Data Sheet
August 2011
Version 1.1
AR8031 Integrated 10/100/1000 Mbps Ethernet
Transceiver
General Description
The AR8031 is part of the Arctic family of
devices — which includes the AR8031, AR8033,
and AR8035. The AR8031 is Atheros’ 4th
generation, single port, 10/100/1000 Mbps, Trispeed Ethernet PHY. It supports both RGMII
and SGMII interfaces to the MAC.
The AR8031 provides a low power, low BOM
(Bill of Materials) cost solution for
comprehensive applications including
enterprise, carrier and home networks such as
CPE, home gateway, enterprise switch, carrier
switch/router, mobile base station and base
station controller, optical module and media
converter, industry automation and
measurement.
The AR8031 integrates Atheros Green ETHOS®
power saving technologies and significantly
saves power not only during the work time,
but also overtime. Atheros Green ETHOS®
power savings include ultra-low power in
cable unplugged mode or port power down
mode, and automatic optimized power saving
based on cable length. The AR8031 also
supports IEEE 802.3az EEE standard (Energy
Efficient Ethernet) and Atheros proprietary
SmartEEE. SmartEEE allows legacy MAC/SoC
devices without 802.3az support to function as
a complete 802.3az system. Further, the AR8031
supports Wake-on-LAN (WoL) feature to be
able to help manage and regulate total system
power requirements.
The AR8031 embeds CDT (Cable Diagnostics
Test) technology on-chip which allows
customers to measure cable length, detect the
cable status, and identify remote and local PHY
malfunctions, bad or marginal patch cord
segments or connectors. Some of the possible
problems that can be detected include opens,
shorts, cable impedance mismatch, bad
connectors, termination mismatch, and a bad
transformer.
The AR8031 requires only a single, 3.3V power
supply. On-chip regulators provide all the
other required voltages. It integrates the
termination R/C circuitry on both the MAC
interfaces (RGMII/SGMII) and the serial
resistors for the line side.
The AR8031 device also incorporates a 1.25
GHz SerDes. This interface can be connected
directly to a fiber-optic transceiver for 1000
BASE-X /100 BASE-FX mode or to MAC
device for SGMII interface.
The AR8031 supports both 1588v2 and
synchronous Ethernet to offer a complete time
synchronization solution to meet the next
generation network requirements. The key new
features supported by the device are:
n Clock synchronization between slave and
grandmaster by the exchange of PTP
packets. Supports IEEE 1588v2 by offering a
1588 paket parser, accurate time-stamping
and insertion to support both one-step and
two-step clock modes
n Supports both IEEE 1588v2 and
Synchronous Ethernet by offering recovered
clock output from data on the network-line
side.
The AR8031 supports IEEE 802.3az Energy
Efficient Ethernet (EEE) standard. The key
features supported by the device are:
n 10 BASE-Te PHY uses reduced transmit
amplitude.
n 100 BASE-TX and 1000 BASE-T use Low
Power Idle (LPI) mode to turn off unused
analog and digital blocks to save power
while data traffic is idle.
Features
n 10/100/1000 BASE-T IEEE 802.3 compliant
n Supports 1000 BASE-T PCS and auto-
negotiation with next page support
n Supports RGMII and/or SGMII interfaces
to MAC devices
n Supports Fiber and Copper combo mode
when MAC interface works in RGMII mode
n Supports additional IEEE 1000 BASE-X and
100 BASE-FX with Integrated SerDes
n RGMII timing modes support internal delay
and external delay on Rx path
© 2011 by Atheros Communications, Inc. All rights reserved. Atheros®, Atheros Driven®, Align®, Atheros XR®, Driving the Wireless Future®, Intellon®, No New Wires®,
Orion® , PLC4Trucks®, Powerpacket®, Spread Spectrum Carrier®, SSC®, ROCm®, Super A/G®, Super G®, Super N®, The Air is Cleaner at 5-GHz®, Total 802.11®, UNav®, Wake on Wireless®, Wireless Future. Unleashed Now.®, and XSPAN®, are registered by Atheros Communications, Inc. Atheros SST™, Signal-Sustain Technology™,
Ethos™, Install N Go™, IQUE™, ROCm™, amp™, Simpli-Fi™, There is Here™, U-Map™, U-Tag™, and 5-UP™ are trademarks of Atheros Communications, Inc. The
Atheros logo is a registered trademark of Atheros Communications, Inc. All other trademarks are the property of their respective holders. Subject to change without notice.
COMPANY CONFIDENTIAL
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n Supports Atheros Green ETHOS® power
n
n
n
n
n
n
n
saving modes with internal automatic DSP
power saving scheme
Supports IEEE 802.3az (Energy Efficient
Ethernet)
Supports SmartEEE which allows MAC/
SoC devices withoug 802.3az support to
function as the complete 802.3az system
Supports Wake-on-LAN (WoL) to detect
magic packet and notify the sleeping system
to wake up
Fully integrated digital adaptive equalizers,
echo cancellers, and Near End Crosstalk
(NEXT) cancellers
Supports Synchronous Ethernet with
selectable recovered clock output
Robust Cable Discharge Event (CDE)
protection of ±6 kV
Error-free operation over up to 140 meters
of CAT5 cable
n
n
n
n
n
n
n
n
n
n
n
Automatic channel swap (ACS)
Automatic MDI/MDIX crossover
Automatic polarity correction
IEEE 802.3u compliant Auto-Negotiation
Jumbo Frame support up to 10KB (full
duplex)
Multiple loopback modes for diagnostics
Robust Surge Protection with ±750 V/
differential mode and ±4 kV/common
mode
Cable Diagnostic Test (CDT)
Single power supply: 3.3V, optional for
external regulator for core voltage
6mm x 6mm, 48-pin QFN package
Industry temperature (I-temp) option
available.
AR8031 Functional Block Diagram
Symbol
Encoder
Waveshape
Filter
DAC
Echo
Canceller
PMA
TRD[0:3]
Hybrid
Circut
PGA
ADC
Decision
Feedback
Equalizer
Next
Canceller
Feed
Forward
Equalizer
Trellis
Decoder
Serial
Interface
Timing and
Phase
Recovery
2
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Symbol
Decoder
RGMII
Deskewer
AGC
AutoNegotiation
RGMII
MII Management
Registers
Sync-E
1588v2
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
SGMII/
SerDes
PCS
DLL
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
Revision History
Date
Revsion Details
Revision
2010/11/15
First draft
0.1
2011/4/14
General Description
n Overall update for revision from MPW to mass production
n Block diagram: add SYNC-E and 1588v2 block
Pin Descriptions
n RXD [3:0], RX_DV pin damping resistor 22ohm requirement is deleted.
n RST pin type change from "IH" to "I,” mass production chip does not have
internal weak PU
n INT, WOL_INT from "I/O active high" change to "D active low" need an
external PU
n Power on strapping LED_ACT from "1.1V/1.2V selection" to "PHY
ADDRESS [2]".
n LED_ACT/LED_LINK1000/LED_LINK10_100 from internal weak "PD"
change to internal weak "PU".
Functional Descriptions
n 2.2.4 Mode definition adds work mode"1011" combo mode.
Electrical Characteristics
n 3.1 Absolute Maximum Rating: update CDM max
n 3.2 Recommeded Operating Condition: update Tj max
n 3.7 Clock Characteristics: update values in Table 3-13 Recommended Crystal
Parameters
n Update Table 3-11 MDIO AC Characteristic to add tmdelay row
Register
n 4.2.29LED Control (0x18): update register bit definitions
n 4.2.30 Manual LED Override (0x19): new register
Topside Marking
n Add topside marking illustration
1.0
2011/8/29
Electrical Characteristics
n 3.2 Recommended Operation Conditions: delete DVDDL/AVDDL, JA; add
VDDH_REG, JT, AVDDL/DVDDL (industrial and commercial); add
thermal conditions
n 3.6 change title from MDIO DC Charateristics to MDIO/MDC DC...; change
VIH min value and VIL max value
1.1
n 3.7 table 3-14: change Jitterpk-pk max value to 100
n 3.11 Digital pin design guide (new)
Registers
n 4.2.3 Status Register – Copper page, change bit[8] reset value to always 1
n 4.3.4 Hib control and auto-neg test register: change bit[12], [6:5] to reserved
n 4.3.5 External loopback selection, change bit[0] to R/W
n 4.3.7 Power saving control (new)
n 4.4.75 SGMII Control register 2 (new)
n 4.4.76 SGMII Control register 3(new)
n 4.4.78 1588 RTC clock select register (new)
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver •
August 2011 •
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AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
Table of Contents
General Description ........................................ 1
Features ............................................................ 1
AR8031 Functional Block Diagram .............. 2
Revision History ............................................. 3
Table of Contents ............................................ 5
1 Pin Descriptions ............................ 9
1.1 Power-on Strapping Pins ...................... 13
1.1.1 Mode Definition .......................... 14
2 Functional Description ............... 15
2.2 Modes of Operation ............................... 16
2.2.1 Operation Mode, Copper .......... 16
2.2.2 Operation Mode, Fiber ............... 16
2.2.3 Operation Mode, Media Converter
17
2.2.4 Operation Mode, Auto-Media
Detect (Combo) ........................... 17
2.3 Transmit Functions ................................ 18
2.4 Receive Functions .................................. 18
2.4.1 Decoder Modes ........................... 18
2.4.2 Analog to Digital Converter ...... 18
2.4.3 Echo Canceller ............................. 18
2.4.4 NEXT Canceller .......................... 18
2.4.5 Baseline Wander Canceller ....... 18
2.4.6 Digital Adaptive Equalizer ....... 18
2.4.7 Auto-Negotiation ........................ 19
2.4.8 Smartspeed Function ................. 19
2.4.9 Automatic MDI/MDIX Crossover
19
2.4.10 Polarity Correction ..................... 19
2.5 Loopback Modes .................................... 19
2.5.1 Digital Loopback ......................... 19
2.5.2 External Cable Loopback ........... 19
2.5.3 Remote PHY Loopback .............. 20
2.6 Cable Diagnostic Test ............................ 20
2.7 Fiber Mode Support .............................. 20
2.7.1 IEEE 802.3 Remote Fault Indication
Support ......................................... 20
2.7.2 Fault Propagation ....................... 21
2.8 LED Interface .......................................... 21
2.9 Power Supplies ....................................... 22
2.10 Management Interface .......................... 24
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
2.11 Timing Sychronization ......................... 26
2.11.1 Synchronous Ethernet — Physical
Layer Timing Synchronization . 29
2.12 Atheros Green EthosTM ...................... 30
2.12.1 Low Power Modes ..................... 30
2.12.2 Shorter Cable Power Mode ....... 30
2.12.3 Hibernation Mode ...................... 30
2.13 IEEE 802.3az and Energy Efficient
Ethernet 30
2.14 IEEE 802.3az Energy Efficient Ethernet 30
2.14.1 IEEE 802.3az LPI Mode .............. 30
2.14.2 Atheros SmartEEE ...................... 31
2.15 Wake On LAN (WoL) .......................... 32
3 Electrical Characteristics ............33
3.1 Absolute Maximum Ratings ................ 33
3.2 Recommended Operating Conditions 33
3.3 RGMII Characteristics ........................... 34
3.4 SerDes and SGMII Characteristics ...... 37
3.5 MDIO Timing ......................................... 39
3.6 MDIO/MDC DC Characteristic .......... 39
3.7 Clock Characteristics ............................. 40
3.8 Power Pin Current Consumption ....... 41
3.9 Typical Power Consumption Parameters
41
3.10 Power-on Sequence, Reset and Clock 44
3.10.1 Power-on Sequence .................... 44
3.10.2 Reset and Clock Timing ............. 44
3.11 Digital Pin Design Guide ..................... 44
4 Register Descriptions ..................47
4.1 Register Summary ................................. 47
4.2 MII Registers .......................................... 47
4.2.1 Control Register — Copper Page 49
4.2.2 Control — Fiber Page ................. 50
4.2.3 Status Register — Copper Page 51
4.2.4 Status Register — Fiber Page .... 53
4.2.5 PHY Identifier ............................. 54
4.2.6 PHY Identifier2 ........................... 55
4.2.7 Auto-Negotiation Advertisement
Register — Copper Page ........... 55
4.2.8 Auto-Negotiation Advertisement
Register — Fiber Page ................ 57
4.2.9 Link Partner Ability Register —
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver •
August 2011 •
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4.2.10
4.2.11
4.2.12
4.2.13
4.2.14
4.2.15
4.2.16
4.2.17
4.2.18
4.2.19
4.2.20
4.2.21
4.2.22
4.2.23
4.2.24
4.2.25
4.2.26
4.2.27
4.2.28
4.2.29
4.2.30
4.2.31
4.2.32
4.2.33
4.2.34
4.2.35
Copper Page ................................ 58
Link Partner Ability Register —
Fiber Page .................................... 59
Auto-Negotiation Expansion
Register — Copper Page ............ 60
Auto-Negotiation Expansion
Register — Fiber Page ................ 61
Next Page Transmit Register —
Copper Page ................................ 62
Next Page Transmit Register —
Fiber Page for 1000 BASE-X, SGMII
62
Link Partner Next Page Register —
Copper Page ................................ 63
Link Partner Next Page Register —
Fiber Page for 1000 BASE-X, SGMII
64
1000 BASE-T Control Register .. 64
1000 BASE-T Status Register ..... 66
MMD Access Control Register . 67
MMD Access Address Data
Register ......................................... 67
Extended Status Register ........... 68
Function Control Register ......... 68
PHY-Specific Status Register —
Copper Page ................................ 69
PHY-Specific Status Register —
Fiber Page .................................... 71
Interrupt Enable Register .......... 72
Interrupt Status Register ............ 73
Smart Speed Register ................. 75
Cable Diagnostic Tester (CDT)
Control Register .......................... 76
LED Control ................................. 76
Manual LED Override Register 77
Copper/Fiber Status Register ... 78
Cable Diagnostic Tester Status
Register ......................................... 79
Debug Port (Address offset set) 80
Debug Port2 (R/W port) ............ 80
Chip Configure Register ............ 80
4.3 Debug Register Descriptions ................ 83
4.3.1 Analog Test Control ................... 83
4.3.2 SerDes Test and System Mode
Control .......................................... 83
4.3.3 100BASE-TX Test Mode Select .. 84
4.3.4 Hib Control and Auto-Negotiation
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Test Register ................................ 85
4.3.5 External Loopback Selection ..... 85
4.3.6 Test Configuration for 10BASE-T
85
4.3.7 Power Saving Control ................ 86
4.4 MDIO Interface Register ....................... 87
4.4.1 PCS Control ................................. 90
4.4.2 PCS Status .................................... 90
4.4.3 EEE Capability ............................ 91
4.4.4 EEE Wake Error Counter .......... 91
4.4.5 P1588 Control Register .............. 92
4.4.6 P1588 RX_seqid ........................... 93
4.4.7 P1588 rx_sourcePort_identity ... 93
4.4.8 P1588 rx_sourcePort_identity ... 93
4.4.9 P1588 rx_sourcePort_identity ... 93
4.4.10 P1588 rx_sourcePort_identity ... 94
4.4.11 P1588 rx_sourcePort_identity ... 94
4.4.12 P1588 rx_time_stamp ................. 94
4.4.13 P1588 rx_time_stamp ................. 94
4.4.14 P1588 rx_time_stamp ................. 95
4.4.15 P1588 rx_time_stamp ................. 95
4.4.16 P1588 rx_time_stamp ................. 95
4.4.17 P1588 Rx_frac_nano ................... 95
4.4.18 P1588 Rx_frac_nano ................... 96
4.4.19 P1588 Tx_seqid ........................... 96
4.4.20 P1588 tx_sourcePort_Identity ... 96
4.4.21 P1588 tx_sourcePort_Identity ... 96
4.4.22 P1588 tx_sourcePort_Identity ... 97
4.4.23 P1588 tx_sourcePort_Identity ... 97
4.4.24 P1588 tx_sourcePort_Identity ... 97
4.4.25 P1588 tx_sourcePort_Identity ... 97
4.4.26 P1588 tx_timestamp ................... 98
4.4.27 P1588 tx_timestamp ................... 98
4.4.28 P1588 tx_time_stamp ................. 98
4.4.29 P1588 tx_time_stamp ................. 98
4.4.30 P1588 tx_time_stamp ................. 98
4.4.31 P1588 Tx_frac_nano ................... 99
4.4.32 P1588 tx_frac_nano ..................... 99
4.4.33 P1588 Orgin_Correction_o ........ 99
4.4.34 P1588 Orgin_Correction_o ...... 100
4.4.35 P1588 Orgin_Correction_o ...... 100
4.4.36 P1588 Orgin_Correction_o ...... 100
4.4.37 P1588 Ingress_trig_time_o ...... 100
4.4.38 P1588 Ingress_trig_time_o ...... 100
4.4.39 P1588 Ingress_trig_time_o ...... 101
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
4.4.40
4.4.41
4.4.42
4.4.43
4.4.44
4.4.45
4.4.46
4.4.47
4.4.48
4.4.49
4.4.50
4.4.51
4.4.52
4.4.53
4.4.54
4.4.55
4.4.56
4.4.57
4.4.58
4.4.59
4.4.60
4.4.61
4.4.62
4.4.63
4.4.64
4.4.65
4.4.66
4.4.67
4.4.68
4.4.69
4.4.70
4.4.71
4.4.72
4.4.73
4.4.74
4.4.75
P1588 Ingress_trig_time_o ...... 101
P1588 Tx_latency_o .................. 101
P1588 Inc_value_o .................... 102
P1588 Inc_value_o .................... 102
P1588 Nano_offset_o ................ 102
P1588 Nano_offset_o ................ 102
P1588 Sec_offset_o .................... 103
P1588 Sec_offset_o .................... 103
P1588 Sec_offset_o .................... 103
P1588 Real_time_i ..................... 103
P1588 Real_time_i ..................... 103
P1588 Real_time_i ..................... 104
P1588 Real_time_i ..................... 104
P1588 Real_time_i ..................... 104
P1588 Rtc_frac_nano_i ............. 104
P1588 Rtc_frac_nano_i ............. 105
Wake-on-LAN Internal Address 1
105
Wake-on-LAN Internal Address 2
105
Wake-on-LAN Internal Address 3
105
Rem_phy_lpbk .......................... 106
SmartEEE Control 1 .................. 106
SmartEEE Control 2 .................. 106
SmartEEE control 3 ................... 107
Auto-Negotiation Control 1 .... 107
Auto-Negotiation Status .......... 108
Auto-Negotiation XNP Transmit .
108
Auto-Negotiation XNP transmit1
108
Auto-Negotiation XNP Transmit2
109
Auto-Negotiation LP XNP Ability
109
Auto-Negotiation LP XNP Ability1
109
Auto-Negotiation LP XNP ability2
109
EEE Advertisement .................. 110
EEE LP advertisement .............. 110
EEE Ability Auto-negotiation
Result .......................................... 111
SGMII Control Register 1 ........ 111
SGMII Control Register 2 ........ 112
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
4.4.76 SGMII Control Register 3 ........ 112
4.4.77 CLK_25M Clock Select ............ 112
4.4.78 1588 Clock Select ...................... 113
5 Package Dimensions .................115
6 Ordering Information ...............117
7 Topside Marking .......................117
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver •
August 2011 •
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AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
1. Pin Descriptions
This section contains a package pinout for the
AR8031 QFN 48 pin and a listing of the signal
descriptions (see Figure 1-1).
The following nomenclature is used for signal
types described in Table 1-1:
The following nomenclature is used for signal
names:
D
Open drain
IA
Analog input signal
NC
No connection to the internal die
is made from this pin
I
Digital input signal
n
At the end of the signal name,
indicates active low signals
IH
Input signals with weak internal
pull-up, to prevent signals from
floating when left open
P
At the end of the signal name,
indicates the positive side of a differential signal
IL
Input signals with weak internal
pull-down, to prevent signals
from floating when left open
N
At the end of the signal name
indicates the negative side of a
differential signal
I/O
A digital bidirectional signal
OA
An analog output signal
O
A digital output signal
P
A power or ground signal
PD
Internal pull-down for input
PU
Internal pull-up for input
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver •
August 2011 •
9
9
TXD1
TXD2
TXD3
WOL_INT
SD
SON
SOP
AVDDL
SIN
SIP
DVDDL
MDIO
Figure 1-1 shows the pinout diagram for AR8031.
48 47 46 45 44 43 42 41 40 39 38 37
MDC
1
36 TXD0
RSTn
2
35 GTX_CLK
LX
3
34 TX_EN
VDD33
4
33 RX_CLK
INT
5
XTLO
6
XTLI
7
AVDDL
8
RBIAS
9
AR8031
32 RX_DV
31 RXD0
TOP VIEW
30 RXD1
29 VDDIO_REG
28 RXD2
EXPOSED GROUND PAD ON
BOTTOM
VDDH_REG 10
27 RXD3
TRXP0 11
26 LED_LINK10_100
TRXN0 12
25 CLK_25M
LED_LINK1000
LED_ACT
PPS
TRXN3
TRXP3
AVDDL
TRXN2
TRXP2
AVDD33
TRXN1
TRXP1
AVDDL
13 14 15 16 17 18 19 20 21 22 23 24
Figure 1-1. AR8031 48-pin QFN Pinout Diagram (Top View)
NOTE: There is an exposed ground pad on the back side of the package.
10
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AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
Table 1-1. Signal to Pin Relationships and Descriptions
Symbol
Pin
Type
Description
TRXP0, TRXN0
11, 12
IA, OA
Media-dependent interface 0, differential 100 transmission line
TRXP1, TRXN1
14, 15
IA, OA
Media-dependent interface 1, differential 100 transmission line
TRXP2, TRXN2
17, 18
IA, OA
Media-dependent interface 2, differential 100 transmission line
TRXP3, TRXN3
20, 21
IA, OA
Media-dependent interface 3, differential 100 transmission line
GTX_CLK
35
I, PD
RX_CLK
33
I/O, PD
RGMII receive clock, 125 MHz at 1000 Mbps, 25 MHz at 100 Mbps,
and 2.5 MHz at 10 Mbps digital clock output
RX_DV
32
I/O, PD
RGMII receive data valid
RXD0
31
I/O, PD
RGMII receive data 0
RXD1
30
I/O, PD
RGMII receive data 1
RXD2
28
I/O, PD
RGMII receive data 2
RXD3
27
I/O, PD
RGMII receive data 3
TX_EN
34
I, PD
RGMII transmit enable
TXD0
36
I, PD
RGMII transmit data 0
TXD1
37
I, PD
RGMII transmit data 1
TXD2
38
I, PD
RGMII transmit data 2
TXD3
39
I, PD
RGMII transmit data 3
SIP/SIN
46, 45
IA
1.25 Gbps transmit differential inputs
When this interface is used as a MAC interface, the MAC
transmitter's positive output connects to SIP and the MAC
transmitter's negative output connects to the SIN.
When this interface is used as a fiber interface, the fiber-optic
transceiver's positive output connects to the SIP and the fiber-optic
transceiver's negative output connects to the SIN.
SOP/SON
43, 42
OA
1.25 Gbps receive differential outputs
When this interface is used as a MAC interface, the MAC receiver's
positive input connects to SOP and the MAC receiver's negative
input connects to the SON.
When this interface is used as a fiber interface, the fiber-optic
transceiver's positive input connects to the SOP and the fiber-optic
transceiver's negative input connects to the SON.
41
IA
Signal Detect. 1.2 V voltage level. Input signals must not exceed
1.4V.
MDI
RGMII
RGMII transmit clock, 125 MHz at 1000 Mbps, 25 MHz at 100
Mbps, and 2.5 MHz at 10 Mbps digital clock input
SGMII/1000FX
SD
Management Interface and Interrupt
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
•
•
11
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Table 1-1. Signal to Pin Relationships and Descriptions (continued)
Symbol
Pin
Type
Description
MDC
1
I, PU
Management data clock reference
MDIO
48
I/O, D, PU Management data, 1.5 kpull-up resistor to 3.3 V/ 2.5 V
LED
LED_ACT
23
I/O, PU
Parallel LED output for 10/100/1000 BASE-T activity; active
blinking LED active based upon power-on strapping. If pulled up,
active low; If pulled-down, active high
LED_LINK1000
24
I/O, PU
Parallel LED output for 1000 BASE-T link; LED active based upon
power-on strapping. If pulled up, active low; If pulled-down,
active high
LED_LINK10_100
26
I/O, PU
Parallel LED output for 10/100 BASE-T link. LED active based
upon power-on strapping of LED_LINK1000. If LED_LINK1000 is
pulled up, this pin is active low; if LED_LINK1000 is pulled-down,
this pin is active high.
High,
external
PU
10 Mbps
Low,
external
PU
100 Mbps
System Signal Group/Reference
CLK_25M
25
I/O
Synchronous Ethernet recovered clock (25MHz, 50MHz,
62.5MHzor 125MHz) output, register configurable, or IEEE 1588v2
reference 50 MHz- 125 MHz clock input.
RSTn
2
I
XTLI
7
IA
Crystal oscillator input; 27 pF capacitor to GND. Support external
25 MHz 1.2 V swing clock input through this pin.
XTLO
6
OA
Crystal oscillator output; 27 pF capacitor to GND
RBIAS
9
OA
External 2.37 k 1% resistor to GND to set bias current
INT
5
D, PD
System Interrupt Output. This pin is OD-gate by default and
requires external 10 k pull-up resistor, active low.
WOL_INT
40
D, PD
Wake-on-LAN interrupt output. This pin is OD-gate by default
and requires external 10 kresistor pull-up, active with a low
pulse of 32 link speed clock cycles. See “Wake On LAN (WoL)”
on page 32 for details.
LX
3
OA
Power inductor pin. Add an external 4.7 µH/500 mA power
inductor to this pin directly.
VDDH_REG
10
OA
2.5V regulator output.
VDDIO_REG
29
OA
Regulator output for the RGMII I/O voltage. It can be either 1.5V
(default) or 1.8V. If 2.5V is intended for the RGMII I/O, simply
connect this pin with the 2.5V regulator output at pin 10.
8, 13,
19, 44
P
System reset, active low. This pin requires an external pull-up
resistor.
Power
AVDDL
12
12
•
•
1.1V analog input. Connect to Pin 47 through a bead
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
Table 1-1. Signal to Pin Relationships and Descriptions (continued)
Symbol
Pin
Type
Description
DVDDL
47
P
1.1V digital core power input. Connect to power inductor directly
and 10uF+0.1uF ceramic capacitors to GND
VDD33
4
P
3.3V input for switching regulator
AVDD33
16
P
3.3V input for PHY, from VDD33 through a bead
22
O
IEEEv2 Pulse Per Second output. 1 Hz clock which is synchronous
with internal RTC.
1588v2 Pins
PPS
1.1 Power-on Strapping Pins
Table 1-2 shows the pin-to-PHY core Power-on strapping relationship
Table 1-2. Power-on Strapping Pins
PHY Pin
PHY Core Config
Signal
RXD0
PHYADDRESS0
RXD1
PHYADDRESS1
LED_ACT
PHYADDRESS2
Description
Default
Internal Weak
Pull-up/down
LED_ACT and RXD1-0 set the lower three bits of
the physical address. The upper two bits of the
physical address are set to the default, “00”.
0
0
1
RX_DV
MODE[0]
Mode select bit 0
0
RXD2
MODE[1]
Mode select bit 1
0
RX_CLK
MODE[2]
Mode select bit 2
0
RXD3
MODE[3]
Mode select bit 3
0
An external 10 k pull-down resistor is required
1
LED_LINK1000
INT SELECT
NOTE: 0 = Pull-down, 1 = Pull-up.
NOTE: Power-on strapping pins are latched during power-up reset or warm hardware reset.
NOTE: Since the MAC device input pins may be driven high or low during power-up or reset, PHY poweron strapping status may be affected by the MAC side. In this case an external 10 k pull-down or pull-up
resistor is required to ensure stable status.
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AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
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1.1.1 Mode Definition
Table 1-3 shows the Mode and its Description.
Table 1-3. Mode Definition
Mode [3:0]
Description
0000
1000 BASE-T, RGMII
0001
1000 BASE-T, SGMII
0010
1000 BASE-X, RGMII, 50
0011
1000 BASE-X, SGMII, 75
0100
Converter mode between 1000 BASE-X and 1000 BASE-T media, 50
0101
Converter mode between 1000 BASE-X and 1000 BASE-T media, 75
0110
100 BASE-FX, RGMII, 50
0111
Converter mode between 100 BASE-FX and 100 BASE-TX media, 50
1011
RGMII, copper fiber auto-detection
1110
100 BASE-FX, RGMII mode, 75
1111
Converter mode between 100 BASE-FX and 100 BASE-TX media, 75
Others
Reserved
NOTE: The 50 or 75 is the single end output impedance.
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AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
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2. Functional Description
Media-Independent Interface (RGMII) to
connect to a Gigabit-capable MAC.
The AR8031 is Atheros's low cost GbE PHY. It
is a highly integrated Analog Front End (AFE)
and digital signal transceiver, providing high
performance combined with substantial cost
reduction. The AR8031 provides physical layer
functions for half/full-duplex 10 BASE-Te, 100
BASE-TX and 1000 BASE-T Ethernet to
transmit and receive high-speed data over
standard Category 5 (CAT5) un-shielded
twisted pair cable.
The AR8031 transceiver combines echo
canceller, Near End Cross Talk (NEXT)
canceller, feed-forward equalizer, joint Viterbi,
feedback equalizer, and timing recovery, to
enhance signal performance in noisy
environments.
See “AR8031 Functional Block Diagram” on
page 2.
The AR8031 10/100/1000 PHY is fully 802.3ab
compliant, and supports Reduced Gigabit
Table 2-1 shows a feature comparison across the AR8031, AR8033, and AR8035 family.
Table 2-1. AR8031, AR8033, and AR8035 Comparison
Feature
AR8031
AR8033
AR8035
RGMII
yes
yes
yes
SGMII
yes
yes
Cu Ethernet**
yes
yes
yes
EEE (802.3az)
yes
yes
yes
Wake-on-LAN
yes
yes
yes
SERDES/Fiber***
yes
yes
1588v2
yes
Sync-E
yes
yes
48-pin
48-pin
Packaging
40-pin
NOTE: AR8031, AR8033 are pin-to-pin compatible.
** 10 BASE-Te, 100 BASE-TX, 1000 BASE-T are supported
*** 100BASE-FX, and 1000BASE-X are supported
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AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
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2.2 Modes of Operation
2.2.1 Operation Mode, Copper
The AR8031 operates in the following modes, as illustrated below:
Figure 2-1 shows the copper operating mode for AR8031.
SoC or
Switch
Transformer
MAC Interface
- RGMII
- SGMII
RJ-45
Media types:
- 10BASE-Te
- 100BASE-TX
- 1000BASE-T
AR8031
Figure 2-1. Operating Modes — Copper
SGMII is serial GMII interface which uses only 4 lines to connect with MAC/SOC. When copper-side
link is established, SGMII will pass the copper-side link status (link, speed, duplex) to MAC side for
building the link. SGMII interface shares the same SerDes with fiber port.
2.2.2 Operation Mode, Fiber
Figure 2-2 shows the fiber operating mode for AR8031.
SoC or
Switch
Fiber Optics
Fiber I/F
- Serial
MAC Interface
- RGMII
Media Types:
- 100BASE-FX
- 1000BASE-X
AR8031
Figure 2-2. Operating Modes — Fiber
AR8031 supports both 1000 BASE-X and 100 BASE-FX modes which are configured by power-on
strapping pins (see “Power-on Strapping Pins” on page 13) and by register 0x1F [3:0]. In fiber mode,
the MDI+/-[3:0] can be left floating.
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AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
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2.2.3 Operation Mode, Media Converter
Figure 2-3 shows the operating mode Media Converter for AR8031.
Fiber Interface:
SerDes
Transformer
Media Type:
- 100BASE-FX
- 1000BASE-X
RJ-45
Media Type:
- 100BASE-TX
- 1000BASE-T
AR8031
Figure 2-3. Operating Modes — Media Converter
AR8031 supports the following converter
modes:
2.2.4 Operation Mode, Auto-Media Detect
(Combo)
n 100 BASE-FX fiber to 100 BASE-TX copper
n 1000 BASE-X fiber to 1000 BASE-T copper
AR8031 supports auto-media detect feature
which allows MAC to detect active link
partners and process data from copper or fiber
interface according to the priority setting. The
copper and fiber work modes can be enabled
simultaneously by setting the mode bit to 1011
by power-on strapping pin or register 0x1F
[3:0].
Converter mode can be configured by poweron strapping (see “Power-on Strapping Pins”
on page 13). It can also be configured by
register 0x1F [3:0]. The register configuration
takes effect immediately. Three LEDs are used
to indicate fiber interface status.
In converter mode, auto-negotiation is running
independently on fiber and copper interfaces.
Link status can be checked from copper page
and fiber page respectively. Set 0x1F [15] to 1 to
select copper page, set 0x1F [15] to0 to select
fiber page. Offset address 0x0, 0x1, 0x4, 0x5,
0x6, 0x7, 0x8 and 0x11 refers to two register
pages respectively. See “Register Descriptions”
chapter for details.
When the fiber and copper interfaces link up to
the same speed, packets can go through the
PHY. When 1000M converter mode
(BX1000_CONV) is enabled, the copper port
can still link to 100M with a 100M link partner.
But packets can not go through the PHY.
NOTE: Since the two interfaces implement autonegotiation individually, controller is required to
ensure the duplex and pause of two remote link
partners are matched.
n No fiber or cable connection: Both interfaces
in power saving mode.
n Fiber connected: RGMII fiber mode. The
PHY uses external fiber signal detection
from the fiber module along with the
synchronization state machine to recognize
a valid connection.
n Copper connected: RGMII copper mode.
The PHY recognizes copper connection by
power transmitted over the copper line.
n Combo mode: When active link partners
over both fiber and copper are detected, the
PHY operation mode is defined by priority
setting. Priority is configured at register
0x1F [10] (0 = copper; 1 = fiber).
In auto media detect mode, fiber port can be
configured to 1000 BASE-X or 100 BASE-FX by
register 0x1F[8] (1 = 1000 BASE-X, default
setting; 0 = 100 BASE-FX).
In converter mode, the RGMII interface signal
can be left floating.
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AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
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2.3 Transmit Functions
2.4.2 Analog to Digital Converter
Table 2-2 describes the transmit function
encoder modes.
The AR8031 device employs an advanced high
speed ADC on each receive channel with high
resolution, which results in better SNR and
lower error rates.
Table 2-2. Transmit Function Encoder Modes
Encoder Mode Description
1000 BASE-T
In 1000 BASE-T mode, the AR8031
scrambles transmit data bytes
from the MAC interfaces to 9-bit
symbols and encodes them into
4D five-level PAM signals over the
four pairs of CAT5 cable.
100 BASE-TX
In 100 BASE-TX mode, 4-bit data
from the MII is 4B/5B serialized,
scrambled, and encoded to a
three-level MLT3 sequence
transmitted by the PMA.
10 BASE-Te
In 10 BASE-Te mode, the AR8031
transmits and receives
Manchester-encoded data.
2.4 Receive Functions
2.4.1 Decoder Modes
Table 2-3 describes the receive function
decoder modes.
Table 2-3. Receive Function Decoder Modes
Decoder Mode Description
1000 BASE-T
In 1000 BASE-T mode, the PMA
recovers the 4D PAM signals after
accounting for the cabling
conditions such as skew among
the four pairs, the pair swap order,
and the polarity of the pairs. The
resulting code group is decoded
into 8-bit data values. Data stream
delimiters are translated
appropriately and data is output
to the MAC interfaces.
100 BASE-TX
In 100 BASE-TX mode, the receive
data stream is recovered and
descrambled to align to the
symbol boundaries. The aligned
data is then parallelized and 5B/
4B decoded to 4-bit data. This
output runs to the MII receive
data pins after data stream
delimiters have been translated.
10 BASE-Te
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•
In 10 BASE-Te mode, the
recovered 10 BASE-Te signal is
decoded from Manchester then
aligned.
2.4.3 Echo Canceller
A hybrid circuit is used to transmit and receive
simultaneously on each pair. A signal reflects
back as an echo if the transmitter is not
perfectly matched to the line. Other connector
or cable imperfections, such as patch panel
discontinuity and variations in cable
impedance along the twisted pair cable, also
result in drastic SNR degradation on the
receive signal. The AR8031 device implements
a digital echo canceller to adjust for echo and is
adaptive to compensate for the varied channel
conditions.
2.4.4 NEXT Canceller
The 1000 BASE-T physical layer uses all four
pairs of wires to transmit data. Because the four
twisted pairs are bundled together, significant
high frequency crosstalk occurs between
adjacent pairs in the bundle. The AR8031
device uses three parallel NEXT cancellers on
each receive channel to cancel high frequency
crosstalk. The AR8031 cancels NEXT by
subtracting an estimate of these signals from
the equalizer output.
2.4.5 Baseline Wander Canceller
Baseline wander results from Ethernet links
that AC-couple to the transceivers and from
AC coupling that cannot maintain voltage
levels for longer than a short time. As a result,
transmitted pulses are distorted, resulting in
erroneous sampled values for affected pulses.
Baseline wander is more problematic in the
1000 BASE-T environment than in 100 BASETX due to the DC baseline shift in the transmit
and receive signals. The AR8031 device uses an
advanced baseline wander cancellation circuit
that continuously monitors and compensates
for this effect, minimizing the impact of DC
baseline shift on the overall error rate.
2.4.6 Digital Adaptive Equalizer
The digital adaptive equalizer removes intersymbol interference at the receiver. The digital
adaptive equalizer takes unequalized signals
from ADC output and uses a combination of
feedforward equalizer (FFE) and decision
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
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crossover algorithm as described in IEEE 802.3
clause 40.4.4 ensures that only one device
performs the required crossover.
feedback equalizer (DFE) for the bestoptimized signal-to-noise (SNR) ratio.
2.4.7 Auto-Negotiation
The AR8031 device supports 10/100/1000
BASE-T Copper auto-negotiation in accordance
with IEEE 802.3 clauses 28 and 40. Autonegotiation provides a mechanism for
transferring information between a pair of link
partners to choose the best possible mode of
operation in terms of speed, duplex modes,
and master/slave preference. Auto-negotiation
is initiated upon any of the following scenarios:
n Power-up reset
n Hardware reset
n Software reset
n Auto-negotiation restart
n Transition from power-down to power-up
n The link goes down
If auto-negotiation is disabled, a 10 BASE-Te or
100 BASE-TX can be manually selected using
the IEEE MII registers.
2.4.10 Polarity Correction
If cabling has been incorrectly wired, the
AR8031 automatically corrects polarity errors
on the receive pairs in 1000 BASE-T, 1000BASETX, and 10 BASE-Te modes.
2.5 Loopback Modes
2.5.1 Digital Loopback
Digital loopback provides the ability to loop
transmitted data back to the receiver using
digital circuitry in the AR8031 device. Figure 24 shows a block diagram of digital loopback.
MAC/
Switch
RGMII/
SGMII
PHY
Digital
PHY
AFE
NOTE: Smartspeed enable bit requires a software
reset to take effect after writing (write register
0x0[15]).
Figure 2-4. Digital Loopback
2.4.8 Smartspeed Function
The Atheros Smartspeed function is an
enhanced feature of auto-negotiation that
allows the AR8031 device to fall back in speed
based on cabling conditions as well as operate
over CAT3 cabling (in 10 BASE-T mode) or
two-pair CAT5 cabling (in 100 BASE-TX mode).
Followings are the register settings for
loopback mode selection:
By default, the Smartspeed feature is enabled.
Refer to the register “Smart Speed Register” on
page 75, which describes how to set the
parameters. Set these register bits to control the
Smartspeed feature:
n Bit [5]: 1 = Enables Smartspeed (default)
n Bits [4:2]: Sets the number of link attempts
before adjusting
n Bit [1]: Timer to determine the stable link
condition
2.5.2 External Cable Loopback
External cable loopback loops RGMII/SGMII
Tx to RGMII/SGMII Rx through a complete
digital and analog path and an external cable,
thus testing all the digital data paths and all the
analog circuits. Figure 2-5 shows a block
diagram of external cable loopback.
MAC/
Switch
RGMII
/SGMII
PHY
Digital
RJ‐45
NOTE: Smartspeed enable bit needs a software
reset (write register 0x0[15] = 1’b1 to take effect
after writing.
n 1000M loopback: register 0x0 = 0x4140
n 100M loopback: register 0x0 = 0x6100
n 10M loopback: register 0x0 = 0x4100
PHY
AFE
2.4.9 Automatic MDI/MDIX Crossover
During auto-negotiation, the AR8031 device
automatically determines and sets the required
MDI configuration, eliminating the need for
external crossover cable. If the remote device
also implements automatic MDI crossover, the
Atheros Communications, Inc.
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Figure 2-5. External Cable Loopback
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
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To configure external loopback:
1. Plug in an external loopback cable (1-3/2-6/
4-7/5-8).
2. Set debug register bit 0xB[15] to 0 to disable
hibernate (power saving) mode.
3. Set debug register bit 0x11[0] to 1 to enable
external loopback.
4. Set register 0x0 to select loopback modes:
– 1000M loopback: register 0x0 = 0x8140
– 100M loopback: register 0x0 = 0xA100
– 10M loopback: register 0x0 = 0x8100
NOTE: When cable is removed and then
reconnected to 1000M mode, the register 0x0
must be configured again to 0x8140 to establish
PHY link.
2.5.3 Remote PHY Loopback
Remote PHY loopback connects the MDI
receive path to the MDI transmit path, thus the
remote link partner can detect the connectivity
in the resulting loop.
MAC/
Switch
RGMII/
SGMII
PHY
Digital
PHY
AFE
RJ-45
Figure 2-6 shows a block diagram of external
cable loopback.
Figure 2-6. Remote PHY Loopback
To enable remote PHY loopback, set MMD3
register bit 0x805A[0] to 1.
NOTE: When remote loopback is enabled,
packets from link partner will still appear at
RGMII interface. Remote loopback is independent
of PHY auto-negotiation.
2.6 Cable Diagnostic Test
The Cable Diagnostic Test (CDT) feature in the
AR8031 device uses Time Domain
Reflectometry (TDR) to identify remote and
local PHY malfunctions, bad/marginal cable or
patch cord segments, or connectors. Some of
the possible problems that can be diagnosed
include opens, shorts, cable impedance
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•
•
mismatch, bad connectors, termination
mismatch, and bad magnetics. The CDT can be
performed when there is no link partner or
when the link partner is auto-negotiating.
To perform the cable diagnostic test:
1. Set register bits 0x16[9:8] to select the MDI
pair to be tested
2. Set register bit 0x16 to 1 to enable CDT
3. Check register bits 0x1C[9:8] for cable
failure status.
4. Check register bits 0x1C[7:0] for delta time.
The distance between the falure point and
PHY is [delta time] * 0.824.
2.7 Fiber Mode Support
Besides standard 10/100/1000 BASE-T copper
port support, Both AR8031 and AR8031
provide additional IEEE 1000 BASE-X and 100
BASE-FX support in fiber applications through
integrated SERDES. Both the AR8031 and the
AR8033 can work in RGMII mode to fiber or
10/100/1000 BASE-T to fiber.
Besides 1000 BASE-X and 100 BASE-FX
support, Both devices will support IEEE 802.3
remote Fault Indication and fault propagation
in fiber application.
2.7.1 IEEE 802.3 Remote Fault Indication
Support
Remote Fault allows stations on a fiber optic
link to know when there is a problem on the
link. Without Remote Fault, a station can not
detect a problem that affects only one fiber
(Transmit, for example).
With Remote Fault, the loss of a Receive signal
(Link) causes the Transmitter to send a special
pattern of data indicating that a fault has
occurred. 84 '1's followed by a single '0' is sent
three times, in-band, and is readily detectable
by the remote station, but is constructed so as
to not satisfy the 100BASE-X carrier sense
criterion, so the message will not be interpreted
as normal traffic. If the remote station has
Remote Fault, the link is dropped. If the remote
station does not have Remote Fault, the special
data pattern is ignored.
The AR8031 indicates whether or not a Remote
Fault pattern has been received from the
remote station using the "Remote Fault Status
Bit". This "Remote Fault Status Bit" can be
"Propagated" (see below) to the copper links on
both ends of a fiber link. In the event of a
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
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detected fault, both ends of the link can be
notified of the failure in this way. This is
particularly useful given the distances fiber
links are generally used over.
Figure 2-7 shows the Fiber Fault mechanism.
TwistedPair
Fiber
Fiber
Far-End-Fault or
Re-auto negotiation
TwistedPair
OFF
RX
TX
RX
TX
TX
RX
TX
RX
2.7.2 Fault Propagation
The AR8031 supports Fault Propagation - this
allows the fiber link fault to be propagated to
the Twisted-pair copper connections where the
"link down" status can be easily and quickly
detected.
The following steps describe Fault Propagation
(for both 100 BASE-FX and 1000 BASE-X):
The AR8031 supports Fault Propagation - this
allows the fiber link fault to be propagated to
the Twisted-pair copper connections where the
"link down" status can be easily and quickly
detected.
The following steps describe Fault Propagation
(for both 100 BASE-FX and 1000 BASE-X):
n The Twisted-pair transmit path will be OFF
n
n
n
n
n
when the Receive path of the Fiber link has
no signal detected or is link down. The two
Fiber media types are then handled as
described below:
The Media Converter (in 100 BASE-FX
mode) will transmit Far-End Fault message,
on the TX pair, when the Receive path of
Fiber has no signal detected or is link down.
This alerts the Media Converter on the
remote end of the link.
The Transmit Twisted-pair will then be
switched OFF on the remote end of the link.
The Media Converter (in 1000 BASE-X
mode) will restart auto-negotiation when
the Receive path of the Fiber detects no
signal or is link down.
Auto-negotiation will carry remote fault
indications from the Transmit fiber and the
local station will restart auto-negotiation
when its' Receive path has no detected
signal or is link down.
The Twisted-pair transmit path will be OFF
when the Receive path of a 1000 BASE-X
learns of the fault from an AN message.
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OFF
Figure 2-7. Fiber Fault Propagation or ReAuto-negotiation
2.8 LED Interface
The LED interface can either be controlled by
the PHY or controlled manually, independent
of the state of the PHY. The LEDs have three
status to indicate operation speed, traffic mode,
and link status. The LEDs can be programmed
to different status functions from their default
value.
Figure 2-8 and Figure 2-9 shows the references
designs for the LED interface.
AR8031
510
LED_ACT
470 pF
10 k
Figure 2-8. Reference Design for LED, Active
High
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August 2011
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VDDH_REG
AR8031
The active status of LED_ACT and
LED_LINK1000 depends on power-on
strapping mode. When the interface is
strapped high, the LED interface are active low;
when strapped low, active high. The active
status of LED_LINK10_100 depends on
LED_LINK1000 power-on strapping mode and
thus LED_LINK10_100 and LED_LINK1000
use the same LED reference design.
3.3 V
10 k
510
LED_ACT
470 pF
Figure 2-9. Reference Design for LED, Active
Low
Table 2-4. LED Status
Symbol
10M Link
10M Active
100M Link
100M Active
1000M Link
1000M Active
LED_LINK10_100
OFF
OFF
ON
ON
OFF
OFF
LED_LINK1000
OFF
OFF
OFF
OFF
ON
ON
LED_ACT
ON
BLINK
ON
BLINK
ON
BLINK
NOTE: ON = active; OFF = inactive
2.9 Power Supplies
The AR8031 device requires only one 3.3 V
external power supply. Internal power rails are
3.3 V, 2.5V, 1.1V and 1.8V/1.5V.
AR8031 integrates a switch regulator to convert
3.3V to 1.1V with high efficiency for core power
rail, thus external regulator is optional.
Two on-chip LDOs are integrated to support
2.5V/1.5V/1.8V RGMII I/O voltages. AR8031
can also work at 2.5 V RGMII I/O voltage and
3.3 V MAC RGMII interface. Since the input
can bear 3.3V logic signal, and the output logic
VoH and VoL can satisfy the 3.3V LVCMOS/
LVTTL requirement. Refer to “Electrical
Characteristics” for parameter details.
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August 2011
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
Figure 2-10 shows the reference design for 2.5V/3.3V RGMII voltage level:
AR8031
2.5V/3.3V
RGMII
Figure 2-10. Reference Design, 2.5 V/ 3.3 V RGMII I/O
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Figure 2-11 shows the reference design for 1.5/1.8 V RGMII voltage level.
AR8031
1.5/1.8V
RGMII
Figure 2-11. Reference Design, 1.5/1.8 V RGMII I/O
2.10 Management Interface
output bi-directional signal that runs
synchronously to MDC.
AR8031 integrates an MDC/MDIO
management interface in compliance with
IEEE802.3u clause 22.
MDIO is an OD-gate and requires an external
1.5k pull-up resistor.
Table 2-5 shows the structure of the
management frame.
MDC is input clock reference provided by the
MAC. MDIO is the management data input/
Table 2-5. Management Frame Fields
PRE
ST
OP
PHYAD REGAD
TA
DATA
IDLE
READ
1...1
01
10
AAAA
A
RRRRR
Z0
DDDDDDDDDDDDDDDD
Z
WRITE
1...1
01
01
AAAA
A
RRRRR
10
DDDDDDDDDDDDDDDD
Z
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AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
Table 2-6. Management Interface Field
Definitions
Field
Definition
PRE
A sequence of 32 contiguous single
logic bits on MDIO with
corresponding cycles on MDC to
provide PHY with a pattern to for
synchronization.
ST
Start of frame
OP
Operation code. 10 = read transaction,
01 = write transaction
PHYAD
PHY address. The 5-bit PHY address is
configured by power-on strapping.
Three address bits can be configured
in AR8031, thus eight PHYs can be
connected to a single management
interface. The PHYs connected to the
same bus has unique PHY addresses.
The first PHY address bit transmitted
and received is the MSB of the
address.
REGAD
Register address. The 5-bit register
address allows 32 registers to be
addressed at each PHY. The first
register address bit transmitted and
received is the MSB of the address.
TA
2-bit field to avoid contention during a
read operation.
In read operation, both MAC and PHY
are at high-impedance state for the
first bit time. The PHY drives a zero
during the second bit time of the
turnaround.
In write operation, the MAC must
drive 10.
DATA
16-bit data from accessed register.
MSN is transmitted first.
IDLE
High-impedance without driving state
of the MDIO. At least one clocked idle
state is required between frames.
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
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2.11 Timing Sychronization
IEEE 1588v2 provides a mechanism to
synchronize the clocks across an Ethernet
network by exchanging the IEEE 1588v2
packets. The slave node can adjust the local
clock based on the the timing information
calculated from timestamps exchanged. Figure
3-8 shows the top-level use of the AR8031 to
build a typical 1588v2 system. The AR8031
provides all the key componets to support an
IEEE 1588v2 operation. The IEEE 1588v2 Real
Time Clock (RTC) generates and provides time
information to other modules and software,
timing information includes Time of Day and
PPS. IEEE 1588v2 Control accepts control
information from software via MDC/MDIO,
generates control signals to other modules, and
provides status information to software.
IEEE1588v2 Timestamp Unit, packet detction
and processing, generates timestamps for IEEE
1588v2 event messages and interrupt signals
when receiving or transmitting IEEE 1588v2
messages. The AR8031 supports ordinary,
boundary and transparent clock modes as
defined in IEEE 1588v2 Figure 3-9 shows the
top level diagram of AR8031’s IEEE 1588v2
module. Also the AR8031 supports timestamps to be encapsulated into the 1588v2
packet as explained in the following figure.
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AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
Figure 2-12 Top Level Use of AR8031 in an IEEE 1588v2 system.
Hardware
AR8031
Line side
RTC
Software
RGMII/
SGMII
1588v2
module
OS
Controller
MAC
1588v2
Software
SMI
1588 ref. Local PPS
clock 25MHz
(optional)
Atheros Solution
Figure 2-12. Top Level Use of AR8031 in an IEEE 1588v2 System
Figure 2-13 shows the Top Level Diagram of the AR8031’s IEEE 1588v2 module.
1588v2 Module
Time of Day
IEEE 1588 Real
Time Clock
PPS
MDC/MDIO
RGMII/SGMII
IEEE 1588 Control
IEEE 1588
Timestamp Unit
Packet Detection
and Processing
Figure 2-13. Top Level Diagram of the AR8031’s IEEE 1588v2 Module
On the transmit side, the PHY will monitor and
parse the incoming packet from the top layer,
upon the request of sending IEEE 1588v2
packet, it will calculate the accurate time of
transmission onto the media and a timestamp
accordingly.
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
The AR8031 supports both one-step and twostep clock modes, as defined in IEEE 1588v2.
No matter where accurate time information is
carried — in the follow-up message (two-step
clock mode) or in the single event message
(one-step clock mode), the AR8031 will support
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
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correction filed update and CRC recalculation
on the fly.
n Delay_Req
On the receive side, the PHY will monitor and
parse the incoming packet from media, and
will generate a timestamp upon the reception
of IEEE 1588v2 packets. The built-in parser is
capable of detecting IEEE 1588v2 on ethernet
layer 2 (including untagged, one VLAN tagged
and two VLAN tagged), or layer 3 IPv4/UDP,
and IPv6/UDP (including PPPoE and SNAP).
Messages for the Peer Delay are also
supported:
The following IEEE 1588v2 packets are used to
exchange the timing message for the delay
request-response mechanism:
n Sync
n Delay_Resp
n Pdelay_Req
n Pdelay_Resp
n Pdelay_Resp_Follow_Up
The received IEEE 1588v2 packet along with
the timestamp will be forwarded to an external
CPU/MAC for further processing via
accelerated MDC/MDIO interfaces (running
up to 25MHz).
The AR8031 also supports time-stamp
encapsultion into the 1588v2 packet as
explained in the following figure 3-10.
n Follow_Up
Figure 2-14. PTP Timestamp.
L2/L3/L4 Header
L2/L3/L4 Header
PTP Message
PTP Message
0 or more Pads
0 or more Pads
CRC
Remove Old
CRC
Re-calculate CRC
Attached
timestamps
CRC
1. Event PTP message attach timestamp of itself.
2. General PTP message attach timestamp of associated
event PTP message if existed.
Figure 2-15. PTP Timestamp
AR8031 provides a Pulse Per Second output,
which locks onto the 1588v2 clock time of the
device.
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The AR8031 1588v2 logic allows multiple
reference clock sources, including:
n Local 25MHz crystal (default)
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
n Recovered clock from Sychronous Ethernet
n Dedicated, external 50MHz ~ 125MHz
1588v2 reference clock
The AR8031 IEEE 1588v2 module is under Tx
FIFO, so the FIFO does not affect time
stamping giving improved accuracy. Refer to
Figure 3-11 below.
Also, the IEEE 1588v2 module can be bypassed
by register settings.
Figure 2-16. Block Diagram of the AR8031 1588v2 module.
Rx
Tx
RGMII/SGMII
Tx FIFO
1588v2
IEEE 1588v2
module
miiswitch
Block Diagram:
IEEE 1588v2
Module
PCS
Rx
Tx
Figure 2-17. Block Diagram of the AR8031’s IEEE 1588v2 Module
2.11.1 Synchronous Ethernet — Physical
Layer Timing Synchronization
Atheros Communications, Inc.
COMPANY CONFIDENTIAL
The AR8031 supports Synchronous Ethernet
for 100BASE-TX and 1000BASE-T applications
AR8031 Integrated 10/100/1000 Mbps Ethernet Transceiver
August 2011
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by offering one recovered clock from the
network line-side. This recovered clock output
is register configurable to 25MHz (default),
50MHz, 62.5MHz or 125MHz, to meet the ITUT recommendations G.8261/Y.1361. The
network node can use this recovered clock to
replace local clock sources and drive the local
system. Therefore all distributed nodes the
network will use the same network clock to
support synchronus and timing sensitive
services like T1/E1 service over Ethernet.
See Table 4.4.77 on page 112 “Clock Select for
details.
2.12 Atheros Green EthosTM
2.12.1 Low Power Modes
The AR8031 device supports the software
power-down low power mode. The standard
IEEE power-down mode is entered by setting
the POWER_DOWN bit (bit [11]) of the register
“Control” on page 18 equal to one. In this
mode, the AR8031 ignores all MAC interface
signals except the MDC/MDIO. It does not
respond to any activity on the CAT 5 cable. The
AR8031 cannot wake up on its own. It can only
wake up by setting the POWER_DOWN bit of
the “Control” register to 0. .
2.12.2 Shorter Cable Power Mode
The AR8031 can attain an additional 25%
power savings when a cable length is detected
that is