count valid
RO
0: no counter overflow.
1: counter value is valid.
0
0: counter value is not valid.
29-0
Counter values
RO
Counter value (read clear)
0x00000000
Table 14. Format of Per Port MIB Counters
“Per Port” MIB counters are read using indirect memory access. The base address offsets and address ranges for both
Ethernet ports are:
Port 1, base address is 0x00 and range is from 0x00 to 0x1f.
Port 2, base address is 0x20 and range is from 0x20 to 0x3f.
Per port MIB counters are read using indirect access control register in IACR, Bank 42 (0x00) and indirect access data
registers in IADR4[15:0], IADR5[31:16]. Table 15 shows the port 1 MIB counters address memory offset.
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 1522 bytes w/ either CRC errors, alignment errors, or symbol
errors (depends on max packet size setting)
0x6
RxSymbolError
Rx packets w/ invalid data symbol and legal 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
Number of MAC control frames received by a port with 88-08h in EtherType field
0xA
RxPausePkts
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 error broadcast packets or valid multicast
packets)
0xC
RxMulticast
Rx good multicast packets (not including MAC control frames, error 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
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Offset
Counter Name
Description
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
Number of PAUSE frames transmitted by a port
0x18
TxBroadcastPkts
Tx good broadcast packets (not including error broadcast or valid multicast packets)
0x19
TxMulticastPkts
Tx good multicast packets (not including error multicast packets or valid broadcast
packets)
0x1A
0x1B
TxUnicastPkts
TxDeferred
Tx good unicast packets
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 15. Port 1 MIB Counters Indirect Memory Offset
Format of “All Ports Dropped Packet” MIB Counters
Bit
Default
R/W
Description
30-16
-
N/A
Reserved
15-0
0x0000
RO
Counter Value
Table 16. “All Ports Dropped Packet” MIB Counters Format
Note: “All Ports Dropped Packet” MIB Counters do not indicate overflow or validity; therefore, the application must keep track of
overflow and valid conditions.
“All Ports Dropped Packet” MIB counters are read using indirect memory access. The address offsets for these counters
are shown in Table 17.
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
0x103
Port1 RX Drop Packets
RX packets dropped due to lack of resources
0x104
Port2 RX Drop Packets
RX packets dropped due to lack of resources
Table 17. “All Ports Dropped Packet” MIB Counters Indirect Memory Offsets
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Examples:
1. MIB Counter Read (read port 1 “Rx64Octets” counter at indirect address offset 0x0E)
Write to reg. IACR with 0x1c0e (set indirect address and trigger a read MIB counters operation)
Then
Read reg. IADR5 (MIB counter value 31-16) // If bit 31 = 1, there was a counter overflow
// If bit 30 = 0, restart (reread) from this register
Read reg. IADR4 (MIB counter value 15-0)
2. MIB Counter Read (read port 2 “Rx64Octets” counter at indirect address offset 0x2E)
Write to reg. IACR with 0x1c2e (set indirect address and trigger a read MIB counters operation)
Then
Read reg. IADR5 (MIB counter value 31-16) // If bit 31 = 1, there was a counter overflow
// If bit 30 = 0, restart (reread) from this register
Read reg. IADR4 (MIB counter value 15-0)
3. MIB Counter Read (read “Port1 TX Drop Packets” counter at indirect address offset 0x100)
Write to reg. IACR with 0x1d00 (set indirect address and trigger a read MIB counters operation)
Then
Read reg. IADR4 (MIB counter value 15-0)
Additional MIB Information
Per Port MIB counters are designed as “read clear”. That is, these counters will be cleared after they are read.
All Ports 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.
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Static MAC Address Table
The KSZ8842M supports both a static and a dynamic MAC address table. In response to a Destination Address (DA) look
up, The KSZ8842M searches both tables to make a packet forwarding decision. In response to a Source Address (SA)
look up, only the dynamic table is searched for aging, migration and learning purposes.
The static DA look up result takes precedence over the dynamic DA look up result. If there is a DA match in both tables,
the result from the static table is used. These entries in the static table will not be aged out by the KSZ8842M.
Bit
Default Value
R/W
Description
57-54
0000
RW
53
0
R/W
52
0
R/W
51
0
R/W
50-48
000
R/W
47-0
0
R/W
FID
Filter VLAN ID - identifies one of the 16 active VLANs.
Use FID
1: specifies the useof FID+MAC for static table look ups
0: specifies only the use of MAC for static table look ups
Override
1: overrides the port setting “transmit enable = 0” or “receive enable = 0” setting.
0: specifies no override
Valid
1: specifies that this entry is valid, the look up result will be used
0: specifies that this entry is not valid
Forwarding ports
These 3 bits control the forwarding port(s):
000: no forward
001: forward to port 1
010: forward to port 2
100: forward to port 3
011: forward to port 1 and port 2
110: forward to port 2 and port 3
101: forward to port 1 and port 3
111: broadcasting (excluding the ingress port)
MAC address
48 bits MAC Address
Table 18. Static MAC Table Format
Static MAC Table Lookup Examples:
1. Static Address Table Read (read the second entry at indirect address offset 0x01)
Write to reg. IACR with 0x1001 (set indirect address and trigger a read static MAC table operation)
Then
Read reg. IADR3 (static MAC table bits 57-48)
Read reg. IADR2 (static MAC table bits 47-32)
Read reg. IADR5 (static MAC table bits 31-16)
Read reg. IADR4 (static MAC table bits 15-0)
2. Static Address Table Write (write the eighth entry at indirect address offset 0x07)
Write to reg. IADR3 (static MAC table bits 57-48)
Write to reg. IADR2 (static MAC table bits 47-32)
Write to reg. IADR5 (static MAC table bits 31-16)
Write to reg. IADR4 (static MAC table bits 15-0)
Write to reg. IACR with 0x0007 (set indirect address and trigger a write static MAC table operation)
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Dynamic MAC Address Table
The Dynamic MAC address is a read only table.
Bit
Default Value
71
R/W
Description
RO
Data not ready
1: specifies that the entry is not ready, continue retrying until bit is set to 0
0: specifies that the entry is ready
70-67
66
1
RO
Reserved
RO
MAC empty
1: specifies that there is no valid entry in the table
0: specifies that there are valid entries in the table
65-56
0x000
RO
No of valid entries
Indicates how many valid entries in the table
0x3ff means 1 K entries
0x001 means 2 entries
0x000 and bit 66 = 0 means 1 entry
0x000 and bit 66 = 1 means 0 entry
55-54
RO
Time Stamp
Specifies the 2-bit counter for internal aging.
53-52
00
RO
Source port
Identifies the source port where FID+MAC is learned:
00: port 1
01: port 2
10: port 3
51-48
0x0
RO
47-0
0x0000_0000_0000
RO
FID
Specifies the filter ID.
MAC Address
Specifies the 48-bit MAC address.
Table 19. Dynamic MAC Address Table Format
Dynamic MAC Address Lookup Example:
Dynamic MAC Address Table Read (read the first entry at indirect address offset 0 and retrieve the MAC
table size)
Write to reg. IACR with 0x1800 (set indirect address and trigger a read dynamic MAC table operation)
Then
Read reg. IADR1 (dynamic MAC table bits 71-64) // If bit 71 = 1, restart (reread) from this register
Read reg. IADR3 (dynamic MAC table bits 63-48)
Read reg. IADR2 (dynamic MAC table bits 47-32)
Read reg. IADR5 (dynamic MAC table bits 31-16)
Read reg. IADR4 (dynamic MAC table bits 15-0)
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VLAN Table
The KSZ8842M uses the VLAN table to perform look-ups. If 802.1Q VLAN mode is enabled (SGCR2[15]), this table will
be used to retrieve the VLAN information that is associated with the ingress packet. This information includes FID (filter
ID), VID (VLAN ID), and VLAN membership as described in Table 20:
Bit
Default Value
R/W
Description
19
1
RW
Valid
1: specifies that this entry is valid, the look up result will be used
0: specifies that this entry is not valid
18-16
111
R/W
Membership
Specifies 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. For example: 101 means port 3 and 1 are in
this VLAN.
15-12
0x0
R/W
FID
Specifies the Filter ID. The KSZ8842M supports 16 active VLANs represented by
these four bit fields. The FID is the mapped ID. If 802.1Q VLAN is enabled, the look
up will be based on FID+DA and FID+SA.
11-0
0x001
R/W
VID
Specifies the IEEE 802.1Q 12 bits VLAN ID.
Table 20. VLAN Table Format
If 802.1Q VLAN mode is enabled, KSZ8842M will assign 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 will be used. The look up process will start from the VLAN table look up. If the VID is not
valid, the packet will be dropped and no address learning will take place. 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 will be broadcast to all the members (excluding the ingress port) of the VLAN. If FID+SA fails, the FID+SA will be
learned.
VLAN Table Lookup Examples:
Examples:
1. VLAN Table Read (read the third entry, at the indirect address offset 0x02)
Write to reg. IACR with 0x1402 (set indirect address and trigger a read VLAN table operation)
Then
Read reg. IADR5 (VLAN table bits 19-16)
Read reg. IADR4 (VLAN table bits 15-0)
2. VLAN Table Write (write the seventh entry, at the indirect address offset 0x06)
Write to reg. IADR5 (VLAN table bits 19-16)
Write to reg. IADR4 (VLAN table bits 15-0)
Write to reg. IACR with 0x1406 (set indirect address and trigger a read VLAN table operation)
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Absolute Maximum Ratings(1)
Description
Pins
Value
Supply Voltage
VDDATX, VDDARX, VDDIO
–0.5V to 4.0V
Input Voltage
All Inputs
–0.5V to 5V
Output Voltage
All Outputs
–0.5V to 4.0V
Lead Temperature (soldering, 10 sec)
N/A
—
Storage Temperature (Ts)
N/A
–55°C to 150°C
Table 21. Maximum Ratings
Note:
1. Exceeding the absolute maximum rating may damage the device.
Stresses greater than those listed in the table above may cause permanent damage to the device. Operation of the device
at these or any other conditions above those specified in the operating sections of this specification is not implied.
Maximum conditions for extended periods may affect reliability. Unused inputs must always be tied to an appropriate logic
voltage level.
Operating Ratings(1)
Parameter
Symbol
Min
Typ
Max
Supply Voltages
VDDATX,VDDARX
3.1V
3.3V
3.5V
3.3V
3.5V
VDDIO
3.1V
Ambient Operating
Temperature
TA
0°C
Maximum Junction
Temperature
TJ
Thermal Resistance Junction to
(2)
Ambient
θJA
70°C
125°C
32°C/W
Table 22. Operating Ratings
Notes:
1. 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).
2. No (HS) heat spreader in this package.
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Electrical Characteristics(1)
Parameter
Symbol
Condition
Min
Typ
Max
Supply Current for 100BASE-TX Operation (All Ports@100% Utilization)
100BASE-TX
(analog core + PLL + digital core +
transceiver + digital I/O)
Iddxio
VDDATX, VDDARX, VDDIO = 3.3V
122mA
Supply Current for 10BASE-T Operation (All Ports@100% Utilization)
10BASE-T
(analog core + PLL + digital core +
transceiver + digital I/O)
Iddxio
VDDATX, VDDARX, VDDIO = 3.3V
90mA
TTL Inputs
Input High Voltage
Vih
Input Low Voltage
V
Input Current
Iin
Vin = GND ~ VDDIO
-10µA
Output High Voltage
Voh
Ioh = -8 mA
2.4V
Output Low Voltage
Vol
Iol = 8 mA
Output Tri-state Leakage
|Ioz|
2.0V
0.8V
il
10µA
TTL Outputs
0.4V
10µA
100Base-TX Transmit (measured differentially after 1:1 transformer)
Peak Differential Output Voltage
Vo
100Ω termination on the differential
output.
Output Voltage Imbalance
Vimb
100Ω termination on the differential
output
Rise/Fall Time
Tr/Tf
Rise/Fall Time Imbalance
+1.05V
+0.95V
2%
3ns
5ns
0ns
0.5ns
Duty Cycle Distortion
+
0.25ns
Overshoot
Reference Voltage of ISET
5%
Vset
Output Jitter
0.5V
Peak to peak
0.7ns
5MHz square wave
400mV
1.4ns
10Base-T Receive
Squelch Threshold
Vsq
10Base-T Transmit (measured differentially after 1:1 transformer)
Peak Differential Output Voltage
Vo
Output Jitter
100Ω termination on the differential
output
2.4V
Peak to peak
1.8ns
3.5ns
Note 1: TA = 25°C, specification for packaged product only
Table 23. Electrical Characteristics
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Timing Specifications
Asynchronous Timing without using Address Strobe (ADSN = 0)
t2
valid
Addr, AEN, BExN
ADSN
t3
t4
Read Data
valid
t1
t5
RDN, WRN
t6
Write Data
valid
t7
ARDY
(Read Cycle)
t9
t8
ARDY
( Write Cycle)
t10
Figure 16. Asynchronous Cycle – ADSN = 0
Symbol
Parameter
Min
Typ
Max
Unit
t1
A1-A15, AEN, BExN[3:0] valid to RDN, WRN active
2
ns
t2
A1-A15, AEN, BExN[3:0] hold after RDN, WRN
inactive (assume ADSN tied Low)
1
ns
t3
Read data valid to ARDY rising
t4
Read data to hold RDN inactive
4
ns
t5
Write data setup to WRN inactive
4
ns
t6
Write data hold after WRN inactive
2
ns
t7
Read active to ARDY Low
8
ns
t8
Write inactive to ARDY Low
8
ns
t9
ARDY low (wait time) in read cycle (Note1)
(It is 0ns to read bank select register)
(It is 110ns to read QMU data register)
ARDY low (wait time) in write cycle (Note1)
(It is 0ns to write bank select register)
(It is 85ns to write QMU data register)
t10
0.8
ns
0
110
ns
0
85
ns
Note1: When CPU finished current Read or Write operation, it can do next Read or Write operation even the
ARDY is low. During Read or Write operation if the ADRY is low, the CPU has to keep the RDN/WRN low until the
ARDY returns to high.
Table 24. Asynchronous Cycle (ADSN = 0) Timing Parameters
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Asynchronous Timing using Address Strobe (ADSN)
t8
valid
Addr, AEN, BExN
t6
ADSN
Read Data
valid
t1
t4
t3
RDN, WRN
t5
Write Data
valid
t7
ARDY
(Read Cycle)
t2
t10
t9
ARDY
( Write Cycle)
t11
Figure 17. Asynchronous Cycle – Using ADSN
Symbol
Parameter
Min
t1
A1-A15, AEN, BExN[3:0] valid to RDN, WRN active
t2
Read data valid to ARDY rising
t3
Read data hold to RDN inactive
Typ
Max
2
Unit
ns
0.8
4
ns
ns
t4
Write data setup to WRN inactive
4
ns
t5
Write data hold after WRN inactive
2
ns
t6
A1-A15, AEN, nBE[3:0] setup to ADSN rising
4
ns
t7
Read active to ARDY Low
8
t8
A1-A15, AEN, BExN[3:0] hold after ADSN rising
t9
Write inactive to ARDY Low
t10
ARDY low (wait time) in read cycle (Note1)
(It is 0ns to read bank select register)
(It is 110ns to read QMU data register)
ARDY low (wait time) in write cycle (Note1)
(It is 0ns to write bank select register)
(It is 85ns to write QMU data register)
t11
2
ns
ns
8
ns
0
110
ns
0
85
ns
Note1: When CPU finished current Read or Write operation, it can do next Read or Write operation even the
ARDY is low. During Read or Write operation if the ADRY is low, the CPU has to keep the RDN/WRN low until
the ARDY returns to high.
Table 25. Asynchronous Cycle using ADSN Timing Parameters
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Asynchronous Timing using DATACSN
t2
DATACSN
Read Data
valid
t1
t5
t4
RDN, WRN
t6
valid
Write Data
t7
ARDY
(Read Cycle)
t3
t9
t8
ARDY
( Write Cycle)
t10
Figure 18. Asynchronous Cycle – Using DATACSN
Symbol
Parameter
Min
Typ
Max
Unit
t1
DATACSN setup to RDN, WRN active
2
ns
t2
DATACSN hold after RDN, WRN inactive (assume
ADSN tied Low)
0
ns
t3
Read data hold to ARDY rising
t4
Read data to RDN hold
4
ns
t5
Write data setup to WRN inactive
4
ns
t6
Write data hold after WRN inactive
2
ns
t7
Read active to ARDY Low
8
ns
t8
Write inactive to ARDY Low
8
ns
t9
ARDY low (wait time) in read cycle (Note1)
(It is 0ns to read bank select register)
(It is 110ns to read QMU data register)
ARDY low (wait time) in write cycle (Note1)
(It is 0ns to write bank select register)
(It is 85ns to write QMU data register)
t10
0.8
ns
0
110
ns
0
85
ns
Note1: When CPU finished current Read or Write operation, it can do next Read or Write operation even the
ARDY is low. During Read or Write operation if the ADRY is low, the CPU has to keep the RDN/WRN low until
the ARDY returns to high.
Table 26. Asynchronous Cycle using DATACSN Timing Parameters
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Address Latching Timing for All Modes
t1
ADSN
t2
Address, AEN, BExN
t3
LDEVN
Figure 19. Address Latching Cycle for All Modes
Symbol
Parameter
Min
Typ
Max
Unit
t1
A1-A15, AEN, BExN[3:0] setup to ADSN
4
ns
t2
A1-A15, AEN, BExN[3:0] hold after ADSN rising
2
ns
t3
A4-A15, AEN to LDEVN delay
5
ns
Table 27. Address Latching Timing Parameters
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Synchronous Timing in Burst Write (VLBUSN = 1)
Figure 20. Synchronous Burst Write Cycles – VLBUSN = 1
Symbol
t1
Parameter
Min
SWR setup to BCLK falling
Typ
4
Max
Unit
ns
t2
DATDCSN setup to BCLK rising
4
ns
t3
CYCLEN setup to BCLK rising
4
ns
t4
Write data setup to BCLK rising
6
ns
t5
Write data hold to BCLK rising
2
ns
t6
RDYRTNN setup to BCLK falling
5
ns
t7
RDYRTNN hold to BCLK falling
3
ns
t8
SRDYN setup to BCLK rising
4
ns
t9
SRDYN hold to BCLK rising
3
ns
t10
DATACSN hold to BCLK rising
2
ns
t11
SWR hold to BCLK falling
2
ns
t12
CYCLEN hold to BCLK rising
2
ns
Table 28. Synchronous Burst Write Timing Parameters
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Synchronous Timing in Burst Read (VLBUSN = 1)
BCLK
t10
t2
DATACSN
t11
t1
SWR
t12
t3
CYCLEN
t5
t4
data0
Read Data
data1
data2
data3
t7
t6
RDYRTNN
t8
t9
SRDYN
Figure 21. Synchronous Burst Read Cycles – VLBUSN = 1
Symbol
t1
Parameter
Min
SWR setup to BCLK falling
Typ
4
Max
Unit
ns
t2
DATDCSN setup to BCLK rising
4
ns
t3
CYCLEN setup to BCLK rising
4
ns
t4
Read data setup to BCLK rising
6
ns
t5
Read data hold to BCLK rising
2
ns
t6
RDYRTNN setup to BCLK falling
5
ns
t7
RDYRTNN hold to BCLK falling
3
ns
t8
SRDYN setup to BCLK rising
4
ns
t9
SRDYN hold to BCLK rising
3
ns
t10
DATACSN hold to BCLK rising
2
ns
t11
SWR hold to BCLK falling
2
ns
t12
CYCLEN hold to BCLK rising
2
ns
Table 29. Synchronous Burst Read Timing Parameters
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Synchronous Write Timing (VLBUSN = 0)
BCLK
t2
Address, AEN, BExN
valid
t1
ADSN
t5
t6
SWR
t4
t3
CYCLEN
t7
Write Data
t8
valid
t9
t10
SRDYN
t11
t12
RDYRTNN
Figure 22. Synchronous Write Cycle – VLBUSN = 0
Symbol
Parameter
Min
Typ
Max
Unit
t1
A1-A15, AEN, BExN[3:0] setup to ADSN rising
4
ns
t2
A1-A15, AEN, BExN[3:0] hold after ADSN rising
2
ns
t3
CYCLEN setup to LCLK rising
4
ns
t4
CYCLEN hold after LCLK rising (non-burst mode)
2
ns
t5
SWR setup to BCLK
4
ns
t6
SWR hold after LCLK rising with SRDYN active
0
ns
t7
Write data setup to LCLK rising
5
ns
t8
Write data hold from LCLK rising
1
ns
t9
SRDYN setup to BCLK
8
ns
t10
SRDYN hold to BCLK
1
ns
t11
RDYRTNN setup to BCLK
4
ns
t12
RDYRTNN hold to BCLK
1
ns
Table 30. Synchronous Write (VLBUSN = 0) Timing Parameters
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Synchronous Read Timing (VLBUSN = 0)
BCLK
t2
Address, AEN, BExN
valid
t1
ADSN
t5
SWR
t4
t3
CYCLEN
t7
Read Data
t6
valid
t8
t9
SRDYN
t10
t11
RDYRTNN
Figure 23. Synchronous Read Cycle – VLBUSN = 0
Symbol
Parameter
Min
Typ
Max
Unit
t1
A1-A15, AEN, BExN[3:0] setup to ADSN rising
4
ns
t2
A1-A15, AEN, BExN[3:0] hold after ADSN rising
2
ns
t3
CYCLEN setup to LCLK rising
4
ns
t4
CYCLEN hold after LCLK rising (non-burst mode)
2
ns
t5
SWR setup to BCLK
4
ns
t6
Read data hold from LCLK rising
1
ns
t7
Read data setup to BCLK
8
ns
t8
SRDYN setup to BCLK
8
ns
t9
SRDYN hold to BCLK
1
ns
t10
RDYRTNN setup to LCLK rising
4
ns
t11
RDYRTNN hold after LCLK rising
1
ns
Table 31. Synchronous Read (VLBUSN = 0) Timing Parameters
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EEPROM Timing
EECS
*1
EESK
1
tcyc
EEDO
11
0
An
ts
A0
th
EEDI
High-Z
D15
D14
D1
D13
D0
*1 Start bit
Figure 24. EEPROM Read Cycle Timing Diagram
Timing
Parameter
Description
tcyc
Clock cycle
ts
Setup time
20
ns
th
Hold time
20
ns
Min
Typ
4
Max
Unit
µs
Table 32. EEPROM Timing Parameters
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Auto Negotiation Timing
Figure 25. Auto-Negotiation Timing
Timing
Parameter
Description
Min
Typ
Max
Unit
tBTB
FLP burst to FLP
burst
8
16
24
ms
tFLPW
FLP burst width
2
ms
tPW
Clock/Data pulse
width
100
ns
tCTD
Clock pulse to
data pulse
55.5
64
69.5
µs
tCTC
Clock pulse to
clock pulse
111
128
139
µs
Number of
Clock/Data
pulses per burst
17
33
Table 33. Auto Negotiation Timing Parameters
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Reset Timing
As long as the stable supply voltages to reset High timing (minimum of 10ms) are met, there is no power-sequencing
requirement for the KSZ8842M supply voltage (3.3V).
The reset timing requirement is summarized in the Figure 26 and Table 34.
Figure 26. Reset Timing
Symbol
Parameter
Min
tsr
Stable supply voltages to reset High
10
Max
Unit
ms
Table 34. Reset Timing Parameters
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Selection of Isolation Transformers
A 1:1 isolation transformer is required at the line interface. An isolation transformer with integrated common-mode choke
is recommended to exceed FCC requirements.
Table 35 gives recommended transformer characteristics.
Parameter
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
HIPOT (min)
1500Vrms
0MHz – 65MHz
Table 35. Transformer Selection Criteria
Magnetic Manufacturer
Part Number
Auto MDI-X
Number of Port
Pulse
H1102
Yes
1
Pulse (low cost)
H1260
Yes
1
Transpower
HB726
Yes
1
Bel Fuse
S558-5999-U7
Yes
1
Delta
LF8505
Yes
1
LanKom
LF-H41S
Yes
1
Table 36. Qualified Single Port Magnetic
Selection of Reference Crystal
Chacteristics
Value
Units
Frequency
25
MHz
Frequency tolerance (max)
±50
ppm
Load capacitance (max)
20
pF
Series resistance
25
Ω
Table 37. Typical Reference Crystal Characteristics
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Package Information
Figure 27. 128-Pin PQFP Package
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Figure 28. Optional 128-Pin LQFP Package
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Acronyms and Glossary
BIU
Bus Interface Unit
The host interface function that performs code conversion, buffering,
and the like required for communications to and from a network.
BPDU Bridge Protocol Data Unit
A packet containing ports, addresses, etc. to make sure data being
passed through a bridged network arrives at its proper destination.
CMOS Complementary Metal Oxide Semiconductor
A common semiconductor manufacturing technique in which positive
and negative types of transistors are combined to form a current gate
that in turn forms an effective means of controlling electrical current
through a chip.
CRC Cyclic Redundancy Check
A common technique for detecting data transmission errors. CRC for
Ethernet is 32 bits long.
Cut-through switch
A switch typically processes received packets by reading in the full
packet (storing), then processing the packet to determine where it
needs to go, then forwarding it. A cut-through switch simply reads in the
first bit of an incoming packet and forwards the packet. Cut-through
switches do not store the packet.
DA
The address to send packets.
Destination Address
DMA Direct Memory Access
A design in which memory on a chip is controlled independently of the
CPU.
EEPROM Electronically Erasable Programmable Read-only Memory
A design in which memory on a chip can be erased by exposing it to an
electrical charge.
EISA Extended Industry Standard Architecture
A bus architecture designed for PCs using 80x86 processors, or an Intel
80386, 80486 or Pentium microprocessor. EISA buses are 32 bits wide
and support multiprocessing.
A naturally occurring phenomena when the electromagnetic field of one
device disrupts, impedes or degrades the electromagnetic field of
another device by coming into proximity with it. In computer technology,
computer devices are susceptible to EMI because electromagnetic
fields are a byproduct of passing electricity through a wire. Data lines
that have not been properly shielded are susceptible to data corruption
by EMI.
EMI
Electro-Magnetic Interference
FCS
Frame Check Sequence
See CRC.
FID
Frame or Filter ID
Specifies the frame identifier. Alternately is the filter identifier.
IGMP Internet Group Management Protocol
The protocol defined by RFC 1112 for IP multicast transmissions.
IPG
Inter-Packet Gap
A time delay between successive data packets mandated by the
network standard for protocol reasons. In Ethernet, the medium has to
be "silent" (i.e., no data transfer) for a short period of time before a node
can consider the network idle and start to transmit. IPG is used to
correct timing differences between a transmitter and receiver. During
the IPG, no data is transferred, and information in the gap can be
discarded or additions inserted without impact on data integrity.
ISI
Inter-Symbol Interference
The disruption of transmitted code caused by adjacent pulses
affecting or interfering with each other.
ISA
Industry Standard Architecture
A bus architecture used in the IBM PC/XT and PC/AT.
Jumbo Packet
A packet larger than the standard Ethernet packet (1500 bytes). Large
packet sizes allow for more efficient use of bandwidth, lower overhead,
less processing, etc.
MDI
An Ethernet port connection that allows network hubs or switches to
connect to other hubs or switches without a null-modem, or crossover,
Medium Dependent Interface
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cable. MDI provides the standard interface to a particular media (copper
or fiber) and is therefore 'media dependent.'
MDI-X Medium Dependent Interface Crossover
An Ethernet port connection that allows networked end stations (i.e.,
PCs or workstations) to connect to each other using a null-modem, or
crossover, cable. For 10/100 full-duplex networks, an end point (such as
a computer) and a switch are wired so that each transmitter connects to
the far end receiver. When connecting two computers together, a cable
that crosses the TX and RX is required to do this. With auto MDI-X, the
PHY senses the correct TX and RX roles, eliminating any cable
confusion.
MIB
Management Information Base
The MIB comprises the management portion of network devices. This
can include things like monitoring traffic levels and faults (statistical),
and can also change operating parameters in network nodes (static
forwarding addresses).
MII
Media Independent Interface
The MII accesses PHY registers as defined in the IEEE 802.3
specification.
NIC
Network Interface Card
An expansion board inserted into a computer to allow it to be connected
to a network. Most NICs are designed for a particular type of network,
protocol, and media, although some can serve multiple networks.
NPVID Non Port VLAN ID
The Port VLAN ID value is used as a VLAN reference.
PLL
An electronic circuit that controls an oscillator so that it maintains a
constant phase angle (i.e., lock) on the frequency of an input, or
reference, signal. A PLL ensures that a communication signal is locked
on a specific frequency and can also be used to generate, modulate,
and demodulate a signal and divide a frequency.
Phase-Locked Loop
PME Power Management Event
An occurrence that affects the directing of power to different
components of a system.
QMU Queue Management Unit
Manages packet traffic between MAC/PHY interface and the system
host. The QMU has built-in packet memories for receive and transmit
functions called TXQ (Transmit Queue) and RXQ (Receive Queue).
SA
Source Address
TDR Time Domain Reflectometry
The address from which information has been sent.
TDR is used to pinpoint flaws and problems in underground and aerial
wire, cabling, and fiber optics. They send a signal down the conductor
and measure the time it takes for the signal -- or part of the signal -- to
return.
UTP
Commonly a cable containing 4 twisted pairs of wires. The wires are
twisted in such a manner as to cancel electrical interference generated
in each wire, therefore shielding is not required.
Unshielded Twisted Pair
VLAN Virtual Local Area Network
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A configuration of computers that acts as if all computers are connected
by the same physical network but which may be located virtually
anywhere.
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© 2005 Micrel, Incorporated.
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