DP83848IVVX [TI]
DP83848I PHYTER Industrial Temperature Single Port 10/100 Mb/s Ethernet Physical Layer Transceiver; DP83848I PHYTER工业温度单端口10/100 Mb / s以太网物理层收发器型号: | DP83848IVVX |
厂家: | TEXAS INSTRUMENTS |
描述: | DP83848I PHYTER Industrial Temperature Single Port 10/100 Mb/s Ethernet Physical Layer Transceiver |
文件: | 总86页 (文件大小:788K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
DP83848I
DP83848I PHYTER Industrial Temperature Single Port 10/100 Mb/s Ethernet
Physical Layer Transceiver
Literature Number: SNLS207E
May 2008
DP83848I PHYTER® - Industrial Temperature
Single Port 10/100 Mb/s Ethernet Physical Layer Transceiver
General Description
Features
The DP83848I is a robust fully featured 10/100 single
port Physical Layer device offering low power con-
sumption, including several intelligent power down
states. These low power modes increase overall prod-
uct reliability due to decreased power dissipation. Sup-
porting multiple intelligent power modes allows the
application to use the absolute minimum amount of
power needed for operation. In addition to low power,
the DP83848I is optimized for cable length perfor-
mance far exceeding IEEE specifications.
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Low-power 3.3V, 0.18µm CMOS technology
Low power consumption < 270mW Typical
3.3V MAC Interface
Auto-MDIX for 10/100 Mb/s
Energy Detection Mode
25 MHz clock out
SNI Interface (configurable)
RMII Rev. 1.2 Interface (configurable)
MII Serial Management Interface (MDC and MDIO)
IEEE 802.3u MII
The DP83848I includes a 25MHz clock out. This
means that the application can be designed with a
minimum of external parts, which in turn results in the
lowest possible total cost of the solution.
IEEE 802.3u Auto-Negotiation and Parallel Detection
IEEE 802.3u ENDEC, 10BASE-T transceivers and filters
IEEE 802.3u PCS, 100BASE-TX transceivers and filters
IEEE 1149.1 JTAG
The DP83848I easily interfaces to twisted pair media
via an external transformer and fully supports JTAG
IEEE specification 1149.1 for ease of manufacturing.
Additionally both MII and RMII are supported ensuring
ease and flexibility of design.
Integrated ANSI X3.263 compliant TP-PMD physical sub-
layer with adaptive equalization and Baseline Wander com-
pensation
The DP83848I features integrated sublayers to sup-
port both 10BASE-T and 100BASE-TX Ethernet proto-
cols, which ensures compatibility and interoperability
with all other standards based Ethernet solutions.
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Error-free Operation up to 150 meters
Programmable LED support Link, 10 /100 Mb/s Mode, Activ-
ity, and Collision Detect
The DP83848I is offered in a small form factor (48 pin
LQFP) so that a minimum of board space is needed.
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Single register access for complete PHY status
10/100 Mb/s packet BIST (Built in Self Test)
48-pin LQFP package (7mm) x (7mm)
Applications
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High End Peripheral Devices
Industrial Controls and Factory Automation
General Embedded Applications
System Diagram
10BASE-T
or
DP83848I
10/100 Mb/s
MPU/CPU
MII/RMII/SNI
100BASE-TX
25 MHz
Clock
Source
Status
LEDs
Typical Application
®
PHYTER is a registered trademark of National Semiconductor.
© 2008 National Semiconductor Corporation
www.national.com
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MII/RMII/SNI
SERIAL
MANAGEMENT
MII/RMII/SNI INTERFACES
RX_CLK
TX_DATA
TX_CLK
RX_DATA
MII
Registers
10BASE-T &
10BASE-T &
100BASE-TX
100BASE-TX
Auto-Negotiation
State Machine
Transmit
Block
Receive
Block
Clock
Generation
ADC
DAC
Boundary
Auto-MDIX
LED
Drivers
Scan
TD± RD±
LEDS
JTAG
REFERENCE CLOCK
Figure 1. DP83848I Functional Block Diagram
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1.0 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1 Serial Management Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
1.2 MAC Data Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
1.3 Clock Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
1.4 LED Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
1.5 JTAG Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
1.6 Reset and Power Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
1.7 Strap Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
1.8 10 Mb/s and 100 Mb/s PMD Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
1.9 Special Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
1.10 Power Supply Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
1.11 Package Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
2.0 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1 Auto-Negotiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
2.1.1 Auto-Negotiation Pin Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1.2 Auto-Negotiation Register Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1.3 Auto-Negotiation Parallel Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.4 Auto-Negotiation Restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.5 Enabling Auto-Negotiation via Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.6 Auto-Negotiation Complete Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2 Auto-MDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
2.3 PHY Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
2.3.1 MII Isolate Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.4 LED Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
2.4.1 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.4.2 LED Direct Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.5 Half Duplex vs. Full Duplex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
2.6 Internal Loopback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
2.7 BIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
3.0 Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.1 MII Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
3.1.1 Nibble-wide MII Data Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.1.2 Collision Detect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.1.3 Carrier Sense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.2 Reduced MII Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
3.3 10 Mb Serial Network Interface (SNI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
3.4 802.3u MII Serial Management Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
3.4.1 Serial Management Register Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.4.2 Serial Management Access Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.4.3 Serial Management Preamble Suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.0 Architecture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.1 100BASE-TX TRANSMITTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
4.1.1 Scrambler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.1.2 NRZ to NRZI Encoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.1.3 Binary to MLT-3 Convertor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.2 100BASE-TX RECEIVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
4.2.1 Analog Front End . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.2.2 Digital Signal Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.2.2.1 Digital Adaptive Equalization and Gain Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4.2.2.2 Base Line Wander Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.2.3 Signal Detect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.2.4 MLT-3 to NRZI Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.2.5 NRZI to NRZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.2.6 Serial to Parallel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.2.7 Descrambler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.2.8 Code-group Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.2.9 4B/5B Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.2.10 100BASE-TX Link Integrity Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.2.11 Bad SSD Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
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4.3 10BASE-T TRANSCEIVER MODULE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
4.3.1 Operational Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.3.2 Smart Squelch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.3.3 Collision Detection and SQE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.3.4 Carrier Sense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.3.5 Normal Link Pulse Detection/Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.3.6 Jabber Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3.7 Automatic Link Polarity Detection and Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3.8 Transmit and Receive Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3.9 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3.10 Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
5.0 Design Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
5.1 TPI Network Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
5.2 ESD Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
5.3 Clock In (X1) Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
5.4 Power Feedback Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
5.5 Power Down/Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
5.5.1 Power Down Control Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.5.2 Interrupt Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.6 Energy Detect Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
6.0 Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
6.1 Hardware Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
6.2 Software Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
7.0 Register Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.1 Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
7.1.1 Basic Mode Control Register (BMCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
7.1.2 Basic Mode Status Register (BMSR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
7.1.3 PHY Identifier Register #1 (PHYIDR1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
7.1.4 PHY Identifier Register #2 (PHYIDR2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
7.1.5 Auto-Negotiation Advertisement Register (ANAR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
7.1.6 Auto-Negotiation Link Partner Ability Register (ANLPAR) (BASE Page) . . . . . . . . . . . . . . . . 47
7.1.7 Auto-Negotiation Link Partner Ability Register (ANLPAR) (Next Page) . . . . . . . . . . . . . . . . . 48
7.1.8 Auto-Negotiate Expansion Register (ANER) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
7.1.9 Auto-Negotiation Next Page Transmit Register (ANNPTR) . . . . . . . . . . . . . . . . . . . . . . . . . . 49
7.2 Extended Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
7.2.1 PHY Status Register (PHYSTS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
7.2.2 MII Interrupt Control Register (MICR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
7.2.3 MII Interrupt Status and Misc. Control Register (MISR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
7.2.4 False Carrier Sense Counter Register (FCSCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
7.2.5 Receiver Error Counter Register (RECR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
7.2.6 100 Mb/s PCS Configuration and Status Register (PCSR) . . . . . . . . . . . . . . . . . . . . . . . . . . 55
7.2.7 RMII and Bypass Register (RBR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
7.2.8 LED Direct Control Register (LEDCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
7.2.9 PHY Control Register (PHYCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
7.2.10 10Base-T Status/Control Register (10BTSCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
7.2.11 CD Test and BIST Extensions Register (CDCTRL1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
7.2.12 Energy Detect Control (EDCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
8.0 Electrical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
8.1 DC Specs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
8.2 AC Specs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
8.2.1 Power Up Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
8.2.2 Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
8.2.3 MII Serial Management Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
8.2.4 100 Mb/s MII Transmit Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
8.2.5 100 Mb/s MII Receive Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
8.2.6 100BASE-TX Transmit Packet Latency Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
8.2.7 100BASE-TX Transmit Packet Deassertion Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
8.2.8 100BASE-TX Transmit Timing (tR/F & Jitter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
8.2.9 100BASE-TX Receive Packet Latency Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
8.2.10 100BASE-TX Receive Packet Deassertion Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
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4
8.2.11 10 Mb/s MII Transmit Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
8.2.12 10 Mb/s MII Receive Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
8.2.13 10 Mb/s Serial Mode Transmit Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
8.2.14 10 Mb/s Serial Mode Receive Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
8.2.15 10BASE-T Transmit Timing (Start of Packet) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
8.2.16 10BASE-T Transmit Timing (End of Packet) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
8.2.17 10BASE-T Receive Timing (Start of Packet) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
8.2.18 10BASE-T Receive Timing (End of Packet) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
8.2.19 10 Mb/s Heartbeat Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
8.2.20 10 Mb/s Jabber Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
8.2.21 10BASE-T Normal Link Pulse Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
8.2.22 Auto-Negotiation Fast Link Pulse (FLP) Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
8.2.23 100BASE-TX Signal Detect Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
8.2.24 100 Mb/s Internal Loopback Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
8.2.25 10 Mb/s Internal Loopback Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
8.2.26 RMII Transmit Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
8.2.27 RMII Receive Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
8.2.28 Isolation Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
8.2.29 25 MHz_OUT Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
8.2.30 100 Mb/s X1 to TX_CLK Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
9.0 Physical Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
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List of Figures
Figure 1. DP83848I Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Figure 2. PHYAD Strapping Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 3. AN Strapping and LED Loading Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 4. Typical MDC/MDIO Read Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 5. Typical MDC/MDIO Write Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 6. 100BASE-TX Transmit Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 7. 100BASE-TX Receive Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 8. EIA/TIA Attenuation vs. Frequency for 0, 50, 100, 130 & 150 meters of CAT 5 cable . . . . . . . . . . . 28
Figure 9. 100BASE-TX BLW Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 10. 10BASE-T Twisted Pair Smart Squelch Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Figure 11. 10/100 Mb/s Twisted Pair Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 12. Crystal Oscillator Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 13. Power Feeback Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
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6
List of Tables
Table 1. Auto-Negotiation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Table 2. PHY Address Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Table 3. LED Mode Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Table 4. Supported packet sizes at +/-50ppm +/-100ppm for each clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Table 5. Typical MDIO Frame Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Table 5. 4B5B CCode-group Encoding and Injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Table 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Table 7. 25 MHz Oscillator Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Table 8. 50 MHz Oscillator Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Table 9. 25 MHz Crystal Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Table 10. Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Table 11. Register Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Table 12. Basic Mode Control Register (BMCR), address 0x00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Table 13. Basic Mode Status Register (BMSR), address 0x01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Table 14. PHY Identifier Register #1 (PHYIDR1), address 0x02 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Table 15. PHY Identifier Register #2 (PHYIDR2), address 0x03 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Table 16. Negotiation Advertisement Register (ANAR), address 0x04 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Table 17. Auto-Negotiation Link Partner Ability Register (ANLPAR) (BASE Page), address 0x05 . . . . . . . .47
Table 18. Auto-Negotiation Link Partner Ability Register (ANLPAR) (Next Page), address 0x05 . . . . . . . . .48
Table 19. Auto-Negotiate Expansion Register (ANER), address 0x06 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Table 20. Auto-Negotiation Next Page Transmit Register (ANNPTR), address 0x07 . . . . . . . . . . . . . . . . . . .49
Table 21. PHY Status Register (PHYSTS), address 0x10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Table 22. MII Interrupt Control Register (MICR), address 0x11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Table 23. MII Interrupt Status and Misc. Control Register (MISR), address 0x12 . . . . . . . . . . . . . . . . . . . . . .53
Table 24. False Carrier Sense Counter Register (FCSCR), address 0x14 . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Table 25. Receiver Error Counter Register (RECR), address 0x15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Table 26. 100 Mb/s PCS Configuration and Status Register (PCSR), address 0x16 . . . . . . . . . . . . . . . . . . . .55
Table 27. RMII and Bypass Register (RBR), addresses 0x17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Table 28. LED Direct Control Register (LEDCR), address 0x18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Table 29. PHY Control Register (PHYCR), address 0x19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Table 30. 10Base-T Status/Control Register (10BTSCR), address 0x1A . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Table 31. CD Test and BIST Extensions Register (CDCTRL1), address 0x1B . . . . . . . . . . . . . . . . . . . . . . . . .60
Table 32. Energy Detect Control (EDCR), address 0x1D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
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Pin Layout
37
24
23
RBIAS
PFBIN2
PFBOUT
AVDD33
RESERVED
RESERVED
AGND
RX_CLK
38
39
40
41
RX_DV/MII_MODE
CRS/CRS_DV/LED_CFG
RX_ER/MDIX_EN
COL/PHYAD0
22
21
20
19
42
43
44
45
46
47
48
DP83848I
PFBIN1
TD +
RXD_0/PHYAD1
RXD_1/PHYAD2
RXD_2/PHYAD3
RXD_3/PHYAD4
IOGND
18
17
16
15
14
13
TD -
AGND
RD +
RD -
IOVDD33
o
Top View
NS Package Number VBH48A
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8
1.0 Pin Descriptions
The DP83848I pins are classified into the following inter- Note: Strapping pin option. Please see Section 1.7 for strap
face categories (each interface is described in the sections
that follow):
definitions.
All DP83848I signal pins are I/O cells regardless of the par-
ticular use. The definitions below define the functionality of
the I/O cells for each pin.
— Serial Management Interface
— MAC Data Interface
— Clock Interface
Type: I
Input
— LED Interface
Type: O
Type: I/O
Type OD
Output
— JTAG Interface
Input/Output
Open Drain
— Reset and Power Down
— Strap Options
Type: PD,PU Internal Pulldown/Pullup
Type: S Strapping Pin (All strap pins have weak in-
— 10/100 Mb/s PMD Interface
— Special Connect Pins
— Power and Ground pins
ternal pull-ups or pull-downs. If the default
strap value is needed to be changed then an
external 2.2 kΩ resistor should be used.
Please see Section 1.7 for details.)
1.1 Serial Management Interface
Signal Name
Type
Pin #
Description
MDC
I
31
MANAGEMENT DATA CLOCK: Synchronous clock to the MDIO
management data input/output serial interface which may be
asynchronous to transmit and receive clocks. The maximum clock
rate is 25 MHz with no minimum clock rate.
MDIO
I/O
30
MANAGEMENT DATA I/O: Bi-directional management instruc-
tion/data signal that may be sourced by the station management
entity or the PHY. This pin requires a 1.5 kΩ pullup resistor.
1.2 MAC Data Interface
Signal Name
Type
Pin #
Description
TX_CLK
O
1
MII TRANSMIT CLOCK: 25 MHz Transmit clock output in 100
Mb/s mode or 2.5 MHz in 10 Mb/s mode derived from the 25 MHz
reference clock.
Unused in RMII mode. The device uses the X1 reference clock in-
put as the 50 MHz reference for both transmit and receive.
SNI TRANSMIT CLOCK: 10 MHz Transmit clock output in 10 Mb
SNI mode. The MAC should source TX_EN and TXD_0 using this
clock.
TX_EN
I, PD
2
MII TRANSMIT ENABLE: Active high input indicates the pres-
ence of valid data inputs on TXD[3:0].
RMII TRANSMIT ENABLE: Active high input indicates the pres-
ence of valid data on TXD[1:0].
SNI TRANSMIT ENABLE: Active high input indicates the pres-
ence of valid data on TXD_0.
TXD_0
TXD_1
TXD_2
TXD_3
I
3
4
5
6
MII TRANSMIT DATA: Transmit data MII input pins, TXD[3:0],
that accept data synchronous to the TX_CLK (2.5 MHz in 10 Mb/s
mode or 25 MHz in 100 Mb/s mode).
RMII TRANSMIT DATA: Transmit data RMII input pins, TXD[1:0],
that accept data synchronous to the 50 MHz reference clock.
S, I, PD
SNI TRANSMIT DATA: Transmit data SNI input pin, TXD_0, that
accept data synchronous to the TX_CLK (10 MHz in 10 Mb/s SNI
mode).
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Signal Name
RX_CLK
Type
Pin #
Description
O
38
MII RECEIVE CLOCK: Provides the 25 MHz recovered receive
clocks for 100 Mb/s mode and 2.5 MHz for 10 Mb/s mode.
Unused in RMII mode. The device uses the X1 reference clock in-
put as the 50 MHz reference for both transmit and receive.
SNI RECEIVE CLOCK: Provides the 10 MHz recovered receive
clocks for 10 Mb/s SNI mode.
RX_DV
RX_ER
S, O, PD
S, O, PU
39
41
MII RECEIVE DATA VALID: Asserted high to indicate that valid
data is present on the corresponding RXD[3:0]. MII mode by de-
fault with internal pulldown.
RMII Synchronous Receive Data Valid: This signal provides the
RMII Receive Data Valid indication independent of Carrier Sense.
This pin is not used in SNI mode.
MII RECEIVE ERROR: Asserted high synchronously to RX_CLK
to indicate that an invalid symbol has been detected within a re-
ceived packet in 100 Mb/s mode.
RMII RECEIVE ERROR: Assert high synchronously to X1 when-
ever it detects a media error and RXDV is asserted in 100 Mb/s
mode.
This pin is not required to be used by a MAC, in either MII or RMII
mode, since the Phy is required to corrupt data on a receive error.
This pin is not used in SNI mode.
RXD_0
RXD_1
RXD_2
RXD_3
S, O, PD
S, O, PU
S, O, PU
43
44
45
46
MII RECEIVE DATA: Nibble wide receive data signals driven syn-
chronously to the RX_CLK, 25 MHz for 100 Mb/s mode, 2.5 MHz
for 10 Mb/s mode). RXD[3:0] signals contain valid data when
RX_DV is asserted.
RMII RECEIVE DATA: 2-bits receive data signals, RXD[1:0], driv-
en synchronously to the X1 clock, 50 MHz.
SNI RECEIVE DATA: Receive data signal, RXD_0, driven syn-
chronously to the RX_CLK. RXD_0 contains valid data when CRS
is asserted. RXD[3:1] are not used in this mode.
CRS/CRS_DV
40
MII CARRIER SENSE: Asserted high to indicate the receive me-
dium is non-idle.
RMII CARRIER SENSE/RECEIVE DATA VALID: This signal
combines the RMII Carrier and Receive Data Valid indications.
For a detailed description of this signal, see the RMII Specifica-
tion.
SNI CARRIER SENSE: Asserted high to indicate the receive me-
dium is non-idle. It is used to frame valid receive data on the
RXD_0 signal.
COL
42
MII COLLISION DETECT: Asserted high to indicate detection of
a collision condition (simultaneous transmit and receive activity)
in 10 Mb/s and 100 Mb/s Half Duplex Modes.
While in 10BASE-T Half Duplex mode with heartbeat enabled this
pin is also asserted for a duration of approximately 1µs at the end
of transmission to indicate heartbeat (SQE test).
In Full Duplex Mode, for 10 Mb/s or 100 Mb/s operation, this sig-
nal is always logic 0. There is no heartbeat function during 10
Mb/s full duplex operation.
RMII COLLISION DETECT: Per the RMII Specification, no COL
signal is required. The MAC will recover CRS from the CRS_DV
signal and use that along with its TX_EN signal to determine col-
lision.
SNI COLLISION DETECT: Asserted high to indicate detection of
a collision condition (simultaneous transmit and receive activity)
in 10 Mb/s SNI mode.
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10
1.3 Clock Interface
Signal Name
Type
Pin #
Description
X1
I
34
CRYSTAL/OSCILLATOR INPUT: This pin is the primary clock
reference input for the DP83848I and must be connected to a 25
MHz 0.005% (+50 ppm) clock source. The DP83848I supports ei-
ther an external crystal resonator connected across pins X1 and
X2, or an external CMOS-level oscillator source connected to pin
X1 only.
RMII REFERENCE CLOCK: This pin is the primary clock refer-
ence input for the RMII mode and must be connected to a 50 MHz
0.005% (+50 ppm) CMOS-level oscillator source.
X2
O
O
33
25
CRYSTAL OUTPUT: This pin is the primary clock reference out-
put to connect to an external 25 MHz crystal resonator device.
This pin must be left unconnected if an external CMOS oscillator
clock source is used.
25MHz_OUT
25 MHz CLOCK OUTPUT:
In MII mode, this pin provides a 25 MHz clock output to the sys-
tem.
In RMII mode, this pin provides a 50 MHz clock output to the sys-
tem.
This allows other devices to use the reference clock from the
DP83848I without requiring additional clock sources.
1.4 LED Interface
See Table 3 for LED Mode Selection.
Signal Name
LED_LINK
Type
Pin #
Description
S, O, PU
28
LINK LED: In Mode 1, this pin indicates the status of the LINK.
The LED will be ON when Link is good.
LINK/ACT LED: In Mode 2 and Mode 3, this pin indicates transmit
and receive activity in addition to the status of the Link. The LED
will be ON when Link is good. It will blink when the transmitter or
receiver is active.
LED_SPEED
S, O, PU
S, O, PU
27
26
SPEED LED: The LED is ON when device is in 100 Mb/s and OFF
when in 10 Mb/s. Functionality of this LED is independent of mode
selected.
LED_ACT/COL
ACTIVITY LED: In Mode 1, this pin is the Activity LED which is
ON when activity is present on either Transmit or Receive.
COLLISION/DUPLEX LED: In Mode 2, this pin by default indi-
cates Collision detection. For Mode 3, this LED output may be
programmed to indicate Full-duplex status instead of Collision.
11
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1.5 JTAG Interface
Signal Name
Type
Pin #
Description
TCK
I, PU
8
TEST CLOCK
This pin has a weak internal pullup.
TEST DATA INPUT
TDI
I, PU
12
This pin has a weak internal pullup.
TEST OUTPUT
TDO
TMS
O
9
I, PU
10
TEST MODE SELECT
This pin has a weak internal pullup.
TEST RESET: Active low asynchronous test reset.
This pin has a weak internal pullup.
TRST#
I, PU
11
1.6 Reset and Power Down
Signal Name
Type
Pin #
Description
RESET_N
I, PU
29
RESET: Active Low input that initializes or re-initializes the
DP83848I. Asserting this pin low for at least 1 µs will force a reset
process to occur. All internal registers will re-initialize to their de-
fault states as specified for each bit in the Register Block section.
All strap options are re-initialized as well.
PWR_DOWN/INT
I, OD, PU
7
See Section 5.5 for detailed description.
The default function of this pin is POWER DOWN.
POWER DOWN: The pin is an active low input in this mode and
should be asserted low to put the device in a Power Down mode.
INTERRUPT: The pin is an open drain output in this mode and will
be asserted low when an interrupt condition occurs. Although the
pin has a weak internal pull-up, some applications may require an
external pull-up resister. Register access is required for the pin to
be used as an interrupt mechanism. See Section 5.5.2 Interrupt
Mechanism for more details on the interrupt mechanisms.
1.7 Strap Options
A 2.2 kΩ resistor should be used for pull-down or pull-up to
change the default strap option. If the default option is
required, then there is no need for external pull-up or pull
down resistors. Since these pins may have alternate func-
tions after reset is deasserted, they should not be con-
nected directly to VCC or GND.
The DP83848I uses many of the functional pins as strap
options. The values of these pins are sampled during reset
and used to strap the device into specific modes of opera-
tion. The strap option pin assignments are defined below.
The functional pin name is indicated in parentheses.
Signal Name
PHYAD0 (COL)
Type
Pin #
42
Description
S, O, PU
S, O, PD
PHY ADDRESS [4:0]: The DP83848I provides five PHY address
pins, the state of which are latched into the PHYCTRL register at
system Hardware-Reset.
PHYAD1 (RXD_0)
PHYAD2 (RXD_1)
PHYAD3 (RXD_2)
PHYAD4 (RXD_3)
43
44
The DP83848I supports PHY Address strapping values 0
(<00000>) through 31 (<11111>). A PHY Address of 0 puts the
part into the MII Isolate Mode. The MII isolate mode must be se-
lected by strapping Phy Address 0; changing to Address 0 by reg-
ister write will not put the Phy in the MII isolate mode. Please refer
to section 2.3 for additional information.
45
46
PHYAD0 pin has weak internal pull-up resistor.
PHYAD[4:1] pins have weak internal pull-down resistors.
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Signal Name
AN_EN (LED_ACT/COL)
AN_1 (LED_SPEED)
AN_0 (LED_LINK)
Type
Pin #
26
Description
S, O, PU
Auto-Negotiation Enable: When high, this enables Auto-Negoti-
ation with the capability set by ANO and AN1 pins. When low, this
puts the part into Forced Mode with the capability set by AN0 and
AN1 pins.
27
28
AN0 / AN1: These input pins control the forced or advertised op-
erating mode of the DP83848I according to the following table.
The value on these pins is set by connecting the input pins to
GND (0) or VCC (1) through 2.2 kΩ resistors. These pins should
NEVER be connected directly to GND or VCC.
The value set at this input is latched into the DP83848I at Hard-
ware-Reset.
The float/pull-down status of these pins are latched into the Basic
Mode Control Register and the Auto_Negotiation Advertisement
Register during Hardware-Reset.
The default is 111 since these pins have internal pull-ups.
AN_EN AN1 AN0
Forced Mode
0
0
0
0
0
0
1
1
0
1
0
1
10BASE-T, Half-Duplex
10BASE-T, Full-Duplex
100BASE-TX, Half-Duplex
100BASE-TX, Full-Duplex
Advertised Mode
AN_EN AN1 AN0
1
1
1
0
0
1
0
1
0
10BASE-T, Half/Full-Duplex
100BASE-TX, Half/Full-Duplex
10BASE-T Half-Duplex
100BASE-TX, Half-Duplex
10BASE-T, Half/Full-Duplex
100BASE-TX,Half/Full-Duplex
1
1
1
MII_MODE (RX_DV)
SNI_MODE (TXD_3)
S, O, PD
39
6
MII MODE SELECT: This strapping option pair determines the
operating mode of the MAC Data Interface. Default operation (No
pull-ups) will enable normal MII Mode of operation. Strapping
MII_MODE high will cause the device to be in RMII or SNI mode
of operation, determined by the status of the SNI_MODE strap.
Since the pins include internal pull-downs, the default values are
0.
The following table details the configurations:
MII_MODE SNI_MODE
MAC Interface
Mode
0
1
1
X
0
1
MII Mode
RMII Mode
10 Mb SNI Mode
LED_CFG (CRS)
S, O, PU
S, O, PU
40
41
LED CONFIGURATION: This strapping option determines the
mode of operation of the LED pins. Default is Mode 1. Mode 1 and
Mode 2 can be controlled via the strap option. All modes are con-
figurable via register access.
SeeTable 3 for LED Mode Selection.
MDIX_EN (RX_ER)
MDIX ENABLE: Default is to enable MDIX. This strapping option
disables Auto-MDIX. An external pull-down will disable Auto-
MDIX mode.
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1.8 10 Mb/s and 100 Mb/s PMD Interface
Signal Name
TD-, TD+
Type
Pin #
Description
I/O
16, 17
Differential common driver transmit output (PMD Output Pair).
These differential outputs are automatically configured to either
10BASE-T or 100BASE-TX signaling.
In Auto-MDIX mode of operation, this pair can be used as the Re-
ceive Input pair.
These pins require 3.3V bias for operation.
RD-, RD+
I/O
13, 14
Differential receive input (PMD Input Pair). These differential in-
puts are automatically configured to accept either 100BASE-TX
or 10BASE-T signaling.
In Auto-MDIX mode of operation, this pair can be used as the
Transmit Output pair.
These pins require 3.3V bias for operation.
1.9 Special Connections
Signal Name
Type
Pin #
Description
RBIAS
I
24
Bias Resistor Connection. A 4.87 kΩ 1% resistor should be con-
nected from RBIAS to GND.
PFBOUT
O
I
23
Power Feedback Output. Parallel caps, 10µ F (Tantalum pre-
ferred) and 0.1µF, should be placed close to the PFBOUT. Con-
nect this pin to PFBIN1 (pin 18) and PFBIN2 (pin 37). See
Section 5.4 for proper placement pin.
PFBIN1
PFBIN2
18
37
Power Feedback Input. These pins are fed with power from
PFBOUT pin. A small capacitor of 0.1µF should be connected
close to each pin.
Note: Do not supply power to these pins other than from
PFBOUT.
RESERVED
I/O
20, 21
RESERVED: These pins must be pulled-up through 2.2 kΩ resis-
tors to AVDD33 supply.
1.10 Power Supply Pins
Signal Name
IOVDD33
IOGND
Pin #
Description
I/O 3.3V Supply
32, 48
35, 47
36
I/O Ground
DGND
Digital Ground
AVDD33
22
Analog 3.3V Supply
Analog Ground
AGND
15, 19
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1.11 Package Pin Assignments
VBH48A Pin # Pin Name
VBH48A Pin # Pin Name
41
42
43
44
45
46
47
48
RX_ER/MDIX_EN
COL/PHYAD0
RXD_0/PHYAD1
RXD_1/PHYAD2
RXD_2/PHYAD3
RXD_3/PHYAD4
IOGND
1
TX_CLK
TX_EN
2
3
TXD_0
4
TXD_1
5
TXD_2
6
TXD_3/SNI_MODE
PWR_DOWN/INT
TCK
IOVDD33
7
8
9
TDO
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
39
40
TMS
TRST#
TDI
RD -
RD +
AGND
TD -
TD +
PFBIN1
AGND
RESERVED
RESERVED
AVDD33
PFBOUT
RBIAS
25MHz_OUT
LED_ACT/COL/AN_EN
LED_SPEED/AN1
LED_LINK/AN0
RESET_N
MDIO
MDC
IOVDD33
X2
X1
IOGND
DGND
PFBIN2
RX_CLK
RX_DV/MII_MODE
CRS/CRS_DV/LED_CFG
15
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2.0 Configuration
This section includes information on the various configura-
tion options available with the DP83848I. The configuration
options described below include:
Table 1. Auto-Negotiation Modes
AN_EN AN1
AN0
Forced Mode
0
0
0
0
0
0
1
1
0
1
10BASE-T, Half-Duplex
10BASE-T, Full-Duplex
100BASE-TX, Half-Duplex
100BASE-TX, Full-Duplex
Advertised Mode
— Auto-Negotiation
— PHY Address and LEDs
— Half Duplex vs. Full Duplex
— Isolate mode
0
1
— Loopback mode
— BIST
AN_EN AN1
AN0
0
1
1
1
0
0
1
10BASE-T, Half/Full-Duplex
100BASE-TX, Half/Full-Duplex
10BASE-T Half-Duplex
1
2.1 Auto-Negotiation
0
The Auto-Negotiation function provides a mechanism for
exchanging configuration information between two ends of
a link segment and automatically selecting the highest per-
formance mode of operation supported by both devices.
Fast Link Pulse (FLP) Bursts provide the signalling used to
communicate Auto-Negotiation abilities between two
devices at each end of a link segment. For further detail
regarding Auto-Negotiation, refer to Clause 28 of the IEEE
802.3u specification. The DP83848I supports four different
Ethernet protocols (10 Mb/s Half Duplex, 10 Mb/s Full
Duplex, 100 Mb/s Half Duplex, and 100 Mb/s Full Duplex),
so the inclusion of Auto-Negotiation ensures that the high-
est performance protocol will be selected based on the
advertised ability of the Link Partner. The Auto-Negotiation
function within the DP83848I can be controlled either by
internal register access or by the use of the AN_EN, AN1
and AN0 pins.
100BASE-TX, Half-Duplex
10BASE-T, Half/Full-Duplex
100BASE-TX, Half/Full-Duplex
1
1
1
2.1.2 Auto-Negotiation Register Control
When Auto-Negotiation is enabled, the DP83848I transmits
the abilities programmed into the Auto-Negotiation Adver-
tisement register (ANAR) at address 04h via FLP Bursts.
Any combination of 10 Mb/s, 100 Mb/s, Half-Duplex, and
Full Duplex modes may be selected.
Auto-Negotiation Priority Resolution:
— (1) 100BASE-TX Full Duplex (Highest Priority)
— (2) 100BASE-TX Half Duplex
— (3) 10BASE-T Full Duplex
2.1.1 Auto-Negotiation Pin Control
— (4) 10BASE-T Half Duplex (Lowest Priority)
The Basic Mode Control Register (BMCR) at address 00h
provides control for enabling, disabling, and restarting the
Auto-Negotiation process. When Auto-Negotiation is dis-
abled, the Speed Selection bit in the BMCR controls
switching between 10 Mb/s or 100 Mb/s operation, and the
Duplex Mode bit controls switching between full duplex
operation and half duplex operation. The Speed Selection
and Duplex Mode bits have no effect on the mode of oper-
The state of AN_EN, AN0 and AN1 determines whether the
DP83848I is forced into a specific mode or Auto-Negotia-
tion will advertise a specific ability (or set of abilities) as
given in Table 1. These pins allow configuration options to
be selected without requiring internal register access.
The state of AN_EN, AN0 and AN1, upon power-up/reset,
determines the state of bits [8:5] of the ANAR register.
The Auto-Negotiation function selected at power-up or ation when the Auto-Negotiation Enable bit is set.
reset can be changed at any time by writing to the Basic
Mode Control Register (BMCR) at address 0x00h.
The Link Speed can be examined through the PHY Status
Register (PHYSTS) at address 10h after a Link is
achieved.
The Basic Mode Status Register (BMSR) indicates the set
of available abilities for technology types, Auto-Negotiation
ability, and Extended Register Capability. These bits are
permanently set to indicate the full functionality of the
DP83848I (only the 100BASE-T4 bit is not set since the
DP83848I does not support that function).
The BMSR also provides status on:
— Whether or not Auto-Negotiation is complete
— Whether or not the Link Partner is advertising that a re-
mote fault has occurred
— Whether or not valid link has been established
— Support for Management Frame Preamble suppression
The Auto-Negotiation Advertisement Register (ANAR)
indicates the Auto-Negotiation abilities to be advertised by
the DP83848I. All available abilities are transmitted by
default, but any ability can be suppressed by writing to the
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ANAR. Updating the ANAR to suppress an ability is one 2.1.4 Auto-Negotiation Restart
way for a management agent to change (restrict) the tech-
nology that is used.
Once Auto-Negotiation has completed, it may be restarted
at any time by setting bit 9 (Restart Auto-Negotiation) of the
BMCR to one. If the mode configured by a successful Auto-
Negotiation loses a valid link, then the Auto-Negotiation
process will resume and attempt to determine the configu-
ration for the link. This function ensures that a valid config-
uration is maintained if the cable becomes disconnected.
The Auto-Negotiation Link Partner Ability Register
(ANLPAR) at address 05h is used to receive the base link
code word as well as all next page code words during the
negotiation. Furthermore, the ANLPAR will be updated to
either 0081h or 0021h for parallel detection to either 100
Mb/s or 10 Mb/s respectively.
A renegotiation request from any entity, such as a manage-
ment agent, will cause the DP83848I to halt any transmit
data and link pulse activity until the break_link_timer
expires (~1500 ms). Consequently, the Link Partner will go
into link fail and normal Auto-Negotiation resumes. The
DP83848I will resume Auto-Negotiation after the
break_link_timer has expired by issuing FLP (Fast Link
Pulse) bursts.
The Auto-Negotiation Expansion Register (ANER) indi-
cates additional Auto-Negotiation status. The ANER pro-
vides status on:
— Whether or not a Parallel Detect Fault has occurred
— Whether or not the Link Partner supports the Next Page
function
— Whether or not the DP83848I supports the Next Page
function
2.1.5 Enabling Auto-Negotiation via Software
— Whether or not the current page being exchanged by
Auto-Negotiation has been received
It is important to note that if the DP83848I has been initial-
ized upon power-up as a non-auto-negotiating device
(forced technology), and it is then required that Auto-Nego-
tiation or re-Auto-Negotiation be initiated via software,
bit 12 (Auto-Negotiation Enable) of the Basic Mode Control
Register (BMCR) must first be cleared and then set for any
Auto-Negotiation function to take effect.
— Whether or not the Link Partner supports Auto-Negotia-
tion
2.1.3 Auto-Negotiation Parallel Detection
The DP83848I supports the Parallel Detection function as
defined in the IEEE 802.3u specification. Parallel Detection
requires both the 10 Mb/s and 100 Mb/s receivers to moni-
tor the receive signal and report link status to the Auto-
Negotiation function. Auto-Negotiation uses this informa-
tion to configure the correct technology in the event that the
Link Partner does not support Auto-Negotiation but is
transmitting link signals that the 100BASE-TX or 10BASE-
T PMAs recognize as valid link signals.
2.1.6 Auto-Negotiation Complete Time
Parallel detection and Auto-Negotiation take approximately
2-3 seconds to complete. In addition, Auto-Negotiation with
next page should take approximately 2-3 seconds to com-
plete, depending on the number of next pages sent.
Refer to Clause 28 of the IEEE 802.3u standard for a full
description of the individual timers related to Auto-Negotia-
tion.
If the DP83848I completes Auto-Negotiation as a result of
Parallel Detection, bits 5 and 7 within the ANLPAR register
will be set to reflect the mode of operation present in the
Link Partner. Note that bits 4:0 of the ANLPAR will also be
set to 00001 based on a successful parallel detection to
indicate a valid 802.3 selector field. Software may deter-
mine that negotiation completed via Parallel Detection by
reading a zero in the Link Partner Auto-Negotiation Able bit
once the Auto-Negotiation Complete bit is set. If configured
for parallel detect mode and any condition other than a sin-
gle good link occurs then the parallel detect fault bit will be
set.
2.2 Auto-MDIX
When enabled, this function utilizes Auto-Negotiation to
determine the proper configuration for transmission and
reception of data and subsequently selects the appropriate
MDI pair for MDI/MDIX operation. The function uses a ran-
dom seed to control switching of the crossover circuitry.
This implementation complies with the corresponding IEEE
802.3 Auto-Negotiation and Crossover Specifications.
Auto-MDIX is enabled by default and can be configured via
strap or via PHYCR (0x19h) register, bits [15:14].
Neither Auto-Negotiation nor Auto-MDIX is required to be
enabled in forcing crossover of the MDI pairs. Forced
crossover can be achieved through the FORCE_MDIX bit,
bit 14 of PHYCR (0x19h) register.
Note: Auto-MDIX will not work in a forced mode of opera-
tion.
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Since the PHYAD[0] pin has weak internal pull-up resistor
and PHYAD[4:1] pins have weak internal pull-down resis-
tors, the default setting for the PHY address is 00001
(01h).
2.3 PHY Address
The 5 PHY address inputs pins are shared with the
RXD[3:0] pins and COL pin as shown below.
Refer to Figure 2 for an example of a PHYAD connection to
external components. In this example, the PHYAD strap-
ping results in address 00011 (03h).
Table 2. PHY Address Mapping
Pin #
42
PHYAD Function
PHYAD0
RXD Function
COL
43
PHYAD1
RXD_0
2.3.1 MII Isolate Mode
44
PHYAD2
RXD_1
The DP83848I can be put into MII Isolate mode by writing
to bit 10 of the BMCR register or by strapping in Physical
Address 0. It should be noted that selecting Physical
Address 0 via an MDIO write to PHYCR will not put the
device in the MII isolate mode.
45
PHYAD3
RXD_2
46
PHYAD4
RXD_3
The DP83848I can be set to respond to any of 32 possible
PHY addresses via strap pins. The information is latched
into the PHYCR register (address 19h, bits [4:0]) at device
power-up and hardware reset. The PHY Address pins are
shared with the RXD and COL pins. Each DP83848I or port
sharing an MDIO bus in a system must have a unique
physical address.
When in the MII isolate mode, the DP83848I does not
respond to packet data present at TXD[3:0], TX_EN inputs
and presents a high impedance on the TX_CLK, RX_CLK,
RX_DV, RX_ER, RXD[3:0], COL, and CRS outputs. When
in Isolate mode, the DP83848I will continue to respond to
all management transactions.
While in Isolate mode, the PMD output pair will not transmit
packet data but will continue to source 100BASE-TX
scrambled idles or 10BASE-T normal link pulses.
The DP83848I supports PHY Address strapping values 0
(<00000>) through 31 (<11111>). Strapping PHY Address
0 puts the part into Isolate Mode. It should also be noted
that selecting PHY Address 0 via an MDIO write to PHYCR
will not put the device in Isolate Mode. See Section 2.3.1for
more information.
The DP83848I can Auto-Negotiate or parallel detect to a
specific technology depending on the receive signal at the
PMD input pair. A valid link can be established for the
receiver even when the DP83848I is in Isolate mode.
For further detail relating to the latch-in timing requirements
of the PHY Address pins, as well as the other hardware
configuration pins, refer to the Reset summary in
Section 6.0.
PHYAD3 = 0 PHYAD2 = 0 PHYAD1 = 1 PHYAD0 = 1
PHYAD4= 0
VCC
Figure 2. PHYAD Strapping Example
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2.4 LED Interface
multiplexed among the LEDs. The PHY Control Register
(PHYCR) for the LEDs can also be selected through
address 19h, bits [6:5].
The DP83848I supports three configurable Light Emitting
Diode (LED) pins. The device supports three LED configu-
rations: Link, Speed, Activity and Collision. Function are
See Table 3 for LED Mode selection.
Table 3. LED Mode Select
Mode
LED_CFG[1]
(bit 6)
LED_CFG[0]
(bit 5)
LED_LINK
LED_SPEED
LED_ACT/COL
or (pin40)
1
2
3
don’t care
1
ON for Good Link
OFF for No Link
ON for Good Link
BLINK for Activity
ON for Good Link
BLINK for Activity
ON in 100 Mb/s
OFF in 10 Mb/s
ON in 100 Mb/s
OFF in 10 Mb/s
ON in 100 Mb/s
OFF in 10 Mb/s
ON for Activity
OFF for No Activity
ON for Collision
0
1
0
0
OFF for No Collision
ON for Full Duplex
OFF for Half Duplex
The LED_LINK pin in Mode 1 indicates the link status of Specifically, when the LED outputs are used to drive LEDs
the port. In 100BASE-T mode, link is established as a directly, the active state of each output driver is dependent
result of input receive amplitude compliant with the TP- on the logic level sampled by the corresponding AN input
PMD specifications which will result in internal generation upon power-up/reset. For example, if a given AN input is
of signal detect. A 10 Mb/s Link is established as a result of resistively pulled low then the corresponding output will be
the reception of at least seven consecutive normal Link configured as an active high driver. Conversely, if a given
Pulses or the reception of a valid 10BASE-T packet. This AN input is resistively pulled high, then the corresponding
will cause the assertion of LED_LINK. LED_LINK will deas- output will be configured as an active low driver.
sert in accordance with the Link Loss Timer as specified in
the IEEE 802.3 specification.
Refer to Figure 3 for an example of AN connections to
external components. In this example, the AN strapping
The LED_LINK pin in Mode 1 will be OFF when no LINK is results in Auto-Negotiation with 10/100 Half/Full-Duplex
present.
advertised.
The LED_LINK pin in Mode 2 and Mode 3 will be ON to The adaptive nature of the LED outputs helps to simplify
indicate Link is good and BLINK to indicate activity is potential implementation issues of these dual purpose pins.
present on either transmit or receive activity.
The LED_SPEED pin indicates 10 or 100 Mb/s data rate of
the port. The standard CMOS driver goes high when oper-
ating in 100 Mb/s operation. The functionality of this LED is
independent of mode selected.
The LED_ACT/COL pin in Mode 1 indicates the presence
of either transmit or receive activity. The LED will be ON for
Activity and OFF for No Activity. In Mode 2, this pin indi-
cates the Collision status of the port. The LED will be ON
for Collision and OFF for No Collision.
AN_EN = 1 AN1 = 1
AN0 = 1
The LED_ACT/COL pin in Mode 3 indicates the presence
of Duplex status for 10 Mb/s or 100 Mb/s operation. The
LED will be ON for Full Duplex and OFF for Half Duplex.
In 10 Mb/s half duplex mode, the collision LED is based on
the COL signal.
Since these LED pins are also used as strap options, the
polarity of the LED is dependent on whether the pin is
pulled up or down.
VCC
2.4.1 LEDs
Since the Auto-Negotiation (AN) strap options share the
LED output pins, the external components required for
strapping and LED usage must be considered in order to
avoid contention.
Figure 3. AN Strapping and LED Loading Example
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2.4.2 LED Direct Control
2.6 Internal Loopback
The DP83848I provides another option to directly control
any or all LED outputs through the LED Direct Control Reg-
ister (LEDCR), address 18h. The register does not provide
read access to LEDs.
The DP83848I includes a Loopback Test mode for facilitat-
ing system diagnostics. The Loopback mode is selected
through bit 14 (Loopback) of the Basic Mode Control Reg-
ister (BMCR). Writing 1 to this bit enables MII transmit data
to be routed to the MII receive outputs. Loopback status
may be checked in bit 3 of the PHY Status Register
(PHYSTS). While in Loopback mode the data will not be
transmitted onto the media. To ensure that the desired
operating mode is maintained, Auto-Negotiation should be
disabled before selecting the Loopback mode.
2.5 Half Duplex vs. Full Duplex
The DP83848I supports both half and full duplex operation
at both 10 Mb/s and 100 Mb/s speeds.
Half-duplex relies on the CSMA/CD protocol to handle colli-
sions and network access. In Half-Duplex mode, CRS
responds to both transmit and receive activity in order to
maintain compliance with the IEEE 802.3 specification.
2.7 BIST
The DP83848I incorporates an internal Built-in Self Test
(BIST) circuit to accommodate in-circuit testing or diagnos-
tics. The BIST circuit can be utilized to test the integrity of
the transmit and receive data paths. BIST testing can be
performed with the part in the internal loopback mode or
externally looped back using a loopback cable fixture.
Since the DP83848I is designed to support simultaneous
transmit and receive activity it is capable of supporting full-
duplex switched applications with a throughput of up to 200
Mb/s per port when operating in 100BASE-TX mode.
Because the CSMA/CD protocol does not apply to full-
duplex operation, the DP83848I disables its own internal
collision sensing and reporting functions and modifies the
behavior of Carrier Sense (CRS) such that it indicates only
receive activity. This allows a full-duplex capable MAC to
operate properly.
The BIST is implemented with independent transmit and
receive paths, with the transmit block generating a continu-
ous stream of a pseudo random sequence. The user can
select a 9 bit or 15 bit pseudo random sequence from the
PSR_15 bit in the PHY Control Register (PHYCR). The
received data is compared to the generated pseudo-ran-
dom data by the BIST Linear Feedback Shift Register
(LFSR) to determine the BIST pass/fail status.
All modes of operation (100BASE-TX and 10BASE-T) can
run either half-duplex or full-duplex. Additionally, other than
CRS and Collision reporting, all remaining MII signaling
remains the same regardless of the selected duplex mode.
The pass/fail status of the BIST is stored in the BIST status
bit in the PHYCR register. The status bit defaults to 0 (BIST
fail) and will transition on a successful comparison. If an
error (mis-compare) occurs, the status bit is latched and is
cleared upon a subsequent write to the Start/Stop bit.
It is important to understand that while Auto-Negotiation
with the use of Fast Link Pulse code words can interpret
and configure to full-duplex operation, parallel detection
can not recognize the difference between full and half-
duplex from a fixed 10 Mb/s or 100 Mb/s link partner over
twisted pair. As specified in the 802.3u specification, if a
far-end link partner is configured to a forced full duplex
100BASE-TX ability, the parallel detection state machine in
the partner would be unable to detect the full duplex capa-
bility of the far-end link partner. This link segment would
negotiate to a half duplex 100BASE-TX configuration
(same scenario for 10 Mb/s).
For transmit VOD testing, the Packet BIST Continuous
Mode can be used to allow continuous data transmission,
setting BIST_CONT_MODE, bit 5, of CDCTRL1 (0x1Bh).
The number of BIST errors can be monitored through the
BIST Error Count in the CDCTRL1 (0x1Bh), bits [15:8].
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If the DP83848I is transmitting in 10 Mb/s mode when a
collision is detected, the collision is not reported until seven
bits have been received while in the collision state. This
prevents a collision being reported incorrectly due to noise
on the network. The COL signal remains set for the dura-
tion of the collision.
3.0 Functional Description
The DP83848I supports several modes of operation using
the MII interface pins. The options are defined in the follow-
ing sections and include:
— MII Mode
If a collision occurs during a receive operation, it is immedi-
ately reported by the COL signal.
— RMII Mode
— 10 Mb Serial Network Interface (SNI)
When heartbeat is enabled (only applicable to 10 Mb/s
operation), approximately 1µs after the transmission of
each packet, a Signal Quality Error (SQE) signal of approx-
imately 10 bit times is generated (internally) to indicate
successful transmission. SQE is reported as a pulse on the
COL signal of the MII.
The modes of operation can be selected by strap options
or register control. For RMII mode, it is required to use the
strap option, since it requires a 50 MHz clock instead of the
normal 25 MHz.
In each of these modes, the IEEE 802.3 serial manage-
ment interface is operational for device configuration and
status. The serial management interface of the MII allows
for the configuration and control of multiple PHY devices,
gathering of status, error information, and the determina-
tion of the type and capabilities of the attached PHY(s).
3.1.3 Carrier Sense
Carrier Sense (CRS) is asserted due to receive activity,
once valid data is detected via the squelch function during
10 Mb/s operation. During 100 Mb/s operation CRS is
asserted when a valid link (SD) and two non-contiguous
zeros are detected on the line.
3.1 MII Interface
The DP83848I incorporates the Media Independent Inter-
face (MII) as specified in Clause 22 of the IEEE 802.3u
standard. This interface may be used to connect PHY
devices to a MAC in 10/100 Mb/s systems. This section
describes the nibble wide MII data interface.
For 10 or 100 Mb/s Half Duplex operation, CRS is asserted
during either packet transmission or reception.
For 10 or 100 Mb/s Full Duplex operation, CRS is asserted
only due to receive activity.
The nibble wide MII data interface consists of a receive bus
and a transmit bus each with control signals to facilitate
data transfer between the PHY and the upper layer (MAC).
CRS is deasserted following an end of packet.
3.2 Reduced MII Interface
The DP83848I incorporates the Reduced Media Indepen-
dent Interface (RMII) as specified in the RMII specification
(rev1.2) from the RMII Consortium. This interface may be
used to connect PHY devices to a MAC in 10/100 Mb/s
systems using a reduced number of pins. In this mode,
data is transferred 2-bits at a time using the 50 MHz
RMII_REF clock for both transmit and receive. The follow-
ing pins are used in RMII mode:
3.1.1 Nibble-wide MII Data Interface
Clause 22 of the IEEE 802.3u specification defines the
Media Independent Interface. This interface includes a
dedicated receive bus and a dedicated transmit bus. These
two data buses, along with various control and status sig-
nals, allow for the simultaneous exchange of data between
the DP83848I and the upper layer agent (MAC).
The receive interface consists of a nibble wide data bus
RXD[3:0], a receive error signal RX_ER, a receive data
valid flag RX_DV, and a receive clock RX_CLK for syn-
chronous transfer of the data. The receive clock operates
— TX_EN
— TXD[1:0]
— RX_ER (optional for Mac)
at either 2.5 MHz to support 10 Mb/s operation modes or at — CRS_DV
25 MHz to support 100 Mb/s operational modes.
— RXD[1:0]
The transmit interface consists of a nibble wide data bus
TXD[3:0], a transmit enable control signal TX_EN, and a
transmit clock TX_CLK which runs at either 2.5 MHz or 25
MHz.
— X1 (RMII Reference clock is 50 MHz)
In addition, the RMII mode supplies an RX_DV signal
which allows for a simpler method of recovering receive
data without having to separate RX_DV from the CRS_DV
indication. This is especially useful for systems which do
not require CRS, such as systems that only support full-
duplex operation. This signal is also useful for diagnostic
testing where it may be desirable to loop Receive RMII
data directly to the transmitter.
Additionally, the MII includes the carrier sense signal CRS,
as well as a collision detect signal COL. The CRS signal
asserts to indicate the reception of data from the network
or as a function of transmit data in Half Duplex mode. The
COL signal asserts as an indication of a collision which can
occur during half-duplex operation when both a transmit
and receive operation occur simultaneously.
Since the reference clock operates at 10 times the data
rate for 10 Mb/s operation, transmit data is sampled every
10 clocks. Likewise, receive data will be generated every
10th clock so that an attached device can sample the data
every 10 clocks.
3.1.2 Collision Detect
RMII mode requires a 50 MHz oscillator be connected to
the device X1 pin. A 50 MHz crystal is not supported.
For Half Duplex, a 10BASE-T or 100BASE-TX collision is
detected when the receive and transmit channels are
active simultaneously. Collisions are reported by the COL
signal on the MII.
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To tolerate potential frequency differences between the 50 The elasticity buffer will force Frame Check Sequence
MHz reference clock and the recovered receive clock, the errors for packets which overrun or underrun the FIFO.
receive RMII function includes a programmable elasticity Underrun and Overrun conditions can be reported in the
buffer. The elasticity buffer is programmable to minimize RMII and Bypass Register (RBR). The following table indi-
propagation delay based on expected packet size and cates how to program the elasticity buffer fifo (in 4-bit incre-
clock accuracy. This allows for supporting a range of ments) based on expected max packet size and clock
packet sizes including jumbo frames.
accuracy. It assumes both clocks (RMII Reference clock
and far-end Transmitter clock) have the same accuracy.
Table 4. Supported packet sizes at +/-50ppm +/-100ppm for each clock
Start Threshold
RBR[1:0]
Latency Tolerance
Recommended Packet Size Recommended Packet Size
at +/- 50ppm
2400 bytes
7200 bytes
12000 bytes
16800 bytes
at +/- 100ppm
1200 bytes
3600 bytes
6000 bytes
8400 bytes
1 (4-bits)
2 (8-bits)
3 (12-bits)
0 (16-bits)
2 bits
6 bits
10 bits
14 bits
The MDIO pin requires a pull-up resistor (1.5 kΩ) which,
during IDLE and turnaround, will pull MDIO high. In order to
initialize the MDIO interface, the station management entity
sends a sequence of 32 contiguous logic ones on MDIO to
provide the DP83848I with a sequence that can be used to
establish synchronization. This preamble may be gener-
ated either by driving MDIO high for 32 consecutive MDC
clock cycles, or by simply allowing the MDIO pull-up resis-
tor to pull the MDIO pin high during which time 32 MDC
clock cycles are provided. In addition 32 MDC clock cycles
should be used to re-sync the device if an invalid start,
opcode, or turnaround bit is detected.
3.3 10 Mb Serial Network Interface (SNI)
The DP83848I incorporates a 10 Mb Serial Network Inter-
face (SNI) which allows a simple serial data interface for 10
Mb only devices. This is also referred to as a 7-wire inter-
face. While there is no defined standard for this interface, it
is based on early 10 Mb physical layer devices. Data is
clocked serially at 10 MHz using separate transmit and
receive paths. The following pins are used in SNI mode:
— TX_CLK
— TX_EN
— TXD[0]
— RX_CLK
— RXD[0]
— CRS
The DP83848I waits until it has received this preamble
sequence before responding to any other transaction.
Once the DP83848I serial management port has been ini-
tialized no further preamble sequencing is required until
after a power-on/reset, invalid Start, invalid Opcode, or
invalid turnaround bit has occurred.
— COL
The Start code is indicated by a <01> pattern. This assures
the MDIO line transitions from the default idle line state.
3.4 802.3u MII Serial Management Interface
Turnaround is defined as an idle bit time inserted between
the Register Address field and the Data field. To avoid con-
tention during a read transaction, no device shall actively
drive the MDIO signal during the first bit of Turnaround.
The addressed DP83848I drives the MDIO with a zero for
the second bit of turnaround and follows this with the
required data. Figure 4 shows the timing relationship
between MDC and the MDIO as driven/received by the Sta-
tion (STA) and the DP83848I (PHY) for a typical register
read access.
3.4.1 Serial Management Register Access
The serial management MII specification defines a set of
thirty-two 16-bit status and control registers that are acces-
sible through the management interface pins MDC and
MDIO. The DP83848I implements all the required MII reg-
isters as well as several optional registers. These registers
are fully described in Section 7.0. A description of the serial
management access protocol follows.
For write transactions, the station management entity
writes data to the addressed DP83848I thus eliminating the
requirement for MDIO Turnaround. The Turnaround time is
filled by the management entity by inserting <10>. Figure 5
shows the timing relationship for a typical MII register write
access.
3.4.2 Serial Management Access Protocol
The serial control interface consists of two pins, Manage-
ment Data Clock (MDC) and Management Data Input/Out-
put (MDIO). MDC has a maximum clock rate of 25 MHz
and no minimum rate. The MDIO line is bi-directional and
may be shared by up to 32 devices. The MDIO frame for-
mat is shown below in Table 5.
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Table 5. Typical MDIO Frame Format
MII Management
Serial Protocol
<idle><start><op code><device addr><reg addr><turnaround><data><idle>
Read Operation
Write Operation
<idle><01><10><AAAAA><RRRRR><Z0><xxxx xxxx xxxx xxxx><idle>
<idle><01><01><AAAAA><RRRRR><10><xxxx xxxx xxxx xxxx><idle>
MDC
Z
MDIO
(STA)
Z
Z
Z
MDIO
(PHY)
Z
Z
Z
0 1 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0
Opcode
(Read)
Register Address
(00h = BMCR)
PHY Address
Register Data
Idle
TA
Idle
Start
(PHYAD = 0Ch)
Figure 4. Typical MDC/MDIO Read Operation
MDC
Z
Z
MDIO
(STA)
Z
Z
0 1 0 1 0 1 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
PHY Address
Register Address
(00h = BMCR)
Opcode
(Write)
Register Data
Idle
Idle
Start
TA
(PHYAD = 0Ch)
Figure 5. Typical MDC/MDIO Write Operation
3.4.3 Serial Management Preamble Suppression
requirement is generally met by the mandatory pull-up
resistor on MDIO in conjunction with a continuous MDC, or
the management access made to determine whether Pre-
amble Suppression is supported.
The DP83848I supports a Preamble Suppression mode as
indicated by a one in bit 6 of the Basic Mode Status Regis-
ter (BMSR, address 01h.) If the station management entity
(i.e. MAC or other management controller) determines that
all PHYs in the system support Preamble Suppression by
returning a one in this bit, then the station management
entity need not generate preamble for each management
transaction.
While the DP83848I requires an initial preamble sequence
of 32 bits for management initialization, it does not require
a full 32-bit sequence between each subsequent transac-
tion. A minimum of one idle bit between management
transactions is required as specified in the IEEE 802.3u
specification.
The DP83848I requires a single initialization sequence of
32 bits of preamble following hardware/software reset. This
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The block diagram in Figure 6. provides an overview of
each functional block within the 100BASE-TX transmit sec-
tion.
4.0 Architecture
This section describes the operations within each trans-
ceiver module, 100BASE-TX and 10BASE-T. Each opera-
tion consists of several functional blocks and described in
the following:
The Transmitter section consists of the following functional
blocks:
— Code-group Encoder and Injection block
— Scrambler block (bypass option)
— 100BASE-TX Transmitter
— 100BASE-TX Receiver
— NRZ to NRZI encoder block
— 10BASE-T Transceiver Module
— Binary to MLT-3 converter / Common Driver
The bypass option for the functional blocks within the
100BASE-TX transmitter provides flexibility for applications
where data conversion is not always required. The
DP83848I implements the 100BASE-TX transmit state
machine diagram as specified in the IEEE 802.3u Stan-
dard, Clause 24.
4.1 100BASE-TX TRANSMITTER
The 100BASE-TX transmitter consists of several functional
blocks which convert synchronous 4-bit nibble data, as pro-
vided by the MII, to a scrambled MLT-3 125 Mb/s serial
data stream. Because the 100BASE-TX TP-PMD is inte-
grated, the differential output pins, PMD Output Pair, can
be directly routed to the magnetics.
TX_CLK
TXD[3:0] /
TX_EN
DIVIDE
BY 5
4B5B CODE-
GROUP
ENCODER &
5B PARALLEL
TO SERIAL
125MHZ CLOCK
SCRAMBLER
MUX
BP_SCR
MLT[1:0]
100BASE-TX
LOOPBACK
NRZ TO NRZI
ENCODER
BINARY
TO MLT-3 /
COMMON
DRIVER
PMD OUTPUT PAIR
Figure 6. 100BASE-TX Transmit Block Diagram
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Table 5. 4B5B CCode-group Encoding and Injection
6.
DATA CODES
0
11110
01001
10100
10101
01010
01011
01110
01111
10010
10011
10110
10111
11010
11011
11100
11101
0000
1
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
2
3
4
5
6
7
8
9
A
B
C
D
E
F
IDLE AND CONTROL CODES
H
00100
11111
11000
10001
01101
00111
HALT code-group - Error code
I
Inter-Packet IDLE - 0000 (Note 1)
First Start of Packet - 0101 (Note 1)
Second Start of Packet - 0101 (Note 1)
First End of Packet - 0000 (Note 1)
Second End of Packet - 0000 (Note 1)
J
K
T
R
INVALID CODES
V
V
V
V
V
V
V
V
00000
00001
00010
00011
00101
00110
01000
01100
Note: Control code-groups I, J, K, T and R in data fields will be mapped as invalid codes, together with RX_ER as-
serted.
The code-group encoder converts 4-bit (4B) nibble data code-group pair (01101 00111) indicating the end of the
generated by the MAC into 5-bit (5B) code-groups for frame.
transmission. This conversion is required to allow control
After the T/R code-group pair, the code-group encoder
data to be combined with packet data code-groups. Refer
continuously injects IDLEs into the transmit data stream
to Table 5 for 4B to 5B code-group mapping details.
until the next transmit packet is detected (reassertion of
The code-group encoder substitutes the first 8-bits of the Transmit Enable).
MAC preamble with a J/K code-group pair (11000 10001)
upon transmission. The code-group encoder continues to
replace subsequent 4B preamble and data nibbles with
corresponding 5B code-groups. At the end of the transmit
4.1.1 Scrambler
The scrambler is required to control the radiated emissions
at the media connector and on the twisted pair cable (for
packet, upon the deassertion of Transmit Enable signal
from the MAC, the code-group encoder injects the T/R
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100BASE-TX applications). By scrambling the data, the
total energy launched onto the cable is randomly distrib-
uted over a wide frequency range. Without the scrambler,
energy levels at the PMD and on the cable could peak
beyond FCC limitations at frequencies related to repeating
5B sequences (i.e., continuous transmission of IDLEs).
4.2 100BASE-TX RECEIVER
The 100BASE-TX receiver consists of several functional
blocks which convert the scrambled MLT-3 125 Mb/s serial
data stream to synchronous 4-bit nibble data that is pro-
vided to the MII. Because the 100BASE-TX TP-PMD is
integrated, the differential input pins, RD±, can be directly
routed from the AC coupling magnetics.
The scrambler is configured as a closed loop linear feed-
back shift register (LFSR) with an 11-bit polynomial. The
output of the closed loop LFSR is X-ORd with the serial
NRZ data from the code-group encoder. The result is a
scrambled data stream with sufficient randomization to
See Figure 7 for a block diagram of the 100BASE-TX
receive function. This provides an overview of each func-
tional block within the 100BASE-TX receive section.
decrease radiated emissions at certain frequencies by as The Receive section consists of the following functional
much as 20 dB. The DP83848I uses the PHY_ID (pins blocks:
PHYAD [4:0]) to set a unique seed value.
— Analog Front End
— Digital Signal Processor
— Signal Detect
4.1.2 NRZ to NRZI Encoder
— MLT-3 to Binary Decoder
After the transmit data stream has been serialized and
scrambled, the data must be NRZI encoded in order to
— NRZI to NRZ Decoder
— Serial to Parallel
— Descrambler
comply with the TP-PMD standard for 100BASE-TX trans-
mission over Category-5 Unshielded twisted pair cable.
— Code Group Alignment
— 4B/5B Decoder
4.1.3 Binary to MLT-3 Convertor
— Link Integrity Monitor
— Bad SSD Detection
The Binary to MLT-3 conversion is accomplished by con-
verting the serial binary data stream output from the NRZI
encoder into two binary data streams with alternately
phased logic one events. These two binary streams are
then fed to the twisted pair output driver which converts the
voltage to current and alternately drives either side of the
transmit transformer primary winding, resulting in a MLT-3
signal.
4.2.1 Analog Front End
In addition to the Digital Equalization and Gain Control, the
DP83848I includes Analog Equalization and Gain Control
in the Analog Front End. The Analog Equalization reduces
the amount of Digital Equalization required in the DSP.
The 100BASE-TX MLT-3 signal sourced by the PMD Out-
put Pair common driver is slew rate controlled. This should
be considered when selecting AC coupling magnetics to
ensure TP-PMD Standard compliant transition times (3 ns
< Tr < 5 ns).
4.2.2 Digital Signal Processor
The Digital Signal Processor includes Adaptive Equaliza-
tion with Gain Control and Base Line Wander Compensa-
tion.
The 100BASE-TX transmit TP-PMD function within the
DP83848I is capable of sourcing only MLT-3 encoded data.
Binary output from the PMD Output Pair is not possible in
100 Mb/s mode.
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RX_DV/CRS
RX_CLK
RXD[3:0] / RX_ER
4B/5B DECODER
SERIAL TO
PARALLEL
CODE GROUP
ALIGNMENT
LINK
INTEGRITY
MONITOR
RX_DATA
VALID SSD
DETECT
DESCRAMBLER
NRZI TO NRZ
DECODER
MLT-3 TO BINARY
DECODER
SIGNAL
DETECT
DIGITAL
SIGNAL
PROCESSOR
ANALOG
FRONT
END
RD +/−
Figure 7. 100BASE-TX Receive Block Diagram
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4.2.2.1 Digital Adaptive Equalization and Gain Control tive to ensure proper conditioning of the received signal
independent of the cable length.
When transmitting data at high speeds over copper twisted
The DP83848I utilizes an extremely robust equalization
scheme referred as ‘Digital Adaptive Equalization.’
pair cable, frequency dependent attenuation becomes a
concern. In high-speed twisted pair signalling, the fre-
quency content of the transmitted signal can vary greatly
during normal operation based primarily on the random-
ness of the scrambled data stream. This variation in signal
attenuation caused by frequency variations must be com-
pensated to ensure the integrity of the transmission.
The Digital Equalizer removes ISI (inter symbol interfer-
ence) from the receive data stream by continuously adapt-
ing to provide a filter with the inverse frequency response
of the channel. Equalization is combined with an adaptive
gain control stage. This enables the receive 'eye pattern' to
be opened sufficiently to allow very reliable data recovery.
In order to ensure quality transmission when employing
MLT-3 encoding, the compensation must be able to adapt
to various cable lengths and cable types depending on the
installed environment. The selection of long cable lengths
for a given implementation, requires significant compensa-
tion which will over-compensate for shorter, less attenuat-
ing lengths. Conversely, the selection of short or
intermediate cable lengths requiring less compensation will
cause serious under-compensation for longer length
cables. The compensation or equalization must be adap-
The curves given in Figure 8 illustrate attenuation at certain
frequencies for given cable lengths. This is derived from
the worst case frequency vs. attenuation figures as speci-
fied in the EIA/TIA Bulletin TSB-36. These curves indicate
the significant variations in signal attenuation that must be
compensated for by the receive adaptive equalization cir-
cuit.
Figure 8. EIA/TIA Attenuation vs. Frequency for 0, 50,
100, 130 & 150 meters of CAT 5 cable
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4.2.2.2 Base Line Wander Compensation
Figure 9. 100BASE-TX BLW Event
The DP83848I is completely ANSI TP-PMD compliant and PMD Standard as well as the IEEE 802.3 100BASE-TX
includes Base Line Wander (BLW) compensation. The Standard for both voltage thresholds and timing parame-
BLW compensation block can successfully recover the TP- ters.
PMD defined “killer” pattern.
Note that the reception of normal 10BASE-T link pulses
BLW can generally be defined as the change in the aver- and fast link pulses per IEEE 802.3u Auto-Negotiation by
age DC content, relatively short period over time, of an AC the 100BASE-TX receiver do not cause the DP83848I to
coupled digital transmission over a given transmission assert signal detect.
medium. (i.e., copper wire).
BLW results from the interaction between the low fre-
quency components of a transmitted bit stream and the fre- 4.2.4 MLT-3 to NRZI Decoder
quency response of the AC coupling component(s) within
The DP83848I decodes the MLT-3 information from the
the transmission system. If the low frequency content of
Digital Adaptive Equalizer block to binary NRZI data.
the digital bit stream goes below the low frequency pole of
the AC coupling transformers then the droop characteris-
tics of the transformers will dominate resulting in potentially
serious BLW.
4.2.5 NRZI to NRZ
The digital oscilloscope plot provided in Figure 9 illustrates
the severity of the BLW event that can theoretically be gen-
erated during 100BASE-TX packet transmission. This
event consists of approximately 800 mV of DC offset for a
period of 120 µs. Left uncompensated, events such as this
can cause packet loss.
In a typical application, the NRZI to NRZ decoder is
required in order to present NRZ formatted data to the
descrambler.
4.2.6 Serial to Parallel
4.2.3 Signal Detect
The 100BASE-TX receiver includes a Serial to Parallel
converter which supplies 5-bit wide data symbols to the
PCS Rx state machine.
The signal detect function of the DP83848I is incorporated
to meet the specifications mandated by the ANSI FDDI TP-
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4.2.7 Descrambler
4.2.10 100BASE-TX Link Integrity Monitor
A serial descrambler is used to de-scramble the received The 100 Base TX Link monitor ensures that a valid and sta-
NRZ data. The descrambler has to generate an identical ble link is established before enabling both the Transmit
data scrambling sequence (N) in order to recover the origi- and Receive PCS layer.
nal unscrambled data (UD) from the scrambled data (SD)
as represented in the equations:
Signal detect must be valid for 395us to allow the link mon-
itor to enter the 'Link Up' state, and enable the transmit and
receive functions.
SD= (UD N)
UD= (SD N)
Synchronization of the descrambler to the original scram-
bling sequence (N) is achieved based on the knowledge
that the incoming scrambled data stream consists of
scrambled IDLE data. After the descrambler has recog-
nized 12 consecutive IDLE code-groups, where an
unscrambled IDLE code-group in 5B NRZ is equal to five
consecutive ones (11111), it will synchronize to the receive
data stream and generate unscrambled data in the form of
unaligned 5B code-groups.
4.2.11 Bad SSD Detection
A Bad Start of Stream Delimiter (Bad SSD) is any transition
from consecutive idle code-groups to non-idle code-groups
which is not prefixed by the code-group pair /J/K.
If this condition is detected, the DP83848I will assert
RX_ER and present RXD[3:0] = 1110 to the MII for the
cycles that correspond to received 5B code-groups until at
least two IDLE code groups are detected. In addition, the
False Carrier Sense Counter register (FCSCR) will be
incremented by one.
In order to maintain synchronization, the descrambler must
continuously monitor the validity of the unscrambled data
that it generates. To ensure this, a line state monitor and a
hold timer are used to constantly monitor the synchroniza-
tion status. Upon synchronization of the descrambler the
hold timer starts a 722 µs countdown. Upon detection of
sufficient IDLE code-groups (58 bit times) within the 722 µs
period, the hold timer will reset and begin a new count-
down. This monitoring operation will continue indefinitely
given a properly operating network connection with good
signal integrity. If the line state monitor does not recognize
sufficient unscrambled IDLE code-groups within the 722 µs
period, the entire descrambler will be forced out of the cur-
rent state of synchronization and reset in order to re-
acquire synchronization.
Once at least two IDLE code groups are detected, RX_ER
and CRS become de-asserted.
4.3 10BASE-T TRANSCEIVER MODULE
The 10BASE-T Transceiver Module is IEEE 802.3 compli-
ant. It includes the receiver, transmitter, collision, heart-
beat, loopback, jabber, and link integrity functions, as
defined in the standard. An external filter is not required on
the 10BASE-T interface since this is integrated inside the
DP83848I. This section focuses on the general 10BASE-T
system level operation.
4.2.8 Code-group Alignment
4.3.1 Operational Modes
The code-group alignment module operates on unaligned
5-bit data from the descrambler (or, if the descrambler is
bypassed, directly from the NRZI/NRZ decoder) and con-
verts it into 5B code-group data (5 bits). Code-group align-
ment occurs after the J/K code-group pair is detected.
Once the J/K code-group pair (11000 10001) is detected,
subsequent data is aligned on a fixed boundary.
The DP83848I has two basic 10BASE-T operational
modes:
— Half Duplex mode
— Full Duplex mode
Half Duplex Mode
In Half Duplex mode the DP83848I functions as a standard
IEEE 802.3 10BASE-T transceiver supporting the
CSMA/CD protocol.
4.2.9 4B/5B Decoder
The code-group decoder functions as a look up table that
translates incoming 5B code-groups into 4B nibbles. The
code-group decoder first detects the J/K code-group pair
preceded by IDLE code-groups and replaces the J/K with
MAC preamble. Specifically, the J/K 10-bit code-group pair
is replaced by the nibble pair (0101 0101). All subsequent
Full Duplex Mode
In Full Duplex mode the DP83848I is capable of simulta-
5B code-groups are converted to the corresponding 4B neously transmitting and receiving without asserting the
nibbles for the duration of the entire packet. This conver- collision signal. The DP83848I's 10 Mb/s ENDEC is
sion ceases upon the detection of the T/R code-group pair
denoting the End of Stream Delimiter (ESD) or with the
reception of a minimum of two IDLE code-groups.
designed to encode and decode simultaneously.
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4.3.2 Smart Squelch
within 150 ns. Finally the signal must again exceed the
original squelch level within a 150 ns to ensure that the
input waveform will not be rejected. This checking proce-
dure results in the loss of typically three preamble bits at
the beginning of each packet.
The smart squelch is responsible for determining when
valid data is present on the differential receive inputs. The
DP83848I implements an intelligent receive squelch to
ensure that impulse noise on the receive inputs will not be
mistaken for a valid signal. Smart squelch operation is
independent of the 10BASE-T operational mode.
Only after all these conditions have been satisfied will a
control signal be generated to indicate to the remainder of
the circuitry that valid data is present. At this time, the
smart squelch circuitry is reset.
The squelch circuitry employs a combination of amplitude
and timing measurements (as specified in the IEEE 802.3
10BSE-T standard) to determine the validity of data on the
twisted pair inputs (refer to Figure 10).
Valid data is considered to be present until the squelch
level has not been generated for a time longer than 150 ns,
indicating the End of Packet. Once good data has been
detected, the squelch levels are reduced to minimize the
effect of noise causing premature End of Packet detection.
The signal at the start of a packet is checked by the smart
squelch and any pulses not exceeding the squelch level
(either positive or negative, depending upon polarity) will
be rejected. Once this first squelch level is overcome cor-
rectly, the opposite squelch level must then be exceeded
<150 ns
>150 ns
<150 ns
V
SQ+
V
SQ+(reduced)
V
SQ-(reduced)
V
SQ-
end of packet
start of packet
Figure 10. 10BASE-T Twisted Pair Smart Squelch Operation
4.3.3 Collision Detection and SQE
4.3.4 Carrier Sense
When in Half Duplex, a 10BASE-T collision is detected Carrier Sense (CRS) may be asserted due to receive activ-
when the receive and transmit channels are active simulta- ity once valid data is detected via the squelch function.
neously. Collisions are reported by the COL signal on the
For 10 Mb/s Half Duplex operation, CRS is asserted during
MII. Collisions are also reported when a jabber condition is
either packet transmission or reception.
detected.
For 10 Mb/s Full Duplex operation, CRS is asserted only
The COL signal remains set for the duration of the collision.
during receive activity.
If the PHY is receiving when a collision is detected it is
CRS is deasserted following an end of packet.
reported immediately (through the COL pin).
When heartbeat is enabled, approximately 1 µs after the
transmission of each packet, a Signal Quality Error (SQE)
signal of approximately 10-bit times is generated to indi-
cate successful transmission. SQE is reported as a pulse
on the COL signal of the MII.
4.3.5 Normal Link Pulse Detection/Generation
The link pulse generator produces pulses as defined in the
IEEE 802.3 10BASE-T standard. Each link pulse is nomi-
nally 100 ns in duration and transmitted every 16 ms in the
absence of transmit data.
The SQE test is inhibited when the PHY is set in full duplex
mode. SQE can also be inhibited by setting the
HEARTBEAT_DIS bit in the 10BTSCR register.
Link pulses are used to check the integrity of the connec-
tion with the remote end. If valid link pulses are not
received, the link detector disables the 10BASE-T twisted
pair transmitter, receiver and collision detection functions.
When
the
link
integrity
function
is
disabled
(FORCE_LINK_10 of the 10BTSCR register), a good link is
forced and the 10BASE-T transceiver will operate regard-
less of the presence of link pulses.
31
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4.3.6 Jabber Function
4.3.8 Transmit and Receive Filtering
The jabber function monitors the DP83848I's output and External 10BASE-T filters are not required when using the
disables the transmitter if it attempts to transmit a packet of DP83848I, as the required signal conditioning is integrated
longer than legal size. A jabber timer monitors the transmit- into the device.
ter and disables the transmission if the transmitter is active
for approximately 85 ms.
Only isolation transformers and impedance matching resis-
tors are required for the 10BASE-T transmit and receive
Once disabled by the Jabber function, the transmitter stays interface. The internal transmit filtering ensures that all the
disabled for the entire time that the ENDEC module's inter- harmonics in the transmit signal are attenuated by at least
nal transmit enable is asserted. This signal has to be de- 30 dB.
asserted for approximately 500 ms (the “unjab” time)
before the Jabber function re-enables the transmit outputs.
The Jabber function is only relevant in 10BASE-T mode.
4.3.9 Transmitter
The encoder begins operation when the Transmit Enable
input (TX_EN) goes high and converts NRZ data to pre-
emphasized Manchester data for the transceiver. For the
duration of TX_EN, the serialized Transmit Data (TXD) is
encoded for the transmit-driver pair (PMD Output Pair).
TXD must be valid on the rising edge of Transmit Clock
(TX_CLK). Transmission ends when TX_EN deasserts.
The last transition is always positive; it occurs at the center
of the bit cell if the last bit is a one, or at the end of the bit
cell if the last bit is a zero.
4.3.7 Automatic Link Polarity Detection and Correction
The DP83848I's 10BASE-T transceiver module incorpo-
rates an automatic link polarity detection circuit. When
three consecutive inverted link pulses are received, bad
polarity is reported.
A polarity reversal can be caused by a wiring error at either
end of the cable, usually at the Main Distribution Frame
(MDF) or patch panel in the wiring closet.
The bad polarity condition is latched in the 10BTSCR regis-
ter. The DP83848I's 10BASE-T transceiver module cor-
rects for this error internally and will continue to decode
received data correctly. This eliminates the need to correct
the wiring error immediately.
4.3.10 Receiver
The decoder detects the end of a frame when no additional
mid-bit transitions are detected. Within one and a half bit
times after the last bit, carrier sense is de-asserted.
Receive clock stays active for five more bit times after CRS
goes low, to guarantee the receive timings of the controller.
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32
5.0 Design Guidelines
5.1 TPI Network Circuit
Pulse H1102
Pulse H2019
Pulse J0011D21
Pulse J0011D21B
Figure 11 shows the recommended circuit for a 10/100
Mb/s twisted pair interface. To the right is a partial list of
recommended transformers. It is important that the user
realize that variations with PCB and component character-
istics requires that the application be tested to ensure that
the circuit meets the requirements of the intended applica-
tion.
Vdd
RD-
Vdd
COMMON MODE CHOKES
MAY BE REQUIRED.
49.9Ω
0.1µF
1:1
49.9
Ω
RD+
TD-
RD-
0.1µF*
0.1µF*
RD+
TD-
TD+
Vdd
RJ45
T1
49.9Ω
1:1
0.1µF
NOTE: CENTER TAP IS PULLED TO VDD
49.9
Ω
*PLACE CAPACITORS CLOSE TO THE
TRANSFORMER CENTER TAPS
TD+
All values are typical and are +/- 1%
PLACE RESISTORS AND
CAPACITORS CLOSE TO
THE DEVICE.
Figure 11. 10/100 Mb/s Twisted Pair Interface
33
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capacitor values will vary with the crystal vendors; check
with the vendor for the recommended loads.
5.2 ESD Protection
Typically, ESD precautions are predominantly in effect
when handling the devices or board before being installed
in a system. In those cases, strict handling procedures
need be implemented during the manufacturing process to
greatly reduce the occurrences of catastrophic ESD
events. After the system is assembled, internal compo-
nents are less sensitive from ESD events.
The oscillator circuit is designed to drive a parallel reso-
nance AT cut crystal with a minimum drive level of 100µW
and a maximum of 500µW. If a crystal is specified for a
lower drive level, a current limiting resistor should be
placed in series between X2 and the crystal.
As a starting point for evaluating an oscillator circuit, if the
requirements for the crystal are not known, CL1 and CL2
should be set at 33 pF, and R1 should be set at 0Ω.
See Section 8.0 for ESD rating.
Specification for 25 MHz crystal are listed in Table 9.
5.3 Clock In (X1) Requirements
The DP83848I supports an external CMOS level oscillator
source or a crystal resonator device.
X2
X1
Oscillator
If an external clock source is used, X1 should be tied to the
clock source and X2 should be left floating.
R1
Specifications for CMOS oscillators: 25 MHz in MII Mode
and 50 MHz in RMII Mode are listed in Table 7 and Table 8.
CL1
CL2
Crystal
A 25 MHz, parallel, 20 pF load crystal resonator should be
used if a crystal source is desired. Figure 12 shows a typi-
cal connection for a crystal resonator circuit. The load
Figure 12. Crystal Oscillator Circuit
Table 7. 25 MHz Oscillator Specification
Parameter
Frequency
Frequency
Tolerance
Frequency
Stability
Min
Typ
Max
+50
+50
Units
MHz
ppm
Condition
Operational Temperature
1 year aging
25
ppm
Rise / Fall Time
Jitter
6
nsec
psec
20% - 80%
Short term
8001
8001
Jitter
psec
Long term
Symmetry
40%
60%
Duty Cycle
1 This limit is provided as a guideline for component selection and to guaranteed by production testing.
Refer to AN-1548, “PHYTER 100 Base-TX Reference Clock Jitter Tolerance,“ for details on jitter performance.
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34
Table 8. 50 MHz Oscillator Specification
Parameter
Frequency
Frequency
Tolerance
Frequency
Stability
Min
Typ
Max
+50
+50
Units
MHz
ppm
Condition
50
Operational Temperature
Operational Temperature
ppm
Rise / Fall Time
Jitter
6
nsec
psec
20% - 80%
Short term
8001
8001
Jitter
psec
Long term
Duty Cycle
Symmetry
40%
60%
1 This limit is provided as a guideline for component selection and to guaranteed by production testing.
Refer to AN-1548, “PHYTER 100 Base-TX Reference Clock Jitter Tolerance,“ for details on jitter performance.
Table 9. 25 MHz Crystal Specification
Parameter
Min
Typ
Max
Units
MHz
ppm
Condition
Frequency
25
Frequency
Tolerance
+50
+50
40
Operational
Temperature
Frequency
Stability
ppm
pF
1 year aging
Load Capacitance
25
5.4 Power Feedback Circuit
5.5 Power Down/Interrupt
To ensure correct operation for the DP83848I, parallel caps The Power Down and Interrupt functions are multiplexed
with values of 10 µF (Tantalum) and 0.1 µF should be on pin 7 of the device. By default, this pin functions as a
placed close to pin 23 (PFBOUT) of the device.
power down input and the interrupt function is disabled.
Setting bit 0 (INT_OE) of MICR (0x11h) will configure the
pin as an active low interrupt output.
Pin 18 (PFBIN1) and pin 37 (PFBIN2) must be connected
to pin 23 (PFBOUT), each pin requires a small capacitor
(.1 µF). See Figure 13 below for proper connections.
5.5.1 Power Down Control Mode
The PWR_DOWN/INT pin can be asserted low to put the
device in a Power Down mode. This is equivalent to setting
bit 11 (Power Down) in the Basic Mode Control Register,
BMCR (0x00h). An external control signal can be used to
drive the pin low, overcoming the weak internal pull-up
resistor. Alternatively, the device can be configured to ini-
tialize into a Power Down state by use of an external pull-
down resistor on the PWR_DOWN/INT pin. Since the
device will still respond to management register accesses,
setting the INT_OE bit in the MICR register will disable the
PWR_DOWN/INT input, allowing the device to exit the
Power Down state.
Pin 23 (PFBOUT
)
.1 µF
10 µF
+
-
Pin 18 (PFBIN1)
Pin 37 (PFBIN2)
.1 µF
.1 µF
5.5.2 Interrupt Mechanisms
The interrupt function is controlled via register access. All
interrupt sources are disabled by default. Setting bit 1
(INTEN) of MICR (0x11h) will enable interrupts to be out-
put, dependent on the interrupt mask set in the lower byte
of the MISR (0x12h). The PWR_DOWN/INT pin is asyn-
chronously asserted low when an interrupt condition
occurs. The source of the interrupt can be determined by
reading the upper byte of the MISR. One or more bits in the
Figure 13. Power Feeback Connection
35
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MISR will be set, denoting all currently pending interrupts.
Reading of the MISR clears ALL pending interrupts.
5.6 Energy Detect Mode
When Energy Detect is enabled and there is no activity on
the cable, the DP83848I will remain in a low power mode
while monitoring the transmission line. Activity on the line
will cause the DP83848I to go through a normal power up
sequence. Regardless of cable activity, the DP83848I will
occasionally wake up the transmitter to put ED pulses on
the line, but will otherwise draw as little power as possible.
Energy detect functionality is controlled via register Energy
Detect Control (EDCR), address 0x1Dh.
Example: To generate an interrupt on a change of link sta-
tus or on a change of energy detect power state, the steps
would be:
— Write 0003h to MICR to set INTEN and INT_OE
— Write 0060h to MISR to set ED_INT_EN and
LINK_INT_EN
— Monitor PWR_DOWN/INT pin
When PWR_DOWN/INT pin asserts low, user would read
the MISR register to see if the ED_INT or LINK_INT bits
are set, i.e. which source caused the interrupt. After read-
ing the MISR, the interrupt bits should clear and the
PWR_DOWN/INT pin will deassert.
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36
figuration values will be re-latched into the device (similar
to the power-up/reset operation).
6.0 Reset Operation
The DP83848I includes an internal power-on reset (POR)
function and does not need to be explicitly reset for normal
operation after power up. If required during normal opera-
tion, the device can be reset by a hardware or software
reset.
6.2 Software Reset
A software reset is accomplished by setting the reset bit
(bit 15) of the Basic Mode Control Register (BMCR). The
period from the point in time when the reset bit is set to the
point in time when software reset has concluded is approx-
imately 1 µs.
6.1 Hardware Reset
The software reset will reset the device such that all regis-
ters will be reset to default values and the hardware config-
uration values will be maintained. Software driver code
must wait 3 µs following a software reset before allowing
further serial MII operations with the DP83848I.
A hardware reset is accomplished by applying a low pulse
(TTL level), with a duration of at least 1 µs, to the
RESET_N. This will reset the device such that all registers
will be reinitialized to default values and the hardware con-
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37
7.0 Register Block
Table 10. Register Map
Tag
Offset
Access
Description
Hex
00h
Decimal
0
1
RW
RO
RO
RO
RW
RW
RW
RW
RW
RW
BMCR
Basic Mode Control Register
01h
BMSR
Basic Mode Status Register
02h
2
PHYIDR1
PHYIDR2
ANAR
PHY Identifier Register #1
03h
3
PHY Identifier Register #2
04h
4
Auto-Negotiation Advertisement Register
Auto-Negotiation Link Partner Ability Register (Base Page)
Auto-Negotiation Link Partner Ability Register (Next Page)
Auto-Negotiation Expansion Register
Auto-Negotiation Next Page TX
05h
5
ANLPAR
ANLPARNP
ANER
05h
5
06h
6
07h
7
ANNPTR
RESERVED
08h-Fh
8-15
RESERVED
Extended Registers
10h
11h
16
17
RO
RW
RO
RW
RO
RO
RW
RW
RW
RW
RW
RW
RW
RW
RW
PHYSTS
MICR
PHY Status Register
MII Interrupt Control Register
MII Interrupt Status Register
RESERVED
12h
18
MISR
13h
19
RESERVED
FCSCR
RECR
14h
20
False Carrier Sense Counter Register
Receive Error Counter Register
PCS Sub-Layer Configuration and Status Register
RMII and Bypass Register
LED Direct Control Register
PHY Control Register
15h
21
16h
22
PCSR
17h
23
RBR
18h
24
LEDCR
PHYCR
10BTSCR
CDCTRL1
RESERVED
EDCR
19h
25
1Ah
1Bh
1Ch
1Dh
1Eh-1Fh
26
10Base-T Status/Control Register
CD Test Control Register and BIST Extensions Register
RESERVED
27
28
29
Energy Detect Control Register
RESERVED
30-31
RESERVED
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39
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40
7.1 Register Definition
In the register definitions under the ‘Default’ heading, the following definitions hold true:
— RW=Read Write access
— SC=Register sets on event occurrence and Self-Clears when event ends
— RW/SC =Read Write access/Self Clearing bit
— RO=Read Only access
— COR = Clear on Read
— RO/COR=Read Only, Clear on Read
— RO/P=Read Only, Permanently set to a default value
— LL=Latched Low and held until read, based upon the occurrence of the corresponding event
— LH=Latched High and held until read, based upon the occurrence of the corresponding event
41
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7.1.1 Basic Mode Control Register (BMCR)
Table 12. Basic Mode Control Register (BMCR), address 0x00
Bit
Bit Name
Default
Description
15
Reset
0, RW/SC
Reset:
1 = Initiate software Reset / Reset in Process.
0 = Normal operation.
This bit, which is self-clearing, returns a value of one until the reset
process is complete. The configuration is re-strapped.
14
Loopback
0, RW
Loopback:
1 = Loopback enabled.
0 = Normal operation.
The loopback function enables MII transmit data to be routed to the MII
receive data path.
Setting this bit may cause the descrambler to lose synchronization and
produce a 500 µs “dead time” before any valid data will appear at the
MII receive outputs.
13
12
Speed Selection
Strap, RW
Strap, RW
Speed Select:
When auto-negotiation is disabled writing to this bit allows the port
speed to be selected.
1 = 100 Mb/s.
0 = 10 Mb/s.
Auto-Negotiation
Enable
Auto-Negotiation Enable:
Strap controls initial value at reset.
1 = Auto-Negotiation Enabled - bits 8 and 13 of this register are ig-
nored when this bit is set.
0 = Auto-Negotiation Disabled - bits 8 and 13 determine the port speed
and duplex mode.
11
Power Down
0, RW
Power Down:
1 = Power down.
0 = Normal operation.
Setting this bit powers down the PHY. Only the register block is en-
abled during a power down condition. This bit is OR’d with the input
from the PWR_DOWN/INT pin. When the active low
PWR_DOWN/INT pin is asserted, this bit will be set.
10
9
Isolate
0, RW
Isolate:
1 = Isolates the Port from the MII with the exception of the serial man-
agement.
0 = Normal operation.
Restart Auto-
Negotiation
0, RW/SC
Restart Auto-Negotiation:
1 = Restart Auto-Negotiation. Re-initiates the Auto-Negotiation pro-
cess. If Auto-Negotiation is disabled (bit 12 = 0), this bit is ignored. This
bit is self-clearing and will return a value of 1 until Auto-Negotiation is
initiated, whereupon it will self-clear. Operation of the Auto-Negotiation
process is not affected by the management entity clearing this bit.
0 = Normal operation.
8
Duplex Mode
Strap, RW
Duplex Mode:
When auto-negotiation is disabled writing to this bit allows the port Du-
plex capability to be selected.
1 = Full Duplex operation.
0 = Half Duplex operation.
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Table 12. Basic Mode Control Register (BMCR), address 0x00 (Continued)
Bit
Bit Name
Default
Description
7
Collision Test
0, RW
Collision Test:
1 = Collision test enabled.
0 = Normal operation.
When set, this bit will cause the COL signal to be asserted in response
to the assertion of TX_EN within 512-bit times. The COL signal will be
de-asserted within 4-bit times in response to the de-assertion of
TX_EN.
6:0
RESERVED
0, RO
RESERVED: Write ignored, read as 0.
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7.1.2 Basic Mode Status Register (BMSR)
Table 13. Basic Mode Status Register (BMSR), address 0x01
Bit
Bit Name
Default
Description
15
100BASE-T4
0, RO/P
100BASE-T4 Capable:
0 = Device not able to perform 100BASE-T4 mode.
100BASE-TX Full Duplex Capable:
14
13
12
11
100BASE-TX
Full Duplex
100BASE-TX
Half Duplex
10BASE-T
1, RO/P
1, RO/P
1, RO/P
1, RO/P
1 = Device able to perform 100BASE-TX in full duplex mode.
100BASE-TX Half Duplex Capable:
1 = Device able to perform 100BASE-TX in half duplex mode.
10BASE-T Full Duplex Capable:
Full Duplex
10BASE-T
1 = Device able to perform 10BASE-T in full duplex mode.
10BASE-T Half Duplex Capable:
Half Duplex
RESERVED
MF Preamble
Suppression
1 = Device able to perform 10BASE-T in half duplex mode.
RESERVED: Write as 0, read as 0.
10:7
6
0, RO
1, RO/P
Preamble suppression Capable:
1 = Device able to perform management transaction with preamble
suppressed, 32-bits of preamble needed only once after reset, invalid
opcode or invalid turnaround.
0 = Normal management operation.
Auto-Negotiation Complete:
5
4
Auto-Negotiation Com-
plete
0, RO
1 = Auto-Negotiation process complete.
0 = Auto-Negotiation process not complete.
Remote Fault
0, RO/LH Remote Fault:
1 = Remote Fault condition detected (cleared on read or by reset).
Fault criteria: Far End Fault Indication or notification from Link Part-
ner of Remote Fault.
0 = No remote fault condition detected.
Auto Negotiation Ability:
3
2
Auto-Negotiation Abili-
ty
1, RO/P
1 = Device is able to perform Auto-Negotiation.
0 = Device is not able to perform Auto-Negotiation.
Link Status
0, RO/LL Link Status:
1 = Valid link established (for either 10 or 100 Mb/s operation).
0 = Link not established.
The criteria for link validity is implementation specific. The occurrence
of a link failure condition will causes the Link Status bit to clear. Once
cleared, this bit may only be set by establishing a good link condition
and a read via the management interface.
1
0
Jabber Detect
0, RO/LH Jabber Detect: This bit only has meaning in 10 Mb/s mode.
1 = Jabber condition detected.
0 = No Jabber.
This bit is implemented with a latching function, such that the occur-
rence of a jabber condition causes it to set until it is cleared by a read
to this register by the management interface or by a reset.
Extended Capability
1, RO/P
Extended Capability:
1 = Extended register capabilities.
0 = Basic register set capabilities only.
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44
The PHY Identifier Registers #1 and #2 together form a unique identifier for the DP83848I. The Identifier consists of a
concatenation of the Organizationally Unique Identifier (OUI), the vendor's model number and the model revision num-
ber. A PHY may return a value of zero in each of the 32 bits of the PHY Identifier if desired. The PHY Identifier is
intended to support network management. National's IEEE assigned OUI is 080017h.
7.1.3 PHY Identifier Register #1 (PHYIDR1)
Table 14. PHY Identifier Register #1 (PHYIDR1), address 0x02
Bit
Bit Name
Default
Description
15:0
OUI_MSB
<0010 0000 0000 OUI Most Significant Bits: Bits 3 to 18 of the OUI (080017h) are
0000>, RO/P
stored in bits 15 to 0 of this register. The most significant two bits
of the OUI are ignored (the IEEE standard refers to these as bits 1
and 2).
7.1.4 PHY Identifier Register #2 (PHYIDR2)
Table 15. PHY Identifier Register #2 (PHYIDR2), address 0x03
Bit
Bit Name
Default
<0101 11>, RO/P OUI Least Significant Bits:
Bits 19 to 24 of the OUI (080017h) are mapped from bits 15 to 10
Description
15:10
OUI_LSB
of this register respectively.
9:4
3:0
VNDR_MDL
MDL_REV
<00 1001>, RO/P Vendor Model Number:
The six bits of vendor model number are mapped from bits 9 to 4
(most significant bit to bit 9).
<0000>, RO/P
Model Revision Number:
Four bits of the vendor model revision number are mapped from
bits 3 to 0 (most significant bit to bit 3). This field will be incremented
for all major device changes.
7.1.5 Auto-Negotiation Advertisement Register (ANAR)
This register contains the advertised abilities of this device as they will be transmitted to its link partner during Auto-
Negotiation.
Table 16. Negotiation Advertisement Register (ANAR), address 0x04
Bit
Bit Name
Default
Description
15
NP
0, RW
Next Page Indication:
0 = Next Page Transfer not desired.
1 = Next Page Transfer desired.
14
13
RESERVED
RF
0, RO/P
0, RW
RESERVED by IEEE: Writes ignored, Read as 0.
Remote Fault:
1 = Advertises that this device has detected a Remote Fault.
0 = No Remote Fault detected.
12
RESERVED
0, RW
RESERVED for Future IEEE use: Write as 0, Read as 0
45
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Table 16. Negotiation Advertisement Register (ANAR), address 0x04 (Continued)
Bit
Bit Name
Default
Description
11
ASM_DIR
0, RW
Asymmetric PAUSE Support for Full Duplex Links:
The ASM_DIR bit indicates that asymmetric PAUSE is supported.
Encoding and resolution of PAUSE bits is defined in IEEE 802.3
Annex 28B, Tables 28B-2 and 28B-3, respectively. Pause resolu-
tion status is reported in PHYCR[13:12].
1 = Advertise that the DTE (MAC) has implemented both the op-
tional MAC control sublayer and the pause function as specified in
clause 31 and annex 31B of 802.3u.
0= No MAC based full duplex flow control.
10
PAUSE
0, RW
PAUSE Support for Full Duplex Links:
The PAUSE bit indicates that the device is capable of providing the
symmetric PAUSE functions as defined in Annex 31B.
Encoding and resolution of PAUSE bits is defined in IEEE 802.3
Annex 28B, Tables 28B-2 and 28B-3, respectively. Pause resolu-
tion status is reported in PHYCR[13:12].
1 = Advertise that the DTE (MAC) has implemented both the op-
tional MAC control sublayer and the pause function as specified in
clause 31 and annex 31B of 802.3u.
0= No MAC based full duplex flow control.
100BASE-T4 Support:
9
8
T4
TX_FD
TX
0, RO/P
1= 100BASE-T4 is supported by the local device.
0 = 100BASE-T4 not supported.
Strap, RW
Strap, RW
Strap, RW
Strap, RW
100BASE-TX Full Duplex Support:
1 = 100BASE-TX Full Duplex is supported by the local device.
0 = 100BASE-TX Full Duplex not supported.
100BASE-TX Support:
7
1 = 100BASE-TX is supported by the local device.
0 = 100BASE-TX not supported.
6
10_FD
10
10BASE-T Full Duplex Support:
1 = 10BASE-T Full Duplex is supported by the local device.
0 = 10BASE-T Full Duplex not supported.
10BASE-T Support:
5
1 = 10BASE-T is supported by the local device.
0 = 10BASE-T not supported.
4:0
Selector
<00001>, RW Protocol Selection Bits:
These bits contain the binary encoded protocol selector supported
by this port. <00001> indicates that this device supports IEEE
802.3u.
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7.1.6 Auto-Negotiation Link Partner Ability Register (ANLPAR) (BASE Page)
This register contains the advertised abilities of the Link Partner as received during Auto-Negotiation. The content
changes after the successful auto-negotiation if Next-pages are supported.
Table 17. Auto-Negotiation Link Partner Ability Register (ANLPAR) (BASE Page), address 0x05
Bit
Bit Name
Default
Description
15
NP
0, RO
Next Page Indication:
0 = Link Partner does not desire Next Page Transfer.
1 = Link Partner desires Next Page Transfer.
Acknowledge:
14
13
ACK
RF
0, RO
0, RO
1 = Link Partner acknowledges reception of the ability data word.
0 = Not acknowledged.
The Auto-Negotiation state machine will automatically control the
this bit based on the incoming FLP bursts.
Remote Fault:
1 = Remote Fault indicated by Link Partner.
0 = No Remote Fault indicated by Link Partner.
RESERVED for Future IEEE use:
12
11
RESERVED
ASM_DIR
0, RO
0, RO
Write as 0, read as 0.
ASYMMETRIC PAUSE:
1 = Asymmetric pause is supported by the Link Partner.
0 = Asymmetric pause is not supported by the Link Partner.
PAUSE:
10
9
PAUSE
T4
0, RO
0, RO
0, RO
0, RO
0, RO
0, RO
1 = Pause function is supported by the Link Partner.
0 = Pause function is not supported by the Link Partner.
100BASE-T4 Support:
1 = 100BASE-T4 is supported by the Link Partner.
0 = 100BASE-T4 not supported by the Link Partner.
100BASE-TX Full Duplex Support:
8
TX_FD
TX
1 = 100BASE-TX Full Duplex is supported by the Link Partner.
0 = 100BASE-TX Full Duplex not supported by the Link Partner.
100BASE-TX Support:
7
1 = 100BASE-TX is supported by the Link Partner.
0 = 100BASE-TX not supported by the Link Partner.
10BASE-T Full Duplex Support:
6
10_FD
10
1 = 10BASE-T Full Duplex is supported by the Link Partner.
0 = 10BASE-T Full Duplex not supported by the Link Partner.
10BASE-T Support:
5
1 = 10BASE-T is supported by the Link Partner.
0 = 10BASE-T not supported by the Link Partner.
4:0
Selector
<0 0000>, RO Protocol Selection Bits:
Link Partner’s binary encoded protocol selector.
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7.1.7 Auto-Negotiation Link Partner Ability Register (ANLPAR) (Next Page)
Table 18. Auto-Negotiation Link Partner Ability Register (ANLPAR) (Next Page), address 0x05
Bit
Bit Name
Default
Description
15
NP
0, RO
Next Page Indication:
1 = Link Partner desires Next Page Transfer.
0 = Link Partner does not desire Next Page Transfer.
Acknowledge:
14
ACK
0, RO
1 = Link Partner acknowledges reception of the ability data word.
0 = Not acknowledged.
The Auto-Negotiation state machine will automatically control the
this bit based on the incoming FLP bursts. Software should not at-
tempt to write to this bit.
13
12
MP
0, RO
0, RO
Message Page:
1 = Message Page.
0 = Unformatted Page.
Acknowledge 2:
ACK2
1 = Link Partner does have the ability to comply to next page mes-
sage.
0 = Link Partner does not have the ability to comply to next page
message.
11
Toggle
CODE
0, RO
Toggle:
1 = Previous value of the transmitted Link Code word equalled 0.
0 = Previous value of the transmitted Link Code word equalled 1.
10:0
<00000000000>, Code:
RO
This field represents the code field of the next page transmission.
If the MP bit is set (bit 13 of this register), then the code shall be
interpreted as a “Message Page,” as defined in annex 28C of
Clause 28. Otherwise, the code shall be interpreted as an “Unfor-
matted Page,” and the interpretation is application specific.
7.1.8 Auto-Negotiate Expansion Register (ANER)
This register contains additional Local Device and Link Partner status information.
Table 19. Auto-Negotiate Expansion Register (ANER), address 0x06
Bit
15:5
4
Bit Name
RESERVED
PDF
Default
0, RO
0, RO
Description
RESERVED: Writes ignored, Read as 0.
Parallel Detection Fault:
1 = A fault has been detected via the Parallel Detection function.
0 = A fault has not been detected.
3
LP_NP_ABLE
0, RO
Link Partner Next Page Able:
1 = Link Partner does support Next Page.
0 = Link Partner does not support Next Page.
Next Page Able:
2
1
NP_ABLE
PAGE_RX
1, RO/P
1 = Indicates local device is able to send additional “Next Pages”.
Link Code Word Page Received:
0, RO/COR
1 = Link Code Word has been received, cleared on a read.
0 = Link Code Word has not been received.
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48
Table 19. Auto-Negotiate Expansion Register (ANER), address 0x06 (Continued)
Bit
Bit Name
Default
Description
0
LP_AN_ABLE
0, RO
Link Partner Auto-Negotiation Able:
1 = indicates that the Link Partner supports Auto-Negotiation.
0 = indicates that the Link Partner does not support Auto-Negotia-
tion.
7.1.9 Auto-Negotiation Next Page Transmit Register (ANNPTR)
This register contains the next page information sent by this device to its Link Partner during Auto-Negotiation.
Table 20. Auto-Negotiation Next Page Transmit Register (ANNPTR), address 0x07
Bit
Bit Name
Default
Description
15
NP
0, RW
Next Page Indication:
0 = No other Next Page Transfer desired.
1 = Another Next Page desired.
RESERVED: Writes ignored, read as 0.
Message Page:
14
13
RESERVED
MP
0, RO
1, RW
1 = Message Page.
0 = Unformatted Page.
12
11
ACK2
0, RW
0, RO
Acknowledge2:
1 = Will comply with message.
0 = Cannot comply with message.
Acknowledge2 is used by the next page function to indicate that Lo-
cal Device has the ability to comply with the message received.
TOG_TX
Toggle:
1 = Value of toggle bit in previously transmitted Link Code Word
was 0.
0 = Value of toggle bit in previously transmitted Link Code Word
was 1.
Toggle is used by the Arbitration function within Auto-Negotiation
to ensure synchronization with the Link Partner during Next Page
exchange. This bit shall always take the opposite value of the Tog-
gle bit in the previously exchanged Link Code Word.
10:0
CODE
<00000000001>, This field represents the code field of the next page transmission.
RW
If the MP bit is set (bit 13 of this register), then the code shall be
interpreted as a "Message Page”, as defined in annex 28C of IEEE
802.3u. Otherwise, the code shall be interpreted as an "Unformat-
ted Page”, and the interpretation is application specific.
The default value of the CODE represents a Null Page as defined
in Annex 28C of IEEE 802.3u.
49
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7.2 Extended Registers
7.2.1 PHY Status Register (PHYSTS)
This register provides a single location within the register set for quick access to commonly accessed information.
Table 21. PHY Status Register (PHYSTS), address 0x10
Bit
15
14
Bit Name
RESERVED
MDI-X mode
Default
0, RO
0, RO
Description
RESERVED: Write ignored, read as 0.
MDI-X mode as reported by the Auto-Negotiation logic:
This bit will be affected by the settings of the MDIX_EN and
FORCE_MDIX bits in the PHYCR register. When MDIX is en-
abled, but not forced, this bit will update dynamically as the
Auto-MDIX algorithm swaps between MDI and MDI-X configu-
rations.
1 = MDI pairs swapped
(Receive on TPTD pair, Transmit on TPRD pair)
0 = MDI pairs normal
(Receive on TRD pair, Transmit on TPTD pair)
Receive Error Latch:
13
12
Receive Error Latch
Polarity Status
0, RO/LH
This bit will be cleared upon a read of the RECR register.
1 = Receive error event has occurred since last read of RXERCNT
(address 0x15, Page 0).
0 = No receive error event has occurred.
0, RO
Polarity Status:
This bit is a duplication of bit 4 in the 10BTSCR register. This bit will
be cleared upon a read of the 10BTSCR register, but not upon a
read of the PHYSTS register.
1 = Inverted Polarity detected.
0 = Correct Polarity detected.
11
False Carrier Sense
Latch
0, RO/LH
False Carrier Sense Latch:
This bit will be cleared upon a read of the FCSR register.
1 = False Carrier event has occurred since last read of FCSCR (ad-
dress 0x14).
0 = No False Carrier event has occurred.
100Base-TX unconditional Signal Detect from PMD.
100Base-TX Descrambler Lock from PMD.
Link Code Word Page Received:
10
9
Signal Detect
Descrambler Lock
Page Received
0, RO/LL
0, RO/LL
0, RO
8
This is a duplicate of the Page Received bit in the ANER register,
but this bit will not be cleared upon a read of the PHYSTS register.
1 = A new Link Code Word Page has been received. Cleared on
read of the ANER (address 0x06, bit 1).
0 = Link Code Word Page has not been received.
7
6
MII Interrupt
0, RO
0, RO
MII Interrupt Pending:
1 = Indicates that an internal interrupt is pending. Interrupt source
can be determined by reading the MISR Register (0x12h). Reading
the MISR will clear the Interrupt.
0= No interrupt pending.
Remote Fault
Remote Fault:
1 = Remote Fault condition detected (cleared on read of BMSR (ad-
dress 01h) register or by reset). Fault criteria: notification from Link
Partner of Remote Fault via Auto-Negotiation.
0 = No remote fault condition detected.
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50
Table 21. PHY Status Register (PHYSTS), address 0x10 (Continued)
Bit
Bit Name
Default
Description
5
Jabber Detect
0, RO
Jabber Detect: This bit only has meaning in 10 Mb/s mode
This bit is a duplicate of the Jabber Detect bit in the BMSR register,
except that it is not cleared upon a read of the PHYSTS register.
1 = Jabber condition detected.
0 = No Jabber.
4
3
2
Auto-Neg Complete
Loopback Status
Duplex Status
0, RO
0, RO
0, RO
Auto-Negotiation Complete:
1 = Auto-Negotiation complete.
0 = Auto-Negotiation not complete.
Loopback:
1 = Loopback enabled.
0 = Normal operation.
Duplex:
This bit indicates duplex status and is determined from Auto-Nego-
tiation or Forced Modes.
1 = Full duplex mode.
0 = Half duplex mode.
Note: This bit is only valid if Auto-Negotiation is enabled and com-
plete and there is a valid link or if Auto-Negotiation is disabled and
there is a valid link.
1
Speed Status
0, RO
Speed10:
This bit indicates the status of the speed and is determined from
Auto-Negotiation or Forced Modes.
1 = 10 Mb/s mode.
0 = 100 Mb/s mode.
Note: This bit is only valid if Auto-Negotiation is enabled and com-
plete and there is a valid link or if Auto-Negotiation is disabled and
there is a valid link.
0
Link Status
0, RO
Link Status:
This bit is a duplicate of the Link Status bit in the BMSR register,
except that it will not be cleared upon a read of the PHYSTS regis-
ter.
1 = Valid link established (for either 10 or 100 Mb/s operation)
0 = Link not established.
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7.2.2 MII Interrupt Control Register (MICR)
This register implements the MII Interrupt PHY Specific Control register. Sources for interrupt generation include: Energy
Detect State Change, Link State Change, Speed Status Change, Duplex Status Change, Auto-Negotiation Complete or
any of the counters becoming half-full. The individual interrupt events must be enabled by setting bits in the MII Inter-
rupt Status and Event Control Register (MISR).
Table 22. MII Interrupt Control Register (MICR), address 0x11
Bit
15:3
2
Bit Name
Reserved
TINT
Default
0, RO
Description
Reserved: Write ignored, Read as 0
Test Interrupt:
0, RW
Forces the PHY to generate an interrupt to facilitate interrupt test-
ing. Interrupts will continue to be generated as long as this bit re-
mains set.
1 = Generate an interrupt
0 = Do not generate interrupt
Interrupt Enable:
1
0
INTEN
0, RW
0, RW
Enable interrupt dependent on the event enables in the MISR reg-
ister.
1 = Enable event based interrupts
0 = Disable event based interrupts
Interrupt Output Enable:
INT_OE
Enable interrupt events to signal via the PWR_DOWN/INT pin by
configuring the PWR_DOWN/INT pin as an output.
1 = PWR_DOWN/INT is an Interrupt Output
0 = PWR_DOWN/INT is a Power Down Input
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52
7.2.3 MII Interrupt Status and Misc. Control Register (MISR)
This register contains event status and enables for the interrupt function. If an event has occurred since the last read of
this register, the corresponding status bit will be set. If the corresponding enable bit in the register is set, an interrupt
will be generated if the event occurs. The MICR register controls must also be set to allow interrupts. The status indi-
cations in this register will be set even if the interrupt is not enabled
Table 23. MII Interrupt Status and Misc. Control Register (MISR), address 0x12
15
14
Reserved
ED_INT
0, RO
RESERVED: Writes ignored, Read as 0
0, RO/COR
Energy Detect interrupt:
1 = Energy detect interrupt is pending and is cleared by the current
read.
0 = No energy detect interrupt pending.
13
12
11
10
9
LINK_INT
SPD_INT
DUP_INT
ANC_INT
FHF_INT
RHF_INT
0, RO/COR
0, RO/COR
0, RO/COR
0, RO/COR
0, RO/COR
0, RO/COR
Change of Link Status interrupt:
1 = Change of link status interrupt is pending and is cleared by the
current read.
0 = No change of link status interrupt pending.
Change of speed status interrupt:
1 = Speed status change interrupt is pending and is cleared by the
current read.
0 = No speed status change interrupt pending.
Change of duplex status interrupt:
1 = Duplex status change interrupt is pending and is cleared by
the current read.
0 = No duplex status change interrupt pending.
Auto-Negotiation Complete interrupt:
1 = Auto-negotiation complete interrupt is pending and is cleared
by the current read.
0 = No Auto-negotiation complete interrupt pending.
False Carrier Counter half-full interrupt:
1 = False carrier counter half-full interrupt is pending and is
cleared by the current read.
0 = No false carrier counter half-full interrupt pending.
8
Receive Error Counter half-full interrupt:
1 = Receive error counter half-full interrupt is pending and is
cleared by the current read.
0 = No receive error carrier counter half-full interrupt pending.
RESERVED: Writes ignored, Read as 0
7
6
5
4
3
2
1
0
RESERVED
ED_INT_EN
0, RO
0, RW
0, RW
0, RW
0, RW
0, RW
0, RW
0, RW
Enable Interrupt on energy detect event
LINK_INT_EN
SPD_INT_EN
DUP_INT_EN
ANC_INT_EN
FHF_INT_EN
RHF_INT_EN
Enable Interrupt on change of link status
Enable Interrupt on change of speed status
Enable Interrupt on change of duplex status
Enable Interrupt on Auto-negotiation complete event
Enable Interrupt on False Carrier Counter Register half-full event
Enable Interrupt on Receive Error Counter Register half-full event
53
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7.2.4 False Carrier Sense Counter Register (FCSCR)
This counter provides information required to implement the “False Carriers” attribute within the MAU managed object
class of Clause 30 of the IEEE 802.3u specification.
Table 24. False Carrier Sense Counter Register (FCSCR), address 0x14
Bit
15:8
7:0
Bit Name
RESERVED
FCSCNT[7:0]
Default
0, RO
Description
RESERVED: Writes ignored, Read as 0
False Carrier Event Counter:
0, RO / COR
This 8-bit counter increments on every false carrier event. This
counter sticks when it reaches its max count (FFh).
7.2.5 Receiver Error Counter Register (RECR)
This counter provides information required to implement the “Symbol Error During Carrier” attribute within the PHY man-
aged object class of Clause 30 of the IEEE 802.3u specification.
Table 25. Receiver Error Counter Register (RECR), address 0x15
Bit
15:8
7:0
Bit Name
RESERVED
RXERCNT[7:0]
Default
0, RO
Description
RESERVED: Writes ignored, Read as 0
RX_ER Counter:
0, RO / COR
When a valid carrier is present and there is at least one occurrence
of an invalid data symbol, this 8-bit counter increments for each re-
ceive error detected. This event can increment only once per valid
carrier event. If a collision is present, the attribute will not incre-
ment. The counter sticks when it reaches its max count.
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54
7.2.6 100 Mb/s PCS Configuration and Status Register (PCSR)
Table 26. 100 Mb/s PCS Configuration and Status Register (PCSR), address 0x16
Bit
15:13
12
Bit Name
RESERVED
RESERVED
Default
<00>, RO
0
Description
RESERVED: Writes ignored, Read as 0.
RESERVED:
Must be zero.
11
10
RESERVED
TQ_EN
0
RESERVED:
Must be zero.
100Mbs True Quiet Mode Enable:
1 = Transmit True Quiet Mode.
0 = Normal Transmit Mode.
Signal Detect Force PMA:
1 = Forces Signal Detection in PMA.
0 = Normal SD operation.
Signal Detect Option:
0, RW
9
8
7
SD FORCE PMA
SD_OPTION
0, RW
1, RW
0, RW
1 = Enhanced signal detect algorithm.
0 = Reduced signal detect algorithm.
Descrambler Timeout:
DESC_TIME
Increase the descrambler timeout. When set this should allow the
device to receive larger packets (>9k bytes) without loss of syn-
chronization.
1 = 2ms
0 = 722us (per ANSI X3.263: 1995 (TP-PMD) 7.2.3.3e)
RESERVED:
6
5
RESERVED
0
Must be zero.
FORCE_100_OK
0, RW
Force 100Mb/s Good Link:
1 = Forces 100Mb/s Good Link.
0 = Normal 100Mb/s operation.
RESERVED:
4
3
2
RESERVED
RESERVED
0
0
Must be zero.
RESERVED:
Must be zero.
NRZI_BYPASS
0, RW
NRZI Bypass Enable:
1 = NRZI Bypass Enabled.
0 = NRZI Bypass Disabled.
RESERVED:
1
0
RESERVED
RESERVED
0
0
Must be zero.
RESERVED:
Must be zero.
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7.2.7 RMII and Bypass Register (RBR)
This register configures the RMII Mode of operation. When RMII mode is disabled, the RMII functionality is bypassed.
Table 27. RMII and Bypass Register (RBR), addresses 0x17
Bit
15:6
5
Bit Name
RESERVED
RMII_MODE
Default
0, RO
Description
RESERVED: Writes ignored, read as 0.
Reduced MII Mode:
Strap, RW
0 = Standard MII Mode
1 = Reduced MII Mode
4
RMII_REV1_0
0, RW
Reduce MII Revision 1.0:
0 = (RMII revision 1.2) CRS_DV will toggle at the end of a packet
to indicate deassertion of CRS.
1 = (RMII revision 1.0) CRS_DV will remain asserted until final data
is transferred. CRS_DV will not toggle at the end of a packet.
3
2
RX_OVF_STS
RX_UNF_STS
ELAST_BUF[1:0]
0, RO
0, RO
RX FIFO Over Flow Status:
0 = Normal
1 = Overflow detected
RX FIFO Under Flow Status:
0 = Normal
1 = Underflow detected
1:0
01, RW
Receive Elasticity Buffer. This field controls the Receive Elastic-
ity Buffer which allows for frequency variation tolerance between
the 50MHz RMII clock and the recovered data. The following val-
ues indicate the tolerance in bits for a single packet. The minimum
setting allows for standard Ethernet frame sizes at +/-50ppm accu-
racy for both RMII and Receive clocks. For greater frequency tol-
erance the packet lengths may be scaled (i.e. for +/-100ppm, the
packet lengths need to be divided by 2).
00 = 14 bit tolerance (up to 16800 byte packets)
01 = 2 bit tolerance (up to 2400 byte packets)
10 = 6 bit tolerance (up to 7200 byte packets)
11 = 10 bit tolerance (up to 12000 byte packets)
7.2.8 LED Direct Control Register (LEDCR)
This register provides the ability to directly control any or all LED outputs. It does not provide read access to LEDs.
Table 28. LED Direct Control Register (LEDCR), address 0x18
Bit
15:6
5
Bit Name
RESERVED
DRV_SPDLED
Default
0, RO
Description
RESERVED: Writes ignored, read as 0.
1 = Drive value of SPDLED bit onto LED_SPD output
0 = Normal operation
0, RW
4
3
DRV_LNKLED
DRV_ACTLED
0, RW
0, RW
1 = Drive value of LNKLED bit onto LED_LNK output
0 = Normal operation
1 = Drive value of ACTLED bit onto LED_ACT/COL output
0 = Normal operation
2
1
0
SPDLED
LNKLED
ACTLED
0, RW
0, RW
0, RW
Value to force on LED_SPD output
Value to force on LED_LNK output
Value to force on LED_ACT/COL output
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56
7.2.9 PHY Control Register (PHYCR)
Table 29. PHY Control Register (PHYCR), address 0x19
Bit
Bit Name
Default
Description
15
MDIX_EN
Strap, RW
Auto-MDIX Enable:
1 = Enable Auto-neg Auto-MDIX capability.
0 = Disable Auto-neg Auto-MDIX capability.
The Auto-MDIX algorithm requires that the Auto-Negotiation En-
able bit in the BMCR register to be set. If Auto-Negotiation is not
enabled, Auto-MDIX should be disabled as well.
14
13
FORCE_MDIX
PAUSE_RX
0, RW
0, RO
Force MDIX:
1 = Force MDI pairs to cross.
(Receive on TPTD pair, Transmit on TPRD pair)
0 = Normal operation.
Pause Receive Negotiated:
Indicates that pause receive should be enabled in the MAC. Based
on ANAR[11:10] and ANLPAR[11:10] settings.
This function shall be enabled according to IEEE 802.3 Annex 28B
Table 28B-3, “Pause Resolution”, only if the Auto-Negotiated High-
est Common Denominator is a full duplex technology.
12
11
PAUSE_TX
BIST_FE
0, RO
Pause Transmit Negotiated:
Indicates that pause transmit should be enabled in the MAC. Based
on ANAR[11:10] and ANLPAR[11:10] settings.
This function shall be enabled according to IEEE 802.3 Annex 28B
Table 28B-3, “Pause Resolution”, only if the Auto-Negotiated High-
est Common Denominator is a full duplex technology.
0, RW/SC
BIST Force Error:
1 = Force BIST Error.
0 = Normal operation.
This bit forces a single error, and is self clearing.
BIST Sequence select:
1 = PSR15 selected.
10
9
PSR_15
0, RW
0 = PSR9 selected.
BIST_STATUS
0, LL/RO
BIST Test Status:
1 = BIST pass.
0 = BIST fail. Latched, cleared when BIST is stopped.
For a count number of BIST errors, see the BIST Error Count in the
CDCTRL1 register.
8
7
BIST_START
BP_STRETCH
0, RW
0, RW
BIST Start:
1 = BIST start.
0 = BIST stop.
Bypass LED Stretching:
This will bypass the LED stretching and the LEDs will reflect the in-
ternal value.
1 = Bypass LED stretching.
0 = Normal operation.
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Table 29. PHY Control Register (PHYCR), address 0x19 (Continued)
Bit
6
Bit Name
Default
0, RW
Description
LED_CNFG[1]
LED_CNFG[0]
LEDs Configuration
5
LED_CNFG[1]
LED_ CNFG[0]
Mode Description
Mode 1
Strap, RW
Don’t care
1
0
0
0
1
Mode 2
Mode 3
In Mode 1, LEDs are configured as follows:
LED_LINK = ON for Good Link, OFF for No Link
LED_SPEED = ON in 100 Mb/s, OFF in 10 Mb/s
LED_ACT/COL = ON for Activity, OFF for No Activity
In Mode 2, LEDs are configured as follows:
LED_LINK = ON for good Link, BLINK for Activity
LED_SPEED = ON in 100 Mb/s, OFF in 10 Mb/s
LED_ACT/COL = ON for Collision, OFF for No Collision
Full Duplex, OFF for Half Duplex
In Mode 3, LEDs are configured as follows:
LED_LINK = ON for Good Link, BLINK for Activity
LED_SPEED = ON in 100 Mb/s, OFF in 10 Mb/s
LED_ACT/COL = ON for Full Duplex, OFF for Half Duplex
PHY Address: PHY address for port.
4:0
PHYADDR[4:0]
Strap, RW
7.2.10 10Base-T Status/Control Register (10BTSCR)
Table 30. 10Base-T Status/Control Register (10BTSCR), address 0x1A
Bit
Bit Name
Default
Description
10Base-T Serial Mode (SNI)
15
10BT_SERIAL
Strap, RW
1 = Enables 10Base-T Serial Mode
0 = Normal Operation
Places 10 Mb/s transmit and receive functions in Serial Network
Interface (SNI) Mode of operation. Has no effect on 100 Mb/s
operation.
14:12
11:9
RESERVED
SQUELCH
0, RW
RESERVED:
Must be zero.
100, RW
Squelch Configuration:
Used to set the Squelch ‘ON’ threshold for the receiver.
Default Squelch ON is 330mV peak.
8
LOOPBACK_10_D
IS
0, RW
In half-duplex mode, default 10BASE-T operation loops Transmit
data to the Receive data in addition to transmitting the data on the
physical medium. This is for consistency with earlier 10BASE2 and
10BASE5 implementations which used a shared medium. Setting
this bit disables the loopback function.
This bit does not affect loopback due to setting BMCR[14].
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58
Table 30. 10Base-T Status/Control Register (10BTSCR), address 0x1A
Bit
Bit Name
Default
Description
Normal Link Pulse Disable:
7
LP_DIS
0, RW
1 = Transmission of NLPs is disabled.
0 = Transmission of NLPs is enabled.
Force 10Mb Good Link:
1 = Forced Good 10Mb Link.
0 = Normal Link Status.
RESERVED:
6
FORCE_LINK_10
0, RW
5
4
RESERVED
POLARITY
0, RW
RO/LH
Must be zero.
10Mb Polarity Status:
This bit is a duplication of bit 12 in the PHYSTS register. Both bits
will be cleared upon a read of 10BTSCR register, but not upon a
read of the PHYSTS register.
1 = Inverted Polarity detected.
0 = Correct Polarity detected.
RESERVED:
3
2
1
RESERVED
RESERVED
0, RW
1, RW
0, RW
Must be zero.
RESERVED:
Must be set to one.
HEARTBEAT_DIS
Heartbeat Disable: This bit only has influence in half-duplex 10Mb
mode.
1 = Heartbeat function disabled.
0 = Heartbeat function enabled.
When the device is operating at 100Mb or configured for full
duplex operation, this bit will be ignored - the heartbeat func-
tion is disabled.
0
JABBER_DIS
0, RW
Jabber Disable:
Applicable only in 10BASE-T.
1 = Jabber function disabled.
0 = Jabber function enabled.
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7.2.11 CD Test and BIST Extensions Register (CDCTRL1)
Table 31. CD Test and BIST Extensions Register (CDCTRL1), address 0x1B
Bit
Bit Name
Default
Description
15:8
BIST_ERROR_CO
UNT
0, RO
BIST ERROR Counter:
Counts number of errored data nibbles during Packet BIST. This
value will reset when Packet BIST is restarted. The counter sticks
when it reaches its max count.
7:6
5
RESERVED
0, RW
0, RW
RESERVED:
Must be zero.
BIST_CONT_MOD
E
Packet BIST Continuous Mode:
Allows continuous pseudo random data transmission without any
break in transmission. This can be used for transmit VOD testing.
This is used in conjunction with the BIST controls in the PHYCR
Register (0x19h). For 10Mb operation, jabber function must be dis-
abled, bit 0 of the 10BTSCR (0x1Ah), JABBER_DIS = 1.
4
CDPATTEN_10
RESERVED
0, RW
CD Pattern Enable for 10Mb:
1 = Enabled.
0 = Disabled.
3
2
0, RW
0, RW
RESERVED:
Must be zero.
10MEG_PATT_GA
P
Defines gap between data or NLP test sequences:
1 = 15 µs.
0 = 10 µs.
1:0
CDPATTSEL[1:0]
00, RW
CD Pattern Select[1:0]:
If CDPATTEN_10 = 1:
00 = Data, EOP0 sequence
01 = Data, EOP1 sequence
10 = NLPs
11 = Constant Manchester 1s (10MHz sine wave) for harmonic dis-
tortion testing.
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60
7.2.12 Energy Detect Control (EDCR)
Table 32. Energy Detect Control (EDCR), address 0x1D
Bit
Bit Name
Default
Description
15
ED_EN
0, RW
Energy Detect Enable:
Allow Energy Detect Mode.
When Energy Detect is enabled and Auto-Negotiation is disabled
via the BMCR register, Auto-MDIX should be disabled via the PHY-
CR register.
14
13
12
ED_AUTO_UP
ED_AUTO_DOWN
ED_MAN
1, RW
1, RW
Energy Detect Automatic Power Up:
Automatically begin power up sequence when Energy Detect Data
Threshold value (EDCR[3:0]) is reached. Alternatively, device
could be powered up manually using the ED_MAN bit (ECDR[12]).
Energy Detect Automatic Power Down:
Automatically begin power down sequence when no energy is de-
tected. Alternatively, device could be powered down using the
ED_MAN bit (EDCR[12]).
0, RW/SC
Energy Detect Manual Power Up/Down:
Begin power up/down sequence when this bit is asserted. When
set, the Energy Detect algorithm will initiate a change of Energy De-
tect state regardless of threshold (error or data) and timer values.
In managed applications, this bit can be set after clearing the Ener-
gy Detect interrupt to control the timing of changing the power
state.
11
10
ED_BURST_DIS
ED_PWR_STATE
0, RW
0, RO
Energy Detect Bust Disable:
Disable bursting of energy detect data pulses. By default, Energy
Detect (ED) transmits a burst of 4 ED data pulses each time the CD
is powered up. When bursting is disabled, only a single ED data
pulse will be send each time the CD is powered up.
Energy Detect Power State:
Indicates current Energy Detect Power state. When set, Energy
Detect is in the powered up state. When cleared, Energy Detect is
in the powered down state. This bit is invalid when Energy Detect
is not enabled.
9
8
ED_ERR_MET
ED_DATA_MET
ED_ERR_COUNT
0, RO/COR
0, RO/COR
0001, RW
Energy Detect Error Threshold Met:
No action is automatically taken upon receipt of error events. This
bit is informational only and would be cleared on a read.
Energy Detect Data Threshold Met:
The number of data events that occurred met or surpassed the En-
ergy Detect Data Threshold. This bit is cleared on a read.
7:4
Energy Detect Error Threshold:
Threshold to determine the number of energy detect error events
that should cause the device to take action. Intended to allow aver-
aging of noise that may be on the line. Counter will reset after ap-
proximately 2 seconds without any energy detect data events.
3:0
ED_DATA_COUNT
0001, RW
Energy Detect Data Threshold:
Threshold to determine the number of energy detect events that
should cause the device to take actions. Intended to allow averag-
ing of noise that may be on the line. Counter will reset after approx-
imately 2 seconds without any energy detect data events.
61
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8.0 Electrical Specifications
Note: All parameters are guaranteed by test, statistical analysis or design.
Absolute Maximum Ratings
Supply Voltage (VCC
)
-0.5 V to 4.2 V
-0.5V to VCC + 0.5V
-0.5V to VCC + 0.5V
DC Input Voltage (VIN)
DC Output Voltage (VOUT
)
-65oC to 150°C
107 °C
Storage Temperature (TSTG
)
Max case temp for TA = 85°C
Max. die temperature (Tj)
150 °C
260 °C
Lead Temp. (TL)
(Soldering, 10 sec.)
ESD Rating
4.0 kV
(RZAP = 1.5k, CZAP = 100 pF)
Recommended Operating Conditions
Supply voltage (VCC
)
3.3 Volts + .3V
Industrial - Ambient Temperature (TA)
Power Dissipation (PD)
-40 to 85 °C
267 mW
Absolute maximum ratings are those values beyond which the safety of the device cannot be guaranteed. They are not
meant to imply that the device should be operated at these limits.
Max
Units
Thermal Characteristic
Theta Junction to Case (Tjc)
28.7
°C / W
Theta Junction to Ambient (Tja) degrees Celsius/Watt - No Airflow @ 1.0W
Note: This is done with a JEDEC (2 layer 2 oz CU.) thermal test board
83.6
°C / W
8.1 DC Specs
Symbol
VIH
Pin Types
Parameter
Conditions
Min
Typ
Max
Units
I
Input High Voltage Nominal VCC
2.0
V
I/O
VIL
IIH
I
Input Low Voltage
0.8
10
V
I/O
I
Input High Current VIN = VCC
Input Low Current VIN = GND
µA
µA
V
I/O
IIL
I
10
I/O
VOL
VOH
IOZ
O,
I/O
Output Low
Voltage
IOL = 4 mA
IOH = -4 mA
VOUT = VCC
0.4
O,
I/O
Output High
Voltage
Vcc - 0.5
V
I/O,
O
TRI-STATE
Leakage
+ 10
µA
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62
Symbol
Pin Types
Parameter
Conditions
Min
Typ
Max
Units
VTPTD_100 PMD Output 100M Transmit
0.95
1
1.05
V
Pair Voltage
VTPTDsym PMD Output 100M Transmit
Pair Voltage Symmetry
+ 2
2.8
%
VTPTD_10
CIN1
COUT1
SDTHon
PMD Output 10M Transmit
2.2
2.5
5
V
Pair
Voltage
I
CMOS Input
Capacitance
pF
pF
O
CMOS Output
Capacitance
5
PMD Input
Pair
100BASE-TX
Signal detect turn-
on threshold
1000
585
mV diff pk-pk
SDTHoff
PMD Input
Pair
100BASE-TX
Signal detect turn-
off threshold
200
mV diff pk-pk
VTH1
Idd100
Idd10
Idd
PMD Input
Pair
10BASE-T Re-
ceive Threshold
mV
mA
mA
mA
Supply
Supply
Supply
100BASE-TX
(Full Duplex)
81
92
14
10BASE-T
(Full Duplex)
Power Down
Mode
63
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8.2 AC Specs
8.2.1 Power Up Timing
Vcc
X1 clock
T2.1.1
Hardware
RESET_N
32 clocks
MDC
T2.1.2
Latch-In of Hardware
Configuration Pins
T2.1.3
input
output
Dual Function Pins
Become Enabled As Outputs
Parameter
Description
Post Power Up Stabilization
Notes
Min
Typ Max Units
T2.1.1
MDIO is pulled high for 32-bit serial man- 167
ms
time prior to MDC preamble for agement initialization
register accesses
X1 Clock must be stable for a min. of
167ms at power up.
T2.1.2
T2.1.3
Hardware Configuration Latch- Hardware Configuration Pins are de-
167
ms
in Time from power up
scribed in the Pin Description section
X1 Clock must be stable for a min. of
167ms at power up.
Hardware Configuration pins
transition to output drivers
50
ns
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64
8.2.2 Reset Timing
Vcc
X1 clock
T2.2.1
T2.2.4
Hardware
RESET_N
32 clocks
MDC
T2.2.2
Latch-In of Hardware
Configuration Pins
T2.2.3
input
output
Dual Function Pins
Become Enabled As Outputs
Parameter
Description
Notes
Min
Typ Max Units
T2.2.1
Post RESET Stabilization time MDIO is pulled high for 32-bit serial man-
prior to MDC preamble for reg- agement initialization
ister accesses
3
µs
T2.2.2
Hardware Configuration Latch- Hardware Configuration Pins are de-
in Time from the Deassertion scribed in the Pin Description section
of RESET (either soft or hard)
3
µs
T2.2.3
T2.2.4
Hardware Configuration pins
transition to output drivers
50
ns
RESET pulse width
X1 Clock must be stable for at min. of 1us
during RESET pulse low time.
1
µs
Note: It is important to choose pull-up and/or pull-down resistors for each of the hardware configuration pins that provide
fast RC time constants in order to latch-in the proper value prior to the pin transitioning to an output driver.
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8.2.3 MII Serial Management Timing
MDC
T2.3.1
T2.3.4
MDIO (output)
MDC
T2.3.2
T2.3.3
Valid Data
MDIO (input)
Parameter
T2.3.1
Description
Notes
Min
0
Typ
Max
Units
ns
MDC to MDIO (Output) Delay Time
MDIO (Input) to MDC Setup Time
MDIO (Input) to MDC Hold Time
MDC Frequency
30
T2.3.2
10
10
ns
T2.3.3
ns
T2.3.4
2.5
25
MHz
8.2.4 100 Mb/s MII Transmit Timing
T2.4.1
T2.4.1
TX_CLK
T2.4.3
T2.4.2
TXD[3:0]
TX_EN
Valid Data
Parameter
T2.4.1
Description
Notes
Min Typ Max Units
TX_CLK High/Low Time
100 Mb/s Normal mode
100 Mb/s Normal mode
16
10
20
24
ns
ns
T2.4.2
TXD[3:0], TX_EN Data Setup to TX_CLK
T2.4.3
TXD[3:0], TX_EN Data Hold from TX_CLK 100 Mb/s Normal mode
0
ns
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66
8.2.5 100 Mb/s MII Receive Timing
T2.5.1
T2.5.1
RX_CLK
T2.5.2
RXD[3:0]
RX_DV
RX_ER
Valid Data
Parameter
T2.5.1
Description
RX_CLK High/Low Time
RX_CLK to RXD[3:0], RX_DV, RX_ER Delay 100 Mb/s Normal mode
Notes
Min Typ Max Units
100 Mb/s Normal mode
16
10
20
24
30
ns
ns
T2.5.2
Note: RX_CLK may be held low or high for a longer period of time during transition between reference and recovered
clocks. Minimum high and low times will not be violated.
8.2.6 100BASE-TX Transmit Packet Latency Timing
TX_CLK
TX_EN
TXD
T2.6.1
IDLE
(J/K)
DATA
PMD Output Pair
Parameter
Description
Notes
Min
Typ Max
Units
T2.6.1
TX_CLK to PMD Output Pair 100 Mb/s Normal mode
Latency
6
bits
Note: For Normal mode, latency is determined by measuring the time from the first rising edge of TX_CLK occurring after
the assertion of TX_EN to the first bit of the “J” code group as output from the PMD Output Pair. 1 bit time = 10 ns in 100
Mb/s mode.
67
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8.2.7 100BASE-TX Transmit Packet Deassertion Timing
TX_CLK
TX_EN
TXD
T2.7.1
PMD Output Pair
DATA
(T/R)
IDLE
Parameter
Description
Notes
Min
Typ Max Units
bits
T2.7.1
TX_CLK to PMD Output Pair 100 Mb/s Normal mode
Deassertion
6
Note: Deassertion is determined by measuring the time from the first rising edge of TX_CLK occurring after the deasser-
tion of TX_EN to the first bit of the “T” code group as output from the PMD Output Pair. 1 bit time = 10 ns in 100 Mb/s mode.
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68
8.2.8 100BASE-TX Transmit Timing (tR/F & Jitter)
T2.8.1
+1 rise
90%
10%
PMD Output Pair
10%
90%
+1 fall
T2.8.1
-1 fall
-1 rise
T2.8.1
T2.8.1
T2.8.2
PMD Output Pair
eye pattern
T2.8.2
Parameter
Description
Notes
Min
Typ Max Units
T2.8.1
100 Mb/s PMD Output Pair tR
and tF
3
4
5
ns
100 Mb/s tR and tF Mismatch
500
1.4
ps
ns
T2.8.2
100 Mb/s PMD Output Pair
Transmit Jitter
Note: Normal Mismatch is the difference between the maximum and minimum of all rise and fall times
Note: Rise and fall times taken at 10% and 90% of the +1 or -1 amplitude
69
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8.2.9 100BASE-TX Receive Packet Latency Timing
PMD Input Pair
IDLE
(J/K)
Data
T2.9.1
CRS
T2.9.2
RXD[3:0]
RX_DV
RX_ER
Parameter
T2.9.1
Description
Carrier Sense ON Delay
Receive Data Latency
Notes
Min
Typ Max
Units
bits
100 Mb/s Normal mode
100 Mb/s Normal mode
20
24
T2.9.2
bits
Note: Carrier Sense On Delay is determined by measuring the time from the first bit of the “J” code group to the assertion
of Carrier Sense.
Note: 1 bit time = 10 ns in 100 Mb/s mode
Note: PMD Input Pair voltage amplitude is greater than the Signal Detect Turn-On Threshold Value.
8.2.10 100BASE-TX Receive Packet Deassertion Timing
PMD Input Pair
CRS
DATA
(T/R)
IDLE
T2.10.1
Parameter
T2.10.1
Description
Carrier Sense OFF Delay
Notes
100 Mb/s Normal mode
Min
Typ Max
Units
24
bits
Note: Carrier Sense Off Delay is determined by measuring the time from the first bit of the “T” code group to the deasser-
tion of Carrier Sense.
Note: 1 bit time = 10 ns in 100 Mb/s mode
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70
8.2.11 10 Mb/s MII Transmit Timing
T2.11.1
T2.11.1
TX_CLK
T2.11.2
T2.11.3
TXD[3:0]
TX_EN
Valid Data
Parameter
T2.11.1
Description
TX_CLK High/Low Time
Notes
Min Typ Max Units
10 Mb/s MII mode
10 Mb/s MII mode
10 Mb/s MII mode
190 200 210
ns
ns
ns
T2.11.2
TXD[3:0], TX_EN Data Setup to TX_CLK fall
TXD[3:0], TX_EN Data Hold from TX_CLK rise
25
0
T2.11.3
Note: An attached Mac should drive the transmit signals using the positive edge of TX_CLK. As shown above, the MII
signals are sampled on the falling edge of TX_CLK.
8.2.12 10 Mb/s MII Receive Timing
T2.12.1
T2.12.1
RX_CLK
T2.12.3
T2.12.2
RXD[3:0]
RX_DV
Valid Data
Parameter
T2.12.1
Description
Notes
Min Typ Max Units
RX_CLK High/Low Time
160 200
100
240
ns
ns
ns
T2.12.2
RX_CLK to RXD[3:0], RX_DV Delay
10 Mb/s MII mode
10 Mb/s MII mode
T2.12.3
RX_CLK rising edge delay from RXD[3:0],
RX_DV Valid
100
Note: RX_CLK may be held low for a longer period of time during transition between reference and recovered clocks.
Minimum high and low times will not be violated.
71
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8.2.13 10 Mb/s Serial Mode Transmit Timing
T2.13.2
T2.13.1
TX_CLK
T2.13.4
T2.13.3
TXD[0]
TX_EN
Valid Data
Parameter
T2.13.1
Description
TX_CLK High Time
Notes
Min Typ Max Units
10 Mb/s Serial mode
10 Mb/s Serial mode
10 Mb/s Serial mode
10 Mb/s Serial mode
20
70
25
0
25
75
30
80
ns
ns
ns
ns
T2.13.2
TX_CLK Low Time
T2.13.3
TXD_0, TX_EN Data Setup to TX_CLK rise
TXD_0, TX_EN Data Hold from TX_CLK rise
T2.13.4
8.2.14 10 Mb/s Serial Mode Receive Timing
T2.14.1
T2.14.1
RX_CLK
T2.14.2
RXD[0]
RX_DV
Valid Data
Parameter
T2.14.1
Description
RX_CLK High/Low Time
RX_CLK fall to RXD_0, RX_DV Delay
Notes
Min Typ Max Units
35
50
65
10
ns
ns
T2.14.2
10 Mb/s Serial mode
-10
Note: RX_CLK may be held high for a longer period of time during transition between reference and recovered clocks.
Minimum high and low times will not be violated.
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72
8.2.15 10BASE-T Transmit Timing (Start of Packet)
TX_CLK
TX_EN
TXD
T2.15.2
PMD Output Pair
T2.15.1
Parameter
Description
Notes
Min
Typ
Max
Units
T2.15.1
Transmit Output Delay from the
Falling Edge of TX_CLK
10 Mb/s MII mode
3.5
bits
T2.15.2
Transmit Output Delay from the
Rising Edge of TX_CLK
10 Mb/s Serial mode
3.5
bits
Note: 1 bit time = 100 ns in 10Mb/s.
8.2.16 10BASE-T Transmit Timing (End of Packet)
TX_CLK
TX_EN
T2.16.1
0
0
PMD Output Pair
T2.16.2
PMD Output Pair
1
1
Parameter
Description
Notes
Min
Typ Max Units
T2.16.1
End of Packet High Time
(with ‘0’ ending bit)
250
300
ns
T2.16.2
End of Packet High Time
(with ‘1’ ending bit)
250
300
ns
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8.2.17 10BASE-T Receive Timing (Start of Packet)
1st SFD bit decoded
1
0
1
0
1
0
1
0
1
0
1
1
TPRD±
T2.17.1
CRS
RX_CLK
T2.17.2
RX_DV
T2.17.3
0000
Preamble
SFD
Data
RXD[3:0]
Parameter
Description
Notes
Min
Typ Max Units
T2.17.1
Carrier Sense Turn On Delay (PMD
Input Pair to CRS)
630 1000
ns
T2.17.2
T2.17.3
RX_DV Latency
10
8
bits
bits
Receive Data Latency
Measurement shown from SFD
Note: 10BASE-T RX_DV Latency is measured from first bit of preamble on the wire to the assertion of RX_DV
Note: 1 bit time = 100 ns in 10 Mb/s mode.
8.2.18 10BASE-T Receive Timing (End of Packet)
1
IDLE
0
1
PMD Input Pair
RX_CLK
T2.18.1
CRS
Parameter
Description
Carrier Sense Turn Off Delay
Notes
Min
Typ Max Units
T2.18.1
1.0
µs
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74
8.2.19 10 Mb/s Heartbeat Timing
TX_EN
TX_CLK
COL
T2.19.2
T2.19.1
Parameter
T2.19.1
Description
Notes
Min
Typ Max Units
CD Heartbeat Delay
All 10 Mb/s modes
All 10 Mb/s modes
1200
1000
ns
ns
T2.19.2
CD Heartbeat Duration
8.2.20 10 Mb/s Jabber Timing
TXE
T2.20.1
T2.20.2
PMD Output Pair
COL
Parameter
T2.20.1
Description
Jabber Activation Time
Jabber Deactivation Time
Notes
Min
Typ Max Units
85
ms
ms
T2.20.2
500
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8.2.21 10BASE-T Normal Link Pulse Timing
T2.21.2
T2.21.1
Normal Link Pulse(s)
Parameter
Description
Notes
Min
Typ Max Units
T2.21.1
T2.21.2
Pulse Width
Pulse Period
100
16
ns
ms
Note: These specifications represent transmit timings.
8.2.22 Auto-Negotiation Fast Link Pulse (FLP) Timing
T2.22.2
T2.22.3
T2.22.1
T2.22.1
Fast Link Pulse(s)
clock
pulse
data
pulse
clock
pulse
T2.22.5
T2.22.4
FLP Burst
FLP Burst
Parameter
T2.22.1
Description
Notes
Min
Typ Max Units
Clock, Data Pulse Width
100
125
ns
T2.22.2
Clock Pulse to Clock Pulse
Period
µs
T2.22.3
Clock Pulse to Data Pulse
Period
Data = 1
62
µs
T2.22.4
T2.22.5
Burst Width
2
ms
ms
FLP Burst to FLP Burst Period
16
Note: These specifications represent transmit timings.
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76
8.2.23 100BASE-TX Signal Detect Timing
PMD Input Pair
T2.23.1
T2.23.2
SD+ internal
Parameter
T2.23.1
Description
Notes
Min
Typ Max Units
SD Internal Turn-on Time
SD Internal Turn-off Time
1
ms
T2.23.2
350
µs
Note: The signal amplitude on PMD Input Pair must be TP-PMD compliant.
8.2.24 100 Mb/s Internal Loopback Timing
TX_CLK
TX_EN
TXD[3:0]
CRS
T2.24.1
RX_CLK
RX_DV
RXD[3:0]
Parameter
Description
Notes
Min
Typ Max Units
240 ns
T2.24.1
TX_EN to RX_DV Loopback
100 Mb/s internal loopback mode
Note1: Due to the nature of the descrambler function, all 100BASE-TX Loopback modes will cause an initial “dead-time”
of up to 550 µs during which time no data will be present at the receive MII outputs. The 100BASE-TX timing specified is
based on device delays after the initial 550µs “dead-time”.
Note2: Measurement is made from the first rising edge of TX_CLK after assertion of TX_EN.
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8.2.25 10 Mb/s Internal Loopback Timing
TX_CLK
TX_EN
TXD[3:0]
CRS
T2.25.1
RX_CLK
RX_DV
RXD[3:0]
Parameter
Description
Notes
Min
Typ Max Units
µs
T2.25.1
TX_EN to RX_DV Loopback 10 Mb/s internal loopback mode
2
Note: Measurement is made from the first rising edge of TX_CLK after assertion of TX_EN.
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78
8.2.26 RMII Transmit Timing
T2.26.1
X1
T2.26.2
T2.26.3
TXD[1:0]
TX_EN
Valid Data
T2.26.4
Symbol
PMD Output Pair
Parameter
T2.26.1
Description
X1 Clock Period
Notes
50 MHz Reference Clock
Min Typ Max Units
20
ns
ns
T2.26.2
TXD[1:0], TX_EN, DataSetup
to X1 rising
4
2
T2.26.3
T2.26.4
TXD[1:0], TX_EN, Data Hold
from X1 rising
ns
X1 Clock to PMD Output Pair From X1 Rising edge to first bit of symbol
Latency
17
bits
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8.2.27 RMII Receive Timing
IDLE
(J/K)
Data
(TR)
Data
PMD Input Pair
T2.27.4
T2.27.5
X1
T2.27.1
T2.27.2
T2.27.2
T2.27.3
T2.27.2
RX_DV
CRS_DV
T2.27.2
RXD[1:0]
RX_ER
Parameter
Description
X1 Clock Period
Notes
Min Typ Max Units
T2.27.1
T2.27.2
50 MHz Reference Clock
20
ns
ns
RXD[1:0], CRS_DV, RX_DV
and RX_ER output delay from
X1 rising
2
14
T2.27.3
T2.27.4
T2.27.5
CRS ON delay
From JK symbol on PMD Receive Pair to
initial assertion of CRS_DV
18.5
27
bits
bits
bits
CRS OFF delay
From TR symbol on PMD Receive Pair to
initial deassertion of CRS_DV
RXD[1:0] and RX_ER latency From symbol on Receive Pair. Elasticity
buffer set to default value (01)
38
Note: Per the RMII Specification, output delays assume a 25pF load.
Note: CRS_DV is asserted asynchronously in order to minimize latency of control signals through the why. CRS_DV may
toggle synchronously at the end of the packet to indicate CRS deassertion.
Note: RX_DV is synchronous to X1. While not part of the RMII specification, this signal is provided to simplify recovery of
receive data.
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8.2.28 Isolation Timing
Clear bit 10 of BMCR
(return to normal operation
from Isolate mode)
T2.28.1
T2.28.2
H/W or S/W Reset
(with PHYAD = 00000)
MODE
NORMAL
ISOLATE
Parameter
Description
Notes
Min
Typ Max Units
T2.28.1
From software clear of bit 10 in
the BMCR register to the transi-
tion from Isolate to Normal Mode
100
µs
T2.28.2
From Deassertion of S/W or H/W
Reset to transition from Isolate to
Normal mode
500
µs
8.2.29 25 MHz_OUT Timing
X1
T2.29.2
T2.29.1
T2.29.1
25 MHz_OUT
Parameter
Description
Notes
Min Typ Max Units
T2.29.1
25 MHz_OUT High/Low Time
MII mode
20
10
ns
ns
ns
RMII mode
T2.29.2
25 MHz_OUT propagation delay
Relative to X1
8
Note: 25 MHz_OUT characteristics are dependent upon the X1 input characteristics.
81
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8.2.30 100 Mb/s X1 to TX_CLK Timing
X1
T2.30.1
TX_CLK
Parameter
Description
X1 to TX_CLK delay
Notes
Min Typ Max Units
ns
T2.30.1
100 Mb/s Normal mode
0
5
Note: X1 to TX_CLK timing is provided to support devices that use X1 instead of TX_CLK as the reference for transmit
Mll data.
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82
Notes:
83
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inches (millimeters) unless otherwise noted
9.0 Physical Dimensions
Lead Quad Frame Package (LQFP)
NS Package Number VBH48A
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