NSC DP83843 Phyter Datasheet

DP83843BVJE PHYTER
General Description
Features
The DP83843BVJE is a full feature Physical Layer device — IEEE 802.3 ENDEC with AUI/10BASE-T transceivers
with integrated PMD sublayers to support both 10BASE-T
and built-in filters
and 100BASE-X Ethernet protocols.
— IEEE 802.3u 100BASE-TX compatible - directly drives
standard Category 5 UTP, no need for external
This VLSI device is designed for easy implementation of
100BASE-TX transceiver
10/100 Mb/s Ethernet LANs. It interfaces directly to Twisted
Pair media through an external transformer or to fiber — Fully Integrated and fully compliant ANSI X3.263 TPmedia via industry standard electrical/optical fiber PMD
PMD physical sublayer which includes adaptive equaltransceivers. This device also interfaces directly to the
ization and BLW compensation
MAC layer through the IEEE 802.3u standard Media Inde— IEEE 802.3u 100BASE-FX compatible - connects directpendent Interface (MII), ensuring interoperability between
ly to industry standard Electrical/Optical transceivers
products from different vendors.
— IEEE 802.3u Auto-Negotiation for automatic speed seThe DP83843 is designed with National Semiconductor's
lection
advanced CMOS process. Its system architecture is based
on the integration of several of National's industry proven — IEEE 802.3u compatible Media Independent Interface
(MII) with Serial Management Interface
core technologies:
—
Integrated
high performance 100 Mb/s clock recovery
— IEEE 802.3 ENDEC with AUI/10BASE-T transceiver
circuitry
requiring
no external filters
module to provide the 10 Mb/s functions
—
Full
Duplex
support
for 10 and 100 Mb/s data rates
— Clock Recovery/Generator Modules from National's Fast
—
MII
Serial
10
Mb/s
mode
Ethernet and FDDI products
— Fully configurable node/switch and 100Mb/s repeater
— FDDI Stream Cipher scrambler/descrambler for
modes
TP-PMD
—
Programmable
loopback modes for flexible system diag— 100BASE-X physical coding sub-layer (PCS) and control
nostics
logic that integrates the core modules into a dual speed
Ethernet physical layer controller
— Flexible LED support
— ANSI X3T12 Compliant TP-PMD Transceiver
— Single register access to complete PHY status
technology with Baseline Wander (BLW) compensation
— MDIO interrupt support
— Individualized scrambler seed for 100BASE-TX applications using multiple PHYs
— Low power consumption for multi-port applications
— Small footprint 80-pin PQFP package
10BASE-T or
100BASE-TX
MII
10 AND/OR 100 Mb/s
ETHERNET MAC OR
100Mb/s REPEATER
CONTROLLER
DP83843
10/100 Mb/s
ETHERNET PHYSICAL LAYER
25 MHz
CLOCK
MAGNETICS
System Diagram
RJ-45
10BASE-T
or
100BASE-TX
STATUS
LEDS
100BASE-FX/
AUI
ThunderLAN® is a registered trademark of Texas Instruments.
TWISTER™ is a trademark of National Semiconductor Corporation.
TRI-STATE® is a registered trademark of National Semiconductor Corporation.
© 1999 National Semiconductor Corporation
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DP83843BVJE PHYTER
July 1999
Block Diagram
MII
HARDWARE
CONFIGURATION
PINS
RX_CL
RXD[3:0]
RX_DV
RX_ER
RX_EN
CRS
COL
MDC
MDIO
TX_EN
TX_ER
(REPEATER,
SERIAL10, SYMBOL,
,
AN0, AN1,FXEN
PHYAD[4:0])
TXD[3:0]
TX_CLK
SERIAL
MANAGEMENT
MII INTERFACE/CONTROL
RX_DATA
RX_CLK
TX_DATA
TX_DATA
4B/5B
ENCODER
SCRAMBLER
REGISTERS
MII
10 MB/S
PHY ADDRESS
NRZ TO
MANCHESTER
ENCODER
AUTO
NEGOTIATION
PARALLEL TO
SERIAL
LINK PULSE
GENERATOR
NRZ TO NRZI
ENCODER
BINARY TO
MLT-3
ENCODER
RX_CLK
TX_CLK
TRANSMIT CHANNELS &
STATE MACHINES
100 MB/S
RX_DATA
RECEIVE CHANNELS &
STATE MACHINES
100 MB/S
4B/5B
DECODER
NODE/RPTR
CODE GROUP
ALIGNMENT
PCS CONTROL
DESCRAMBLER
10BASE-T
SERIAL TO
PARALLEL
10 MB/S
MANCHESTER
TO NRZ
DECODER
CLOCK
RECOVERY
100BASE-X
NRZI TO NRZ
DECODER
TRANSMIT
FILTER
FAR-END-FAULT
STATE MACHINE
10/100 COMMON
OUTPUT DRIVER
AUTO-NEGOTIATION
STATE MACHINE
LINK PULSE
DETECTOR
CLOCK
RECOVERY
MLT-3 TO
BINARY
DECODER
ADAPTIVE
EQ
AND
BLW
COMP.
RECEIVE
FILTER
SMART
SQUELCH
10/100 COMMON
INPUT BUFFER
CLOCK
GENERATION
LED
DRIVERS
TPTD+/−
FXTD/AUITD+/−
TXAR100
TPRD+/−
FXRD/AUIRD+/−
LEDS
SYSTEM CLOCK
REFERENCE
2
FXSD/CD+/−
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Table of Contents
1.0
2.0
3.0
4.0
5.0
6.0
Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1
MII Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2
10 Mb/s and 100 Mb/s PMD Interface . . . . . . . . . . 6
1.3
Clock Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4
Device Configuration Interface . . . . . . . . . . . . . . . 8
1.5
LED Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.6
PHY Address Interface . . . . . . . . . . . . . . . . . . . . 11
1.7
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.8
Power And Ground Pins . . . . . . . . . . . . . . . . . . . 12
1.9
Special Connect Pins . . . . . . . . . . . . . . . . . . . . . . 12
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1
802.3u MII . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2
100BASE-TX TRANSMITTER . . . . . . . . . . . . . . . 15
2.3
100BASE-TX RECEIVER . . . . . . . . . . . . . . . . . . 18
2.4
10BASE-T TRANSCEIVER MODULE . . . . . . . . . 22
2.5
100 BASE-FX . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.6
AUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1
Auto-Negotiation . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.2
PHY Address and LEDs . . . . . . . . . . . . . . . . . . . 30
3.3
Half Duplex vs. Full Duplex . . . . . . . . . . . . . . . . . 31
3.4
100 Mb/s Symbol Mode . . . . . . . . . . . . . . . . . . . . 32
3.5
100BASE-FX Mode . . . . . . . . . . . . . . . . . . . . . . . 32
3.6
10 Mb/s Serial Mode . . . . . . . . . . . . . . . . . . . . . . 32
3.7
10 Mb/s AUI Mode . . . . . . . . . . . . . . . . . . . . . . . . 32
3.8
Repeater vs. Node . . . . . . . . . . . . . . . . . . . . . . . . 33
3.9
Isolate Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.10 Loopback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Clock Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.1
Clock Generation Module (CGM) . . . . . . . . . . . . 34
4.2
100BASE-X Clock Recovery Module . . . . . . . . . . 36
4.3
10 Mb/s Clock Recovery Module . . . . . . . . . . . . . 36
4.4
Reference Clock Connection Options . . . . . . . . . 36
Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.1
Power-up / Reset . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.2
Hardware Reset . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.3
Software Reset . . . . . . . . . . . . . . . . . . . . . . . . . . 37
DP83843 Application . . . . . . . . . . . . . . . . . . . . . . . . . . 38
6.1
Typical Node Application . . . . . . . . . . . . . . . . . . . 38
6.2
Power And Ground Filtering . . . . . . . . . . . . . . . . 38
6.3
Power Plane Considerations . . . . . . . . . . . . . . . . 38
7.0
8.0
9.0
10.0
11.0
3
User Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
7.1
Link LED While in Force 100Mb/s Good Link . . . 42
7.2
False Link Indication When in Forced 10Mb/s . . 42
7.3
10Mb/s Repeater Mode . . . . . . . . . . . . . . . . . . . 42
7.4
Resistor Value Modifications . . . . . . . . . . . . . . . 42
7.5
Magnetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
7.6
Next Page Toggle Bit Initialization . . . . . . . . . . . 43
7.7
Base Page to Next Page Initial FLP Burst Spacing
43
7.8
100Mb/s FLP Exchange Followed by Quiet . . . . 43
7.9
Common Mode Capacitor for EMI improvement 44
7.10 BAD_SSD Event Lockup . . . . . . . . . . . . . . . . . . 44
Register Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
8.1
Register Definitions . . . . . . . . . . . . . . . . . . . . . . 45
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . 63
9.1
DC Electrical Specification . . . . . . . . . . . . . . . . . 64
9.2
CGM Clock Timing . . . . . . . . . . . . . . . . . . . . . . 66
9.3
MII Serial Management AC Timing . . . . . . . . . . 66
9.4
100 Mb/s AC Timing . . . . . . . . . . . . . . . . . . . . . . 67
9.5
10 Mb/s AC Timing . . . . . . . . . . . . . . . . . . . . . . . 74
9.6
Auto-Negotiation Fast Link Pulse (FLP) Timing 80
9.7
100BASE-X Clock Recovery Module (CRM) Timing
80
9.8
Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . 82
9.9
Loopback Timing . . . . . . . . . . . . . . . . . . . . . . . 83
9.10 Isolation Timing . . . . . . . . . . . . . . . . . . . . . . . . 84
Test Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
10.1 FXTD/AUITD+/- Outputs (sourcing AUI levels) . 85
10.2 FXTD/AUITD+/- Outputs (sourcing PECL) . . . . . 85
10.3 CMOS Outputs (MII and LED) . . . . . . . . . . . . . . 85
10.4 TPTD+/- Outputs (sourcing 10BASE-T) . . . . . . . 85
10.5 TPTD+/- Outputs (sourcing 100BASE-TX) . . . . . 85
10.6 Idd Measurement Conditions . . . . . . . . . . . . . . . 85
Package Dimensions inches (millimeters) unless otherwise noted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
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LED_TX/PHYAD[1]
LED_COL/PHYAD[0]
FXTD-/AUITD-
FXTD+/AUITD+
AUIFX_GND
FXSD-/CD-
AUIFX_VDD
FXSD+/CD+
FXRD-/AUIRD-
CP_AGND
FXRD+/AUIRD+
CP_AVDD
CPTW_DVSS
NC
CPTW_DVDD
NC
ATP_GND
NC
NC
TWREF
Connection Diagram
BGREF
61
60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41
40
NC
62
39
THIN/REPEATER
63
38
LED_FDPOL/PHYAD[4]
TW_AGND
64
37
IO_VSS5
TPRD-
65
36
IO_VDD5
VCM_CAP
66
35
MDC
MDIO
TX_CLK
LED_RX/PHYAD[2]
LED_LINK/PHYAD[3]
TPRD+
67
34
TW_AVDD
68
33
SERIAL10
69
32
IO_VSS4
SUB_GND1
70
31
TXD[0]
CD_GND0
71
30
TXD[1]
CD_VDD0
72
29
TXD[2]
TPTD-
73
28
TXD[3]
IO_VSS3
DP83843BVJE
PHYTER
77
24
TX_ER
TXAR100
78
23
RX_EN
TR_AVDD
79
22
CRS/SYMBOL
TR_AGND
80
21
COL/FXEN
RX_DV
RX_ER
RX_CLK
9 10 11 12 13 14 15 16 17 18 19 20
IO_VSS2
8
IO_VDD2
7
RXD[0]
6
RXD[1]
5
RXD[2]
4
RXD[3]
3
PCS_VSS
2
PCS_VDD
1
X1
SUB_GND2
X2
TX_EN
IO_VSS1
25
IO_VDD1
76
AN0
IO_VDD3
CD_VDD1
SPEED10
26
AN1
27
75
NC
74
RESET
TPTD+
CD_GND1
Order Number DP83843BVJE
NS Package Number VJE80
4
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1.0 Pin Descriptions
The DP83843 pins are classified into the following interface — DEVICE CONFIGURATION INTERFACE
categories. Each interface is described in the sections that — LED INTERFACE
follow.
— PHY ADDRESS INTERFACE
— MII INTERFACE
— RESET
— 10/100 Mb/s PMD INTERFACE
— POWER AND GROUND PINS
— CLOCK INTERFACE
— SPECIAL CONNECT PINS
1.1 MII Interface
Signal Name Type
Pin #
Description
MDC
I
35
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 2.5 MHz. There is no minimum clock rate.
MDIO
I/O, Z 34
MANAGEMENT DATA I/O: Bi-directional management instruction/data signal that may
be sourced by the station management entity or the PHY. This pin requires a 1.5 kΩ pullup resistor.
CRS
I/O, Z 22
CARRIER SENSE: This pin is asserted high to indicate the presence of carrier due to
receive or transmit activities in 10BASE-T or 100BASE-X Half Duplex modes.
(SYMBOL)
In Repeater or Full Duplex mode, this pin is asserted high to indicate the presence of
carrier due only to receive activity.
In Symbol mode this pin indicates the signal detect status of the TP-PMD (active high).
COL
I/O, Z 21
(FXEN)
COLLISION DETECT: Asserted high to indicate detection of collision condition (assertion of CRS due to 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 (bit 7, register 18h), this
pin is also asserted for a duration of approximately 1 µs at the end of transmission to
indicate heartbeat (SQE test). During Repeater mode the heartbeat function is disabled.
In Full Duplex mode, for 10 Mb/s or 100 Mb/s operation, this signal is always logic 0.
There is no heartbeat function during 10 Mb/s full duplex operation.
TX_CLK
O, Z
33
TRANSMIT CLOCK: Transmit clock output from the DP83843:
25 MHz nibble transmit clock derived from Clock Generator Module's (CGM) PLL in
100BASE-TX mode.
2.5 MHz transmit clock in 10BASE-T Nibble mode.
10 MHz transmit clock in 10BASE-T Serial mode.
TXD[3]
I
28
TXD[2]
29
TXD[1]
30
TXD[0]
31
TX_EN
I
25
TRANSMIT DATA: Transmit data MII input pins that accept nibble data during normal
nibble-wide MII operation at either 2.5 MHz (10BASE-T mode) or 25 MHz (100BASE-X
mode).
In 10 Mb/s Serial mode, the TXD[0] pin is used as the serial data input pin, and TXD[3:1]
are ignored.
TRANSMIT ENABLE: Active high input indicates the presence of valid nibble data on
TXD[3:0] for both 100 Mb/s or 10 Mb/s nibble mode.
In 10 Mb/s Serial mode, active high indicates the presence of valid 10 Mb/s data on
TXD[0].
TX_ER
I
24
(TXD[4])
TRANSMIT ERROR: In 100 Mb/s mode, when this signal is high and TX_EN is active
the HALT symbol is substituted for the actual data nibble.
In 10 Mb/s mode, this input is ignored.
In Symbol mode (Symbol=0), TX_ER becomes the TXD [4] pin which is the MSB for the
transmit 5-bit data symbol.
RX_CLK
O, Z
18
RECEIVE CLOCK: Provides the recovered receive clock for different modes of operation:
25 MHz nibble clock in 100 Mb/s mode
2.5 MHz nibble clock in 10 Mb/s nibble mode
10 MHz receive clock in 10 Mb/s serial mode
5
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1.0 Pin Descriptions (Continued)
Signal Name Type
RXD[3]
O, Z
Pin #
12
RXD[2]
13
RXD[1]
14
RXD[0]
15
Description
RECEIVE DATA: Nibble wide receive data (synchronous to RX_CLK, 25 MHz for
100BASE-X mode, 2.5 MHz for 10BASE-T nibble mode). Data is driven on the falling
edge of RX_CLK.
In 10 Mb/s serial mode, the RXD[0] pin is used as the data output pin which is also
clocked out on the falling edge of RX_CLK. During 10 Mb/s serial mode RXD[3:1] pins
become don't cares.
RX_EN
I
23
RECEIVE ENABLE: Active high enable for receive signals RXD[3:0], RX_CLK, RX_DV
and RX_ER. A low on this input places these output pins in the TRI-STATE mode. For
normal operation in a node or switch application, this pin should be pulled high. For operation in a repeater application, this pin may be connected to a repeater controller.
RX_ER
O, Z
19
RECEIVE ERROR: Asserted high to indicate that an invalid symbol has been detected
within a received packet in 100 Mb/s mode.
(RXD[4])
In Symbol mode (Symbol = 0), RX_ER becomes RXD[4] which is the MSB for the receive 5-bit data symbol.
RX_DV
O, Z
20
RECEIVE DATA VALID: Asserted high to indicate that valid data is present on RXD[3:0]
for nibble mode and RXD[0] for serial mode. Data is driven on the falling edge of
RX_CLK.
This pin is not meaningful during Symbol mode.
1.2 10 Mb/s and 100 Mb/s PMD Interface
Signal Name
Type
Pin #
TPTD-
O
73
TPTD+
(MLT-3
74
Description
TRANSMIT DATA: Differential common output driver. This differential output
is configurable to either 10BASE-T or 100BASE-TX signaling:
10BASE-T: Transmission of Manchester encoded 10BASE-T packet data as
well as Link Pulses (including Fast Link Pulses for Auto-Negotiation purposes.)
or
10BASE-T)
100BASE-TX: Transmission of ANSI X3T12 compliant MLT-3 data.
The DP83843 will automatically configure this common output driver for the
proper signal type as a result of either forced configuration or Auto-Negotiation.
TPRD-
I
65
TPRD+
(MLT-3
67
RECEIVE DATA: Differential common input buffer. This differential input can
be configured to accept either 100BASE-TX or 10BASE-T signaling:
10BASE-T: Reception of Manchester encoded 10BASE-T packet data as well
as normal Link Pulses (including Fast Link Pulses for Auto-Negotiation purposes.)
or
10BASE-T)
100BASE-TX: Reception of ANSI X3T12 compliant scrambled MLT-3 data.
The DP83843 will automatically configure this common input buffer to accept
the proper signal type as a result of either forced configuration or Auto-Negotiation.
FXTD-/AUITD-
O
44
FXTD+/AUITD+
(PECL
43
or
AUI)
100BASE-FX or 10 Mb/s AUI TRANSMIT DATA: This configurable output
driver supports either 125 Mb/s PECL, for 100BASE-FX applications, or
10 Mb/s AUI signaling.
When configured as a 100BASE-FX transmitter this output sources
100BASE-FX standard compliant binary data for direct connection to an optical transceiver. This differential output is enabled only during 100BASE-FX
device configuration (see pin definition for FXEN.)
When configured as an AUI driver this output sources AUI compatible
Manchester encoded data to support typical 10BASE2 or 10BASE5 products.
6
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1.0 Pin Descriptions (Continued)
Signal Name
Type
Pin #
FXRD-/AUIRD-
I
49
FXRD+/AUIRD+
(PECL
50
or
Description
100BASE-FX or 10 Mb/s AUI RECEIVE DATA: This configurable input buffer supports either 125 Mb/s PECL, for 100BASE-FX applications, or 10 Mb/s
AUI signaling.
When configured as a 100BASE-FX receiver this input accepts 100BASE-FX
standard compliant binary data direct from an optical transceiver. This differential input is enabled only during 100BASE-FX device configuration (see the
pin definition for FXEN).
AUI)
When configured as an AUI buffer this input receives AUI compatible
Manchester data to support typical 10BASE2 or 10BASE5 products.
FXSD-/CD-
I
47
FXSD+/CD+
(PECL
48
or
SIGNAL DETECT or AUI COLLISION DETECT: This configurable input buffer supports either 125 Mb/s PECL, for 100BASE-FX applications, or 10 Mb/s
AUI signaling.
When configured as a 100BASE-FX receiver this input accepts indication
from the 100BASE-FX PMD transceiver upon detection of a receive signal
from the fiber media. This pin is only active during 100BASE-FX operation(see the pin definition for FXEN).
AUI)
When configured as an AUI buffer this input receives AUI compatible
Manchester data to support typical 10BASE2 or 10BASE5 products.
THIN
I/O, Z
63
THIN AUI MODE: This output allows for control of an external CTI coaxial
transceiver connected through the AUI. This pin is controlled by writing to bit
3 of the 10BTSCR register (address 18h). The THIN pin may also be used as
a user configurable output control pin.
I
(current
reference)
78
100 Mb/s TRANSMIT AMPLITUDE REFERENCE CONTROL: Reference
current allowing adjustment of the TPTD+/− output amplitude during
100BASE-TX operation.
(REPEATER)
TXAR100
By placing a resistor between this pin and ground or VCC, a reference current
is set up which dictates the output amplitude of the 100BASE-TX MLT-3
transmit signal. Connecting a resistor to VCC will increase the transmit amplitude while connecting a resistor to ground will decrease the transmit amplitude. While the value of the resistor should be evaluated on a case by case
bases, the DP83843 was designed to produce an amplitude close to the required range of 2V pk-pk differential ± 5% as measured across TD+/− while
driving a typical 100Ω differential load without a resistor connected to this pin.
Therefore this pin is allowed to float in typical applications.
This current reference is only recognized during 100BASE-TX operation and
has no effect during100BASE-FX,10BASE-T, or AUI modes of operation.
TWREF
I
60
TWISTER REFERENCE RESISTOR: External reference current adjustment,
via a resistor to TW_AGND, which controls the TP-PMD receiver equalization
levels. The value of this resistor is 70k ± 1%.
BGREF
I
(current
reference)
61
BANDGAP REFERENCE: External current reference resistor for internal
bandgap circuitry. The value of this resistor is 4.87k ± 1%.
VCM_CAP
I
66
COMMON MODE BYPASS CAPACITOR: External capacitor to improve
common mode filtering for the receive signal. It is recommended that a
.0033µF in parallel with a .10µF capacitor be used, see Figure 23.
7
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1.0 Pin Descriptions (Continued)
1.3 Clock Interface
Signal Name
Type
Pin #
Description
X1
I
9
CRYSTAL/OSCILLATOR INPUT: This pin is the primary clock reference input for
the DP83843 and must be connected to a 25 MHz 0.005% (50 ppm) clock source.
The DP83843 device supports either an external crystal resonator connected across
pins X1 and X2, or an external CMOS-level oscillator source connected to pin X1
only. For 100 Mb/s repeater applications, X1 should be tied to the common 25 MHz
transmit clock reference. Refer to section 4.4 for further detail relating to the clock
requirements of the DP83843. Refer to section 4.0 for clock source specifications.
X2
O
8
CRYSTAL/OSCILLATOR OUTPUT PIN: This pin is used in conjunction with the X1
pin to connect to an external 25 MHz crystal resonator device. This pin must be left
unconnected if an external CMOS oscillator clock source is utilized. For more information see the definition for pin X1. Refer to section 2.8 for further detail.
1.4 Device Configuration Interface
Signal Name
AN0
Type
I
Pin #
4
(3-level)
AN1
I
(3-level)
3
Description
AN0: This is a three level input pin (1, M, 0) that works in conjunction with the AN1
pin to control the forced or advertised operating mode of the DP83843 according to
the following table. The value on this pin is set by connecting the input pin to GND
(0), VCC (1), or leaving it unconnected (M.) The unconnected state, M, refers to the
mid-level (VCC/2) set by internal resistors. The value set at this input is latched into
the DP83843 at power-up/reset.
AN1
0
1
M
M
AN0
M
M
0
1
Forced Mode
10BASE-T, Half-Duplex without Auto-Negotiation
10BASE-T, Full Duplex without Auto-Negotiation
100BASE-X, Half-Duplex without Auto-Negotiation
100BASE-X, Full Duplex without Auto-Negotiation
AN1
M
AN0
M
0
0
0
1
1
0
1
1
Advertised Mode
All capable (i.e. Half-Duplex & Full Duplex for 10BASE-T and
100BASE-TX) advertised via Auto-Negotiation
10BASE-T, Half-Duplex & Full Duplex advertised via AutoNegotiation
100BASE-TX, Half-Duplex & Full Duplex advertised via
Auto-Negotiation
10BASE-T & 100BASE-TX, Half-Duplex advertised via AutoNegotiation
10 BASE-T, Half-Duplex advertised via Auto-Negotiation
AN1: This is a three-level input pin (i.e., 1, M, 0) that works in conjunction with the
AN0 pin to control the forced or advertised operating mode of the DP83843 according to the table given in the AN0 pin description above. The value on this pin is set
by connecting the input pin to GND (0), VCC (1), or leaving it unconnected (M.) The
value at this input is latched into the DP83843 at power-up, hardware or software
reset.
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1.0 Pin Descriptions (Continued)
Signal Name
REPEATER
Type
I/O
Pin #
63
(THIN)
Description
REPEATER/NODE MODE: Selects 100 Mb/s Repeater mode when set high and
node mode when set low. When set in Repeater mode the DP83843 only supports
100 Mb/s data rates. In Repeater mode (or Node mode with Full Duplex configured), the Carrier Sense (CRS) output from the DP83843 is asserted due to
receive activity only. In Half Duplex Node mode, CRS is asserted due to either
receive or transmit activity. During repeater mode the heartbeat function(SQE) is
forced off.
The Carrier Integrity Monitor (CIM) function is automatically enabled when this pin
is set high (repeater mode) and disabled when this pin is set low (node mode) in
order to facilitate 802.3u CIM requirements.
There is an internal pullup resistor for this pin which is active during the powerup/reset period. If this pin is left floating externally, then the device will configure to
100 Mb/s Repeater mode as a result of power-up/reset. This pin must be externally
pulled low (typically 10 kΩ) in order to configure the DP83843 for Node operation.
The value of this input is latched into the DP83843 at power-up, hardware or software reset.
SYMBOL/
I/O, Z
22
(CRS)
SYMBOL MODE: This active low input allows 100 Mb/s transmit and receive data
streams to bypass all of the transmit and receive operations when set low. Note
that the PCS signals (CRS, RX_DV, RX_ER, and COL) have no meaning during
this mode. During Symbol operation, pins RX_ER/RXD[4] and TX_ER/TXD[4] are
used as the MSB of the 5 bit RX and TX data symbols.
There is an internal pullup resistor for this pin which is active during the powerup/reset period. If this pin is left floating externally, then the device will configure to
normal mode as a result of power-up/reset. This pin must be externally pulled low
(typically 10 kΩ) in order to configure the DP83843 for Symbol mode operation.
In Symbol mode this pin will indicate the signal detect status of the TP-PMD (active
high).
This mode has no effect on 10Mb/s operation. The value at this input is latched into
the DP83843 at power-up, hardware or software reset.
SERIAL10
I
69
10BASE-T SERIAL/NIBBLE SELECT: With this active low input selected, transmit
and receive data are exchanged serially at a 10 MHz clock rate on the least significant bits of the nibble-wide MII data buses, pins TXD[0] and RXD[0] respectively.
This mode is intended for use with the DP83843 connected to a MAC using a 10
Mb/s serial interface. Serial operation is not supported in 100 Mb/s mode, therefore
this input is ignored during 100 Mb/s operation.
There is an internal pullup resistor for this pin which is active during the powerup/reset period. If this pin is left floating externally, then the device will configure to
normal mode as a result of power-up/reset. This pin must be externally pulled low
(typically 10 kΩ) in order to configure the DP83843 for Serial MII operation when
running at 10 Mb/s.
The value at this input is latched into the DP83843 at power-up, hardware or software reset.
FXEN/
(COL)
I/O, Z
21
FIBER ENABLE: This active low input allows 100 Mb/s transmit and receive data
streams to bypass the scrambler and descrambler circuits when selected. All PCS
signaling remains active and unaffected during this mode. During this mode, the
internal 100 Mb/s transceiver is disabled, and NRZI data is transmitted and
received via the FXTD/AUITD+/− and FXRD/AUIRD+/− pins.
There is an internal pullup resistor for this pin which is active during the powerup/reset period. If this pin is left floating externally, then the device will configure to
normal mode as a result of power-up/reset. This pin must be externally pulled low
(typically 10 kΩ) in order to configure the DP83843 for 100BASE-FX operation.
The value at this input is latched into the DP83843 at power-up, hardware or software reset.
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1.0 Pin Descriptions (Continued)
1.5 LED Interface
These outputs can be used to drive LEDs directly, or can
be used to provide status information to a network management device. Refer to section 2.2 for a description of
how to generate LED indication of 100 Mb/s mode. The
active state of each LED output driver is dependent on the
logic level sampled by the corresponding PHY address
input upon power-up/reset. For example, if a given PHYAD
Signal Name
LED_COL
Type
I/O
input is resistively pulled low then the corresponding LED
output will be configured as an active high driver. Conversely, if a given PHYAD input is resistively pulled high
then the corresponding LED output will be configured as an
active low driver (refer to section 5.0.1 for further details).
Note that these outputs are standard CMOS voltage
drivers and not open-drain.
Pin #
42
(PHYAD[0])
Description
COLLISION LED: Indicates the presence of collision activity for 10 Mb/s and 100
Mb/s Half Duplex operation. This LED has no meaning for 10 Mb/s or 100 Mb/s Full
Duplex operation and will remain deasserted. During 10 Mb/s half duplex mode this
pin will be asserted after data transmission due to the heartbeat function.
The DP83843 incorporates a “monostable” function on the LED_COL output. This
ensures that even collisions generate adequate LED ON time (approximately 50
ms) for visibility.
LED_TX
I/O
41
(PHYAD[1])
TRANSMIT LED: Indicates the presence of transmit activity for 10 Mb/s and 100
Mb/s operation.
If bit 7 (LED_Trans_MODE) of the PHYCTRL register (address 19h) is set high,
then the LED_TX pin function is changed to indicate the status of the Disconnect
function as defined by the state of bit 4 (CIM_STATUS) in the 100 Mb/s PCS configuration & status register (address 16h). See register definition for complete description of alternative operation.
The DP83843 incorporates a “monostable” function on the LED_TX output. This ensures that even minimum size packets generate adequate LED ON time (approximately 50 ms) for visibility.
LED_RX
I/O
40
(PHYAD[2])
RECEIVE LED: Indicates the presence of any receive activity for 10 Mb/s and 100
Mb/s operation. See register definitions(PHYCTRL register and PCSR register) for
complete descriptions of alternative operation.
The DP83843 incorporates a “monostable” function on the LED_RX output. This ensures that even minimum size packets generate adequate LED active time (approximately 50 ms) for visibility.
LED_LINK
I/O
39
(PHYAD[3])
LINK LED: Indicates good link status for 10 Mb/s and 100 Mb/s operation.
In 100BASE-T mode, link is established as a result of input receive amplitude compliant with TP-PMD specifications which will result in internal generation of Signal
Detect as well as an internal signal from the Clock Recovery Module (cypher &
sync). LED_LINK will assert after these internal signals have remained asserted for
a minimum of 500µs. Once Link is established, then cipher & sync are no longer
sampled and the Link will remain valid as long as Signal Detect is valid. LED_LINK
will deassert immediately following the deassertion of the internal Signal Detect.
10 Mb/s link is established as a result of the reception of at least seven consecutive
normal Link Pulses or the reception of a valid 10BASE-T packet which will cause
the assertion of LED_LINK. LED_LINK will deassert in accordance with the Link
Loss Timer as specified in IEEE 802.3.
In 100BASE-FX mode, link is established as a result of the assertion of the Signal
detect input to the DP83843. LED_LINK will assert after Signal Detect has remained
asserted for a minimum of 500µS. LED_LINK will deassert immediately following
the deassertion of signal detect.
The link function is disabled during AUI operation and LED_LINK is asserted.
LED_FDPOL
I/O
38
(PHYAD[4])
FULL DUPLEX LED: Indicates Full Duplex mode status for 10 Mb/s or 100 Mb/s
operation. This pin can be configured to indicate Polarity status for 10 Mb/s operation. If bit 6 (LED_DUP_MODE) in the PHYCTRL Register (address 19h) is deasserted, the LED_FDPOL pin function is changed to indicate Polarity status for 10
Mb/s operation.
The DP83843 automatically compensates for 10BASE-T polarity inversion.
10BASE-T polarity inversion is indicated by the assertion of LED_FDPOL.
SPEED10
O
5
SPEED 10 Mb/s: Indicates 10 Mb/s operation when high. Indicates 100 Mb/s operation when low. This pin can be used to drive peripheral circuitry such as an LED
indicator.
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1.0 Pin Descriptions (Continued)
1.6 PHY Address Interface
The DP83843 PHYAD[4:0] inputs provide up to 32 unique
PHY address options. An address selection of all zeros
Signal Name
Type
PHYAD[0]
(00000) will result in a PHY isolation condition as a
result of power-on/reset, as specified in IEEE 802.3u.
Pin #
I/O
42
(LED_COL)
Description
PHY ADDRESS [0]: PHY address sensing pin for multiple PHY applications. PHY
address sensing is achieved by strapping a pull-up/pull-down resistor (typically 10
kΩ) to this pin as required.
The pull-up/pull-down status of this pin is latched into the PHYCTRL register (address 19h, bit 0) during power up/reset.
PHYAD[1]
I/O
41
(LED_TX)
PHY ADDRESS [1]: PHY address sensing pin for multiple PHY applications. PHY
address sensing is achieved by strapping a pull-up/pull-down resistor (typically 10
kΩ) to this pin as required.
The pull-up/pull-down status of this pin is latched into the PHYCTRL register (address 19h, bit 1) during power up/reset.
I/O
PHYAD[2]
40
(LED_RX)
PHY ADDRESS [2]: PHY address sensing pin for multiple PHY applications. PHY
address sensing is achieved by strapping a pull-up/pull-down resistor (typically 10
kΩ) to this pin as required.
The pull-up/pull-down status of this pin is latched into the PHYCTRL register (address 19h, bit 2) during power up/reset.
PHYAD[3]
I/O
39
(LED_LINK)
PHY ADDRESS [3]: PHY address sensing pin for multiple PHY applications. PHY
address sensing is achieved by strapping a pull-up/pull-down resistor (typically 10
kΩ) to this pin as required.
The pull-up/pull-down status of this pin is latched into the PHYCTRL register (address 19h, bit 3) during power up/reset.
PHYAD[4]
I/O
38
(LED_FDPOL)
PHY ADDRESS [4]: PHY address sensing pin for multiple PHY applications. PHY
address sensing is achieved by strapping a pull-up/pull-down resistor (typically 10
kΩ) to this pin as required.
The pull-up/pull-down status of this pin is latched into the PHYCTRL register (address 19h, bit 4) during power up/reset.
1.7 Reset
Signal Name
RESET
Type
I
Pin #
1
Description
RESET: Active high input that initializes or reinitializes the DP83843. Asserting this
pin will force a reset process to occur which will result in all internal registers reinitializing to their default states as specified for each bit in section 7.0, and all strapping options are reinitialized. Refer to section 5.0 for further detail regarding reset.
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1.0 Pin Descriptions (Continued)
1.8 Power And Ground Pins
The power (VCC) and ground (GND) pins of the DP83843
are grouped in pairs into three categories--TTL/CMOS
Input pairs, Transmit/Receive supply pairs, and Internal
Signal Name
supply pairs. This grouping allows for optimizing the layout
and filtering of the power and ground supplies to this
device.
Pin #
Description
TTL/CMOS INPUT/OUTPUT SUPPLY PAIRS
IO_VDD1
6
IO_VSS1
7
TTL Input/Output Supply #1
IO_VDD2
16
IO_VSS2
17
IO_VDD3
26
IO_VSS3
27
IO_VSS4
32
TTL Input/Output Supply #4
IO_VDD5
36
TTL Input/ Output Supply #5
IO_VSS5
37
PCS_VDD
10
PCS_VSS
11
TTL Input/Output Supply #2
TTL Input /Output Supply #3
Physical Coding Sublayer Supply
TRANSMIT/RECEIVE SUPPLY PAIRS
AUIFX_VDD
46
AUIFX_GND
45
TR_AVDD
79
TR_AGND
80
TW_AVDD
68
TW_AGND
64
CD_VDD0
72
CD_GND0
71
CD_VDD1
76
CD_GND1
75
AUI Power Supply
10 Mb/s Supply
100 Mb/s Power Supply
Common Driver Supply
Common Driver Supply
INTERNAL SUPPLY PAIRS
CP_AVDD
52
CP_AGND
51
CPTW_DVDD
54
CPTW_DVSS
53
CRM/CGM Supply
CRM/CGM Supply
ATP_GND
57
100BASE-T PMD Supply
SUB_GND1,
70
100BASE-T PMD Supply
SUB_GND2
77
1.9 Special Connect Pins
Signal Name
NC
Type
Pin #
2,55,56,
58,59,
62
Description
NO CONNECT: These pins are reserved for future use. Leave them unconnected
(floating).
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2.0 Functional Description
2.1 802.3u MII
The DP83843 incorporates the Media Independent Interface (MII) as specified in clause 22 of the IEEE 802.3u
standard. This interface may be used to connect PHY
devices to a 10/100 Mb/s MAC or a 100 Mb/s repeater controller. This section describes both the serial MII management interface as well as the nibble wide MII data interface.
The management interface of the MII allows the configuration and control of multiple PHY devices, the gathering of
status and error information, and the determination of the
type and abilities of the attached PHY(s).
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
or repeater).
and no minimum rate. The MDIO line is bi-directional and
may be shared by up to 32 devices. The MDIO frame format is shown in Table 1.
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 (SME) sends a sequence of 32 contiguous logic
ones on MDIO to provide the DP83843 with a sequence
that can be used to establish synchronization. This preamble may be generated either by driving MDIO high for 32
consecutive MDC clock cycles, or by simply allowing the
MDIO pull-up resistor to pull the MDIO pin high during
which time 32 MDC clock cycles are provided. In addition
32 MDC clock cycles should be used if an invalid start, op
code, or turnaround bit is detected.
The DP83843 waits until it has received this preamble
The DP83843 supports the TI ThunderLAN® MII interrupt sequence before responding to any other transaction.
function. For further information please contact your local Once the DP83843 serial management port has initialized
National sales representative.
no further preamble sequencing is required until after a
power-on/reset has occurred.
2.1.1 Serial Management Register Access
The serial MII specification defines a set of thirty-two 16-bit
status and control registers that are accessible through the
serial management data interface pins MDC and MDIO.
The DP83843 implements all the required MII registers as
well as several optional registers. These registers are fully
described in Section 7. A description of the serial management access protocol follows.
The Start code is indicated by a <01> pattern. This assures
the MDIO line transitions from the default idle line state.
Turnaround is an idle bit time inserted between the Register Address field and the Data field. To avoid contention, no
device actively drives the MDIO signal during the first bit of
Turnaround during a read transaction. The addressed
DP83843 drives the MDIO with a zero for the second bit of
turnaround and follows this with the required data. Figure 2
2.1.2 Serial Management Access Protocol
shows the timing relationship between MDC and the MDIO
The serial control interface consists of two pins, Manage- as driven/received by the Station Management Entity and
ment Data Clock (MDC) and Management Data Input/Out- the DP83843 (PHY) for a typical register read access.
put (MDIO). MDC has a maximum clock rate of 2.5 MHz
Table 1. Typical MDIO Frame Format
MII Management
Serial Protocol
<idle><start><op code><device addr> <reg addr><turnaround><data><idle>
Read Operation
<idle><01><10><AAAAA> <RRRRR><Z0><xxxx xxxx xxxx xxxx><idle>
Write Operation
<idle><01><01><AAAAA> <RRRRR><10><xxxx xxxx xxxx xxxx><idle>
MDC
MDIO
Z
Z
(SME)
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
Z
Idle
Start
Opcode
(Write)
PHY Address
(PHYAD = 0Ch)
Register Address
(00h = BMCR)
Register Data
TA
Z
Idle
Figure 1. Typical MDC/MDIO Write Operation
MDC
MDIO
Z
Z
(SME)
Z
MDIO
Z
(PHY)
Z
Idle
0 1 1 0 0 1 1 0 0 0 0 0 0 0Z 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0
Start
Opcode
(Read)
PHY Address
(PHYAD = 0Ch)
Register Address
(00h = BMCR)
TA
Register Data
Z
Idle
Figure 2. Typical MDC/MDIO Read Operation
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2.0 Functional Description (Continued)
For write transactions, the Station Management Entity
writes data to an addressed DP83843 eliminating the
requirement for MDIO Turnaround. The Turnaround time is
filled by the management entity inserting <10> for these
two bits. Figure 1 shows the timing relationship for a typical
MII register write access.
2.1.3 Preamble Suppression
The DP83843 supports a Preamble Suppression mode as
indicated by a one in bit 6 of the Basic Mode Status Register (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.
The DP83843 requires a single initialization sequence of
32 bits of preamble following power-up/hardware reset.
This 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 Preamble Suppression is supported.
While the DP83843 requires an initial preamble sequence
of 32 bits for management initialization, it does not require
a full 32 bit sequence between each subsequent transaction. A minimum of one idle bit between management
transactions is required as specified in IEEE 802.3u.
2.1.4 PHY Address Sensing
The DP83843 can be set to respond to any of the possible
32 PHY addresses. Each DP83843 connected to a common serial MII must have a unique address. It should be
noted that while an address selection of all zeros <00000>
will result in PHY Isolate mode, this will not effect serial
management access.
occur during half-duplex operation when both a transmit
and receive operation occur simultaneously.
2.1.6 Collision Detect
For Half Duplex, a 10BASE-T or 100BASE-X collision is
detected when the receive and transmit channels are
active simultaneously. Collisions are reported by the COL
signal on the MII.
If the DP83843 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 duration of the collision.
If a collision occurs during a receive operation, it is immediately reported by the COL signal.
When heartbeat is enabled (only applicable to 10 Mb/s
operation), approximately 1 µs after the transmission of
each packet, a Signal Quality Error (SQE) signal of approximately 10 bit times is generated (internally) to indicate
successful transmission. SQE is reported as a pulse on the
COL signal of the MII.
2.1.7 Carrier Sense
Carrier Sense (CRS) may be asserted due to receive activity, once valid data is detected via the Smart Squelch function during 10 Mb/s operation.
For 10 Mb/s Half Duplex operation, CRS is asserted during
either packet transmission or reception.
For 10 Mb/s Full Duplex operation, CRS is asserted only
due to receive activity.
CRS is deasserted following an end of packet.
In Repeater mode (pin 63/bit 9, register address 19h), CRS
The DP83843 provides five PHY address pins, the state of is only asserted due to receive activity.
which are latched into the PHYCTRL register (address 2.1.8 MII Isolate Mode
19h) at system power-up/reset. These pins are described
A 100BASE-X PHY connected to the mechanical MII interin Section 2.8. For further detail relating to the latch-in timface specified in IEEE 802.3u is required to have a default
ing requirements of the PHY address pins, as well as the
value of one in bit 10 of the Basic Mode Control Register
other hardware configuration pins, refer to Section 3.10.
(BMCR, address 00h). The DP83843 will set this bit to one
2.1.5 Nibble-wide MII Data Interface
if the PHY Address is set to 00000 upon power-up/hardClause 22 of the IEEE 802.3u specification defines the ware reset. Otherwise, the DP83843 will set this bit to zero
Media Independent Interface. This interface includes a upon power-up/hardware reset.
dedicated receive bus and a dedicated transmit bus. These
two data buses, along with various control and indicate signals, allow for the simultaneous exchange of data between
the DP83843 and the upper layer agent (MAC or repeater).
With bit 10 in the BMCR set to one, the DP83843 does not
respond to packet data present at TXD[3:0], TX_EN, and
TX_ER inputs and presents a high impedance on the
TX_CLK, RX_CLK, RX_DV, RX_ER, RXD[3:0], COL, and
The receive interface consists of a nibble wide data bus CRS outputs. The DP83843 will continue to respond to all
RXD[3:0], a receive error signal RX_ER, a receive data serial management transactions over the MII.
valid flag RX_DV, and a receive clock RX_CLK for synchro- While in Isolate mode, the TPTD+/− and FXTD/AUITD+/−
nous transfer of the data. The receive clock can operate at outputs are dependent on the current state of Auto-Negotieither 2.5 MHz to support 10 Mb/s operation modes or at ation. The DP83843 can Auto-Negotiate or parallel detect
25 MHz to support 100 Mb/s operational modes.
to a specific technology depending on the receive signal at
The transmit interface consists of a nibble wide data bus the TPRD+/− inputs. A valid link can be established for
TXD[3:0], a transmit error flag TX_ER, a transmit enable either TPRD or FXRD/AUI even when the DP83843 is in
control signal TX_EN, and a transmit clock TX_CLK which Isolate mode.
runs at either 2.5 MHz or 25 MHz.
It is recommended that the user have a basic understandAdditionally, the MII includes the carrier sense signal CRS, ing of clause 22 of the 802.3u standard.
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
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2.0 Functional Description (Continued)
2.2 100BASE-TX TRANSMITTER
The 100BASE-TX transmitter consists of several functional
blocks which convert synchronous 4-bit nibble data, as provided by the MII, to a scrambled MLT-3 125 Mb/s serial data
stream. Because the 100BASE-TX TP-PMD is integrated,
the differential output pins, TPTD+/−, can be directly routed
to the AC coupling magnetics.
The block diagram in Figure 3 provides an overview of
each functional block within the 100BASE-TX transmit section.
— Code-group Encoder and Injection block (bypass option)
— Scrambler block (bypass option)
— NRZ to NRZI encoder block
— Binary to MLT-3 converter / Common Driver
The bypass option for the functional blocks within the
100BASE-X transmitter provides flexibility for applications
such as 100 Mb/s repeaters where data conversion is not
always required. The DP83843 implements the 100BASEX transmit state machine diagram as specified in the IEEE
802.3u Standard, Clause 24.
The Transmitter section consists of the following functional
blocks:
TX_CLK
TXD[3:0] /
TX_ER
25MHZ
CODE-GROUP
ENCODER &
INJECTOR
BP_4B5B
MUX
SCRAMBLER
BP_SCR
BP_TX
MUX
MUX
PARALLEL
TO SERIAL
NRZ TO NRZI
ENCODER
100BASE-X
LOOPBACK
BINARY
TO MLT-3 /
COMMON
DRIVER
TPTD +/−
Figure 1. 100BASE-TX Transmit Block Diagram
– Code-group Encoding and Injection
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2.0 Functional Description (Continued)
The code-group encoder converts 4 bit (4B) nibble data
generated by the MAC into 5 bit (5B) code-groups for transmission. This conversion is required to allow control data to
be combined with packet data code-groups. Refer to Table
2 for 4B to 5B code-group mapping details.
2.2.1 Scrambler
The scrambler is required to control the radiated emissions
at the media connector and on the twisted pair cable (for
100BASE-TX applications). By scrambling the data, the
total energy launched onto the cable is randomly distribThe code-group encoder substitutes the first 8 bits of the uted over a wide frequency range. Without the scrambler,
MAC preamble with a J/K code-group pair (11000 10001) energy levels at the PMD and on the cable could peak
upon transmit. The code-group encoder continues to beyond FCC limitations at frequencies related to repeating
replace subsequent 4B preamble and data nibbles with 5B sequences (i.e., continuous transmission of IDLEs).
corresponding 5B code-groups. At the end of the transmit The scrambler is configured as a closed loop linear feedpacket, upon the deassertion of Transmit Enable signal back shift register (LFSR) with an 11-bit polynomial. The
from the MAC or Repeater, the code-group encoder injects output of the closed loop LFSR is combined with the NRZ
the T/R code-group pair (01101 00111) indicating the end 5B data from the code-group encoder via an X-OR logic
of frame.
function. The result is a scrambled data stream with suffiAfter the T/R code-group pair, the code-group encoder
continuously injects IDLEs into the transmit data stream
until the next transmit packet is detected (reassertion of
Transmit Enable).
cient randomization to decrease radiated emissions at certain frequencies by as much as 20 dB. The DP83843 uses
the PHYID as determined by the PHYAD [4:0] pins to set a
unique seed value for the scrambler so that the total energy
The DP83843 also incorporates a special injection function produced by a multi-PHY application (i.e. repeater) distribwhich allows for fixed transmission of special repeating pat- utes the energy out of phase across the spectrum and
terns for testing purposes. These special patterns are not helps to reduce overall electro-magnetic radiation.
delimited with Start of Stream Delimiter (SSD) or End of The scrambler is automatically bypassed when the
Stream Delimiter (ESD) code-groups and should not be DP83843 is placed in FXEN mode via hardware or, alternaenabled during normal network connectivity.
tively, controlled by bit 12 of LBR (address 17h) via softThese patterns, selectable via bits [8:7] of PCRS (address ware.
16h), include:
2.2.2 NRZ to NRZI Encoder
8=0, 7=0: Normal operation (injection disabled)
After the transmit data stream has been scrambled and
serialized, the data must be NRZI encoded in order to com8=0, 7=1: Transmit repeating FEFI pattern
ply with the TP-PMD standard for 100BASE-TX transmis8=1, 7=0: Transmit repeating 1.28 µs period squarewave
sion over Category-5 unshielded twisted pair cable. There
is no ability to bypass this block within the DP83843.
8=1, 7=1: Transmit repeating 160 ns period squarewave
Note that these patterns will be routed through the transmit
scrambler and become scrambled (and therefore potentially less useful) unless the scrambler is bypassed via bit
12 of LBR (address 17h). It should be noted that if the
scrambler is bypassed by forcing the FXEN pin (and subsequently resetting the device) the TPTD+/− outputs will
become disabled and the test pattern data will be routed to
the FXTD/AUITD+/− outputs. Additionally, the test patterns
will not be generated if the DP83843 is in symbol mode.
2.2.3 Binary to MLT-3 Convertor / Common Driver
The Binary to MLT-3 conversion is accomplished by converting the serial binary datastream 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
these streams to current sources and alternately drives
either side of the transmit transformer primary winding
resulting in a minimal current (20 mA max) MLT-3 signal.
Refer to Figure 4 .
binary_in
binary_plus
Q
D
Q
binary_minus
differential MLT-3
CP
binary_plus
binary_in
COMMON
DRIVER
MLT-3
binary_minus
Figure 1. Binary to MLT-3 conversion
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2.0 Functional Description (Continued)
Table 2. 4B5B Code-Group Encoding/Decoding
Name
PCS 5B Code-group
MII 4B Nibble Code
0
11110
0000
1
01001
0001
2
10100
0010
3
10101
0011
4
01010
0100
5
01011
0101
6
01110
0110
7
01111
0111
8
10010
1000
9
10011
1001
A
10110
1010
DATA CODES
B
10111
1011
C
11010
1100
D
11011
1101
E
11100
1110
F
11101
1111
IDLE AND CONTROL CODES
H
00100
Halt code-group - Error code
I
11111
Inter-Packet Idle - 0000 (Note 1)
J
11000
First Start of Packet - 0101 (Note 1)
K
10001
Second Start of Packet - 0101 (Note 1)
T
01101
First End of Packet - 0000 (Note 1)
R
00111
Second End of Packet - 0000 (Note 1)
V
00000
0110 or 0101 (Note 2)
V
00001
0110 or 0101 (Note 2)
V
00010
0110 or 0101 (Note 2)
V
00011
0110 or 0101 (Note 2)
V
00101
0110 or 0101 (Note 2)
V
00110
0110 or 0101 (Note 2)
V
01000
0110 or 0101 (Note 2)
V
01100
0110 or 0101 (Note 2)
V
10000
0110 or 0101 (Note 2)
V
11001
0110 or 0101 (Note 2)
INVALID CODES
Note 1: Control code-groups I, J, K, T and R in data fields will be mapped as invalid codes, together with RX_ER asserted.
Note 2: Normally, invalid codes (V) are mapped to 6h on RXD[3:0] with RX_ER asserted. If the CODE_ERR bit in the PCS (bit 3, register address 16h)
is set, the invalid codes are mapped to 5h on RXD[3:0] with RX_ER asserted. Refer to Section 4.14 for further detail.
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2.0 Functional Description (Continued)
The 100BASE-TX MLT-3 signal sourced by the TPTD+/−
common driver output pins is slow rate controlled. This
should be considered when selecting AC coupling magnetics to ensure TP-PMD compliant transition times (3 ns < Tr
< 5ns).
The 100BASE-TX transmit TP-PMD function within the
DP83843 is capable of sourcing only MLT-3 encoded data.
Binary output from the TPTD+/− outputs is not possible in
100 Mb/s mode.
2.2.4 TX_ER
Assertion of the TX_ER input while the TX_EN input is also
asserted will cause the DP83843 to substitute HALT codegroups for the 5B data present at TXD[3:0]. However, the
SSD (/J/K/) and ESD (/T/R/) will not be substituted with
Halt code-groups. As a result, the assertion of TX_ER
while TX_EN is asserted will result in a frame properly
encapsulated with the /J/K/ and /T/R/ delimiters which contains HALT code-groups in place of the data code-groups.
such as 100 Mb/s repeaters where data conversion is not
always required.
2.3.1 Input and Base Line Wander Compensation
Unlike the DP83223V TWISTER™, the DP83843 requires
no external attenuation circuitry at its receive inputs,
TPRD+/−. The DP83843 accepts TP-PMD compliant waveforms directly, requiring only a 100Ω termination plus a
simple 1:1 transformer. The DP83843 also requires external capacitance to VCC at the VCM_CAP pin (refer to Figure 23). This establishes a solid common mode voltage
that is needed since the TPRD pins are used in both 10
Mb/s and 100 Mb/s modes.
The DP83843 is completely ANSI TP-PMD compliant
because it compensates for baseline wander. The BLW
compensation block can successfully recover the TP-PMD
defined “killer” pattern and pass it to the digital adaptive
equalization block.
Baseline wander can generally be defined as the change in
the average DC content, over time, of an AC coupled digital
transmission over a given transmission medium. (i.e. copThe transmit amplitude of the signal presented at the
per wire).
TPTD+/− output pins can be controlled by varying the value
of resistance between TXAR100 and system GND. This Baseline wander results from the interaction between the
TXAR100 resistor sets up a reference current that deter- low frequency components of a bit stream being transmitted and the frequency response of the AC coupling compomines the final output current at TPTD+/−.
nent(s) within the transmission system. If the low frequency
For 100Ω Category-5 UTP cable implementations, the
content of the digital bit stream goes below the low freTXAR100 resistor may be omitted as the DP83843 was
quency pole of the AC coupling transformers then the
designed to source a nominal 2V pk-pk differential transmit
droop characteristics of the transformers will dominate
amplitude with this pin left floating. Setting the transmit
resulting in potentially serious baseline wander.
amplitude to 2V pk-pk differential (MLT-3) as measured
across the RJ45-8 transmit pins is critical for complying It is interesting to note that the probability of a baseline wanwith the IEEE/ANSI TP-PMD specification of 2.0V pk-pk der event serious enough to corrupt data is very low. In fact,
it is reasonable to virtually bound the occurrence of a basedifferential ± 5%.
line wander event serious enough to cause bit errors to a
2.3 100BASE-TX RECEIVER
legal but premeditated, artificially constructed bit sequence
The 100BASE-TX receiver consists of several functional loaded into the original MAC frame. Several studies have
blocks which convert the scrambled MLT-3 125 Mb/s serial been conducted to evaluate the probability of various basedata stream to synchronous 4-bit nibble data that is pro- line wander events for FDDI transmission over copper. Convided to the MII. Because the 100BASE-TX TP-PMD is tact the X3.263 ANSI group for further information.
integrated, the differential input pins, TPRD+/−, can be 2.3.2 Signal Detect
directly routed to the AC coupling magnetics.
The signal detect function of the DP83843 is incorporated
See Figure 5 for a block diagram of the 100BASE-TX
to meet the specifications mandated by the ANSI FDDI TPreceive function. This provides an overview of each funcPMD Standard as well as the IEEE 802.3 100BASE-TX
tional block within the 100BASE-TX receive section.
Standard for both voltage thresholds and timing parameThe Receive section consists of the following functional ters.
blocks:
Note that the reception of Normal 10BASE-T link pulses
— Input and BLW Compensation
and fast link pulses per IEEE 802.3u Auto-Negotiation by
the 100BASE-X receiver do not cause the DP83843 to
— Signal Detect
assert signal detect.
— Digital Adaptive Equalization
While signal detect is normally generated and processed
— MLT-3 to Binary Decoder
entirely within the DP83843, it can be observed directly on
— Clock Recovery Module
the CRS pin (pin 22) while the DP83843 is configured for
Symbol mode. Refer to Section 3.4 for further detail regard— NRZI to NRZ Decoder
ing Symbol mode operation.
— Serial to Parallel
2.3.3 Digital Adaptive Equalization
— DESCRAMBLER (bypass option)
When transmitting data at high speeds over copper twisted
— Code Group Alignment
pair cable, frequency dependent attenuation becomes a
— 4B/5B Decoder (bypass option)
concern. In high speed twisted pair signalling, the fre— Link Integrity Monitor
quency content of the transmitted signal can vary greatly
— Bad SSD Detection
during normal operation based primarily on the randomThe bypass option for the functional blocks within the ness of the scrambled data stream. This variation in signal
100BASE-X receiver provides flexibility for applications
2.2.5 TXAR100
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2.0 Functional Description (Continued)
RX_CLK
RXD[3:0] / RX_ER
BP_RX
MUX
BP_4B5B
MUX
CARRIER
INTEGRITY
MONITOR
SD
4B/5B
DECODER
LINK INTEGRITY MONITOR
CODE GROUP
ALIGNMENT
RX_DATA
VALID SSD
DETECT
MUX
BP_SCR
DESCRAMBLER
SERIAL TO
PARALLEL
CLOCK
DATA
NRZI TO NRZ
DECODER
CLOCK
RECOVERY
MODULE
MLT-3 TO
BINARY
DECODER
DIGITAL
ADAPTIVE
EQUALIZATION
INPUT
&BLW
COMPENSATION
SIGNAL
DETECT
TPRD +/−
Figure 1. Receive Block Diagram
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2.0 Functional Description (Continued)
attenuation caused by frequency variations must be compensated for to ensure the integrity of the transmission.
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 compensation which will over-compensate for shorter, less attenuating lengths. Conversely, the selection of short or
intermediate cable lengths requiring less compensation will
cause serious under-compensation for longer length
cables. Therefore, the compensation or equalization must
be adaptive to ensure proper conditioning of the received
signal independent of the cable length.
tenuation (dB)
The DP83843 utilizes an extremely robust equalization
scheme referred to herein as ‘Digital Adaptive Equalization.’ Existing designs use an adaptive equalization scheme
that determines the approximate cable length by monitoring signal attenuation at certain frequencies. This attenuation value was compared to the internal receive input
reference voltage. This comparison would indicate that
amount of equalization to use. Although this scheme is
used successfully on the DP83223V TWISTER, it is sensitive to transformer mismatch, resistor variation and process
induced offset. The DP83223V also required an external
attenuation network to help match the incoming signal
amplitude to the internal reference.
100M
22.00
50M
0M
20.00
18.00
16.00
14.00
12.00
10.00
8.00
6.00
4.00
Figure 1. EIA/TIA Attenuation vs Frequency for 0, 50,
100 meters of CAT-5 cable
Digital Adaptive Equalization is based on an advanced digitally controlled signal tracking technique. This method
uses peak tracking with digital over-sampling and digitally
controlled feedback loops to regenerate the receive signal.
This technique does not depend on input amplitude variations to set the equalization factor. As a result it maintains
constant jitter performance for any cable length up to 150
meters of CAT-5. Digital Adaptive Equalization allows for
very high tolerance to signal amplitude variations.
The curves given in Figure 6 illustrate attenuation at certain
frequencies for given cable lengths. This is derived from the
worst case frequency vs. attenuation figures as specified 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 circuit.
Figure 7 represents a scrambled IDLE transmitted over
zero meters of cable as measured at the AII (Active Input
2ns/div
Interface) of the receiver. Figure 8 and Figure 9 represent
the signal degradation over 50 and 100 Meters of CAT-5 Figure 2. MLT-3 Signal Measured at AII after 0 meters of
cable respectively, also measured at the AII. These plots
CAT-5 cable
show the extreme degradation of signal integrity and indicate the requirement for a robust adaptive equalizer.
2.3.5 Clock Recovery Module
The DP83843 provides the added flexibility of controlling The Clock Recovery Module (CRM) accepts 125 Mb/s
the type of receive equalization required for a given imple- NRZI data from the MLT-3 to NRZI decoder. The CRM locks
mentation. This is done through TW_EQSEL (bits [13:12] onto the 125 Mb/s data stream and extracts a 125 MHz refof the PHYCTRL register, address 19h). While digital adap- erence clock. The extracted and synchronized clock and
tive equalization is the preferred method of cable compen- data are used as required by the synchronous receive
sation for 100BASE-TX, the ability to switch the equalizer operations as generally depicted in Figure 5.
completely off or to a fixed maximum is provided. This feaThe CRM is implemented using an advanced digital Phase
ture is intended as a test mode only and, if enabled, will
Locked Loop (PLL) architecture that replaces sensitive
inhibit normal performance of the DP83843.
analog circuits. Using digital PLL circuitry allows the
2.3.4 MLT-3 to NRZI Decoder
DP83843 to be manufactured and specified to tighter tolerThe DP83843 decodes the MLT-3 information from the Dig- ances.
ital Adaptive Equalizer block to binary NRZI data. The rela- For further information relating to the 100BASE-X clock
tionship of binary to MLT-3 data is shown in Figure 4.
recovery module, refer to Section 4.3.
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2.0 Functional Description (Continued)
required function for ultimately providing data to the nibblewide interface of the MII.
2.3.8 Descrambler
A 5-bit parallel (code-group wide) descrambler is used to
descramble the receive NRZ data. To reverse the data
scrambling process, the descrambler has to generate an
identical data scrambling sequence (N) in order to recover
the original unscrambled data (UD) from the scrambled
data (SD) as represented in the equations:
SD = ( UD ⊕ N )
UD = ( SD ⊕ N )
Synchronization of the descrambler to the original scrambling sequence (N) is achieved based on the knowledge
that the incoming scrambled data stream consists of
scrambled IDLE data. After the descrambler has recognized 12 consecutive IDLE code-groups, where an 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.
2ns/div
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 synchronization status. Upon synchronization of the descrambler the
hold timer starts a 722 µs countdown. Upon detection of
sufficient IDLE code-groups within the 722 µs period, the
hold timer will reset and begin a new countdown. 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 current state
of synchronization and reset in order to re-acquire synchronization.
Figure 1. MLT-3 Signal Measured at AII after 50 meters
of CAT-5 cable
The value of the time-out for this timer may be modified
from 722 sto 2 ms by setting bit 12 of the PCSR (address
16h) to one. The 2 ms option allows applications with Maximum Transmission Units (packet sizes) larger than IEEE
802.3 specifications to maintain descrambler synchronization (i.e. switch or router applications).
Additionally, this timer may be disabled entirely by setting
bit 11 of the PCSR (address 16h) to one. The disabling of
the time-out timer is not recommended as this will eventually result in a lack of synchronization between the transmit
scrambler and the receive descrambler which will corrupt
data. The descrambler time-out counter may be reset by bit
13 of the PCSR.
2ns/div
Figure 2. MLT-3 Signal Measured at AII after 100 meters
of CAT-5 cable
2.3.6 NRZI to NRZ
In a typical application, the NRZI to NRZ
required in order to present NRZ formatted
descrambler (or to the code-group alignment
descrambler is bypassed, or directly to the
receiver is bypassed).
2.3.9 Code-group Alignment
decoder is
data to the
block, if the
PCS, if the
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 converts it into 5B code-group data (5 bits). Code-group alignment occurs after the J/K code-group pair is detected.
The receive data stream is in NRZI format, therefore, the data Once the J/K code-group pair (11000 10001) is detected,
subsequent data is aligned on a fixed boundary.
must be decoded to NRZ before further processing.
2.3.10 4B/5B Decoder
2.3.7 Serial to Parallel
The 100BASE-X receiver includes a Serial to Parallel converter which supplies 5 bit wide data symbols to the
Descrambler. Converting to parallel helps to decrease
latency through the device, as well as performing the
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
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2.0 Functional Description (Continued)
the MAC preamble. Specifically, the J/K 10-bit code-group
pair is replaced by the nibble pair (0101 0101). All subsequent 5B code-groups are converted to the corresponding
4B nibbles for the duration of the entire packet. This conversion 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.
Detection of an unstable link condition will cause bit 4 of
the PCS register (address 16h) to be set to one. This bit is
cleared to zero upon a read operation once a stable link
condition is detected by the CIM. Upon detection of a stable link, the DP83843 will resume normal operations.
2.3.11 100BASE-X Link Integrity Monitor
2.4 10BASE-T TRANSCEIVER MODULE
The Disconnect Counter (address 13h) increments each
time the CIM determines that the link is unstable.
The 100BASE-X Link Integrity Monitor function (LIM)
allows the receiver to ensure that reliable data is being
received. Without reliable data reception, the LIM will halt
both transmit and receive operations until such time that a
valid link is detected (i.e. good link).
The 10BASE-T Transceiver Module is IEEE 802.3 compliant. It includes the receiver, transmitter, collision, heartbeat, 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
If Auto-Negotiation is not enabled, then a valid link will be DP83843. Due to the complexity and scope of the
indicated once SD+/− is asserted continuously for 500 µs.
10BASE-T Transceiver block and various sub-blocks, this
If Auto-Negotiation is enabled, then Auto-Negotiation will section focuses on the general system level operation.
further qualify a valid link as follows:
2.4.1 Operational Modes
— The descrambler must receive a minimum of 12 IDLE
The DP83843 has 2 basic 10BASE-T operational modes:
code groups for proper link initialization.
Half Duplex mode
— The Auto-Negotiation must determine that the
Full Duplex mode
100BASE-X function should be enabled.
A valid link for a non-Auto-Negotiating application is indi- Half Duplex Mode
cated by either the Link LED output or by reading bit 2 of In Half Duplex mode the DP83843 functions as a standard
the Basic Mode Status Register BMSR (address 01h). For IEEE 802.3 10BASE-T transceiver supporting the
a truly qualified valid link indication as a result of Auto- CSMA/CD protocol.
Negotiation, bit 2 of the BMSR register (address 01h) must
Full Duplex Mode
be read.
In Full Duplex mode the DP83843 is capable of simulta2.3.12 Bad SSD Detection
neously transmitting and receiving without asserting the
A Bad Start of Stream Delimiter (Bad SSD) is any transition collision signal. The DP83843's 10 Mb/s ENDEC is
from consecutive idle code-groups to non-idle code-groups designed to encode and decode simultaneously.
which is not prefixed by the code-group pair /J/K.
2.4.2 Oscillator Module Operation
If this condition is detected, the DP83843 will assert
A 25 MHz crystal or can-oscillator with the following specifiRX_ER and present RXD[3:0] = 1110 to the MII for the
cations is recommended for driving the X1 input.
cycles that correspond to received 5B code-groups. In
order to exit this state the PHYTER must receive at least 1. CMOS output with a 50ppm frequency tolerance.
two IDLE code groups and the PHYTER cannot receive a 2. 35-65% duty cycle (max).
single IDLE code group at any time. In addition, the False
3. Two TTL load output drive.
Carrier Event Counter (address 14h) will be incremented
by one. Once the PHYTER exits this state, RX_ER and Additional output drive may be necessary if the oscillator
must also drive other components. When using a clock
CRS become de-asserted.
oscillator it is still recommended that the designer connect
When bit 11 of the LBR register is one (BP_RX), RXD[3:0] the oscillator output to the X1 pin and leave X2 floating.
and RX_ER/RXD[4] are not modified.
2.4.3 Smart Squelch
2.3.13 Carrier Integrity Monitor
The smart squelch is responsible for determining when
The Carrier Integrity Monitor function (CIM) protects the valid data is present on the differential receive inputs
repeater from transient conditions that would otherwise (TPRD+/−). The DP83843 implements an intelligent
cause spurious transmission due to a faulty link. This func- receive squelch to ensure that impulse noise on the receive
tion is required for repeater applications and is not speci- inputs will not be mistaken for a valid signal. Smart squelch
fied for node applications.
operation is independent of the 10BASE-T operational
The REPEATER pin (pin 63) determines the default state of mode.
bit 5 of the PCS register (Carrier Integrity Monitor Disable, The squelch circuitry employs a combination of amplitude
address 16h) to automatically enable or disable the CIM and timing measurements (as specified in the IEEE 802.3
function as required for IEEE 802.3 compliant applications. 10BASE-T standard) to determine the validity of data on
After power-up/reset, software may enable or disable this the twisted pair inputs (refer to Figure 10).
function independent of Repeater or Node mode.
The signal at the start of packet is checked by the smart
If the CIM determines that the link is unstable, the squelch and any pulses not exceeding the squelch level
DP83843 will not propagate the received data or control (either positive or negative, depending upon polarity) will
signaling to the MII and will ignore data transmitted via the be rejected. Once this first squelch level is overcome corMII. The DP83843 will continue to monitor the receive rectly, the opposite squelch level must then be exceeded
stream for valid carrier events.
within 150 ns. Finally the signal must exceed the original
squelch level within a further 150 ns to ensure that the
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2.0 Functional Description (Continued)
Twisted Pair Squelch Operation
<150ns <150ns
>150ns
Vsq +
Vsq +
reduced
Vsq reduced
Vsq start of packet
end of packet
Figure 1. 10BASE-T Twisted Pair Smart Squelch Operation
input waveform will not be rejected. The checking proce- 2.4.5 Normal Link Pulse Detection/Generation
dure results in the loss of typically three preamble bits at
The link pulse generator produces pulses as defined in the
the beginning of each packet.
IEEE 802.3 10BASE-T standard. Each link pulse is nomiOnly after all these conditions have been satisfied will a nally 100 ns in duration and is transmitted every 16 ms ± 8
control signal be generated to indicate to the remainder of ms, in the absence of transmit data.
the circuitry that valid data is present. At this time, the Link pulse is used to check the integrity of the connection
smart squelch circuitry is reset.
with the remote end. If valid link pulses are not received,
Valid data is considered to be present until squelch level
has not been generated for a time longer than 150ns, 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 link detector disables the 10BASE-T twisted pair transmitter, receiver and collision detection functions.
When the link integrity function is disabled, the 10BASE-T
transceiver will operate regardless of the presence of link
pulses.
The receive squelch threshold level can be lowered for use 2.4.6 Jabber Function
in longer cable applications. This is achieved by setting the
LS_SEL bit in the 10BTSCR (bit 6, register 18h). Collision The jabber function monitors the DP83843's output and
disables the transmitter if it attempts to transmit a packet of
Detection
longer than legal size. A jabber timer monitors the transmitFor Half Duplex, a 10BASE-T collision is detected when the
ter and disables the transmission if the transmitter is active
receive and transmit channels are active simultaneously.
for approximately 20-30 ms.
Collisions are reported by the COL signal on the MII.
Once disabled by the Jabber function, the transmitter stays
If the ENDEC is transmitting when a collision is detected,
disabled for the entire time that the ENDEC module's interthe collision is not reported until seven bits have been
nal transmit enable is asserted. This signal has to be dereceived while in the collision state. This prevents a colliasserted for approximately 400-600 ms (the “unjab” time)
sion being reported incorrectly due to noise on the network.
before the Jabber function re-enables the transmit outputs.
The COL signal remains set for the duration of the collision.
If the ENDEC is receiving when a collision is detected it is The Jabber function is only meaningful in 10BASE-T mode.
reported immediately (through the COL).
2.4.7 Status Information
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 (internally) to indicate successful transmission. SQE is reported
as a pulse on the COL signal of the MII.
2.4.4 Carrier Sense
Carrier Sense (CRS) may be asserted due to receive activity once valid data is detected via the smart squelch function.
For 10 Mb/s Half Duplex operation, CRS is asserted during
either packet transmission or reception.
10BASE-T Status Information is available on the LED output pins of the DP83843. Transmit activity, receive activity,
link status, link polarity and collision activity information is
output to the five LED output pins (LED_RX, LED_TX,
LED_LINK, LED_FDPOL, and LED_COL). Additionally, the
active high SPEED10 output will assert to indicate 10 Mb/s
operation.
If required, the LED outputs can be used to provide digital
status information to external circuitry.
The link LED output indicates good link status for both 10
and 100 Mb/s modes. In Half Duplex 10BASE-T mode,
LED_LINK indicates link status.
For 10 Mb/s Full Duplex operation, CRS is asserted only
The link integrity function can be disabled. When disabled,
due to receive activity.
the transceiver will operate regardless of the presence of
CRS is deasserted following an end of packet.
link pulses and the link LED will stay asserted continuously.
In Repeater mode, CRS is only asserted due to receive
2.4.8 Automatic Link Polarity Detection
activity.
The DP83843's 10BASE-T transceiver module incorporates an automatic link polarity detection circuit. When
seven consecutive link pulses or three consecutive receive
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2.0 Functional Description (Continued)
packets with inverted End-of-Packet pulses are received, 2.4.12 Manchester Encoder
bad polarity is reported.
The encoder begins operation when the Transmit Enable
A polarity reversal can be caused by a wiring error at either input (TX_EN) goes high and converts the NRZ data to
end of the cable, usually at the Main Distribution Frame pre-emphasized Manchester data for the transceiver. For
(MDF) or patch panel in the wiring closet.
the duration of TX_EN remaining high, the Transmit Data
The bad polarity condition is latched and the LED_ FDPOL (TPTD+/−) is encoded for the transmit-driver pair
output is asserted. The DP83843's 10BASE-T transceiver (TPTD+/−). TXD must be valid on the rising edge of Transmodule corrects for this error internally and will continue to mit Clock (TX_CLK). Transmission ends when TX_EN
decode received data correctly. This eliminates the need to 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
correct the wiring error immediately.
of the bit cell if the last bit is a zero.
2.4.9 10BASE-T Internal Loopback
2.4.13 Manchester Decoder
When the 10MB_ENDEC_LB bit in the LBR (bit 4, register
address 17h) is set, 10BASE-T transmit data is looped The decoder consists of a differential receiver and a PLL to
back in the ENDEC to the receive channel. The transmit separate a Manchester encoded data stream into internal
drivers and receive input circuitry are disabled in trans- clock signals and data. The differential input must be exterceiver loopback mode, isolating the transceiver from the nally terminated with either a differential 100ohm termination network to accommodate UTP cable.
network.
Loopback is used for diagnostic testing of the data path The decoder detects the end of a frame when no more midthrough the transceiver without transmitting on the network bit transitions are detected. Within one and a half bit times
or being interrupted by receive traffic. This loopback func- after the last bit, carrier sense is de-asserted. Receive
tion causes the data to loopback just prior to the 10BASE-T clock stays active for five more bit times after CRS goes
output driver buffers such that the entire transceiver path is low, to guarantee the receive timings of the controller or
repeater.
tested.
2.4.10 Transmit and Receive Filtering
2.5 100 BASE-FX
External 10BASE-T filters are not required when using the The DP83843 is fully capable of supporting 100BASE-FX
DP83843 as the required signal conditioning is integrated. applications. 100BASE-FX is similar to 100BASE-TX with
the exceptions being the PMD sublayer, lack of data scramOnly isolation/step-up transformers and impedance match- bling, and signaling medium and connectors. Chapter 26 of
ing resistors are required for the 10BASE-T transmit and the IEEE 802.3u specification defines the interface to this
receive interface. The internal transmit filtering ensures PMD sublayer.
that all the harmonics in the transmit signal are attenuated
The DP83843 can be configured for 100BASE-FX operaby at least 30 dB.
tion either through hardware or software. Configuration
2.4.11 Encoder/Decoder (ENDEC) Module
through hardware is accomplished by forcing the FXEN pin
The ENDEC module consists of essentially four functions: (pin 21) to a logic low level prior to power-up/reset. Configuration through software is accomplished by setting bits 9:7
The oscillator generates the 10 MHz transmit clock signal
of the LBR register to <011>, enabling FEFI (bit 14 of regisfor system timing from an external 25 MHz oscillator.
ter PCSR(16h)), bypassing the scrambler (bit 12 of register
The Manchester encoder accepts NRZ data from the con- LBR(17h)) and disabling Auto-Negotiation. In addition, settroller or repeater, encodes the data to Manchester, and ting the FX_EN bit of the PHYCTRL register (bit 5, address
transmits it differentially to the transceiver, through the dif- 19h) accomplishes the same function as forcing the FXEN
ferential transmit driver.
pin (pin 21) to a logic low. In 100BASE-FX mode, the FX
The Manchester decoder receives Manchester data from interface is enabled along with the Far End Fault Indication
the transceiver, converts it to NRZ data and recovers clock (FEFI) and Bypass Scrambler functions. Auto-Negotiation
pulses for synchronous data transfer to the controller or must be disabled in order for 100BASE-FX operation to
work properly.
repeater.
The collision monitor indicates to the controller the pres- The diagram in Figure 11 is a block diagram representation
of the FX interface and the alternative data paths for transence of a valid 10 Mb/s collision signal.
mit, receive and signal detect.
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2.0 Functional Description (Continued)
NORMAL RX DATA TO
DESCRAMBLER BYPASS
NORMAL TX DATA
W/ SCRAMBLER BYPASSED
NORMAL
SIGNAL DETECT
CLOCK
RECOVERY
MODULE
NRZ TO NRZI
ENCODER
PECL
INPUTS
PECL
DRIVER
SIGNAL
DETECT
INPUT &BLW COMP
BINARY
TO MLT-3 /
COMMON
DRIVER
FULL ADAPT. EQUALIZ.
MLT-3 TO BINARY DEC.
TPTD+/−
FXTD
FXRD
FXSD
TPRD+/−
Figure 1. 100Base-FX Block Diagram
tiation is not currently specified for operation over fiber, the
Far End Fault Indication function (FEFI) provides some
When the FX interface is enabled the internal 100BASE-TX
degree of communication between link partners in support
transceiver is disabled. As defined by the 802.3u specificaof 100BASE-FX operation.
tion, PMD_SIGNAL_indicate (signal detect function),
PMD_UNITDATA.indicate
(receive
function),
and A remote fault is an error in the link that one station can
PMD_UNIT_DATA.request (transmit function) are sup- detect while the other cannot. An example of this is a disported by the FXSD+/−, FXRD+/−, and FXTD+/− pins connected fiber at a station’s transmitter. This station will
be receiving valid data and detect that the link is good via
respectively.
the Link Integrity Monitor, but will not be able to detect that
Transmit
its transmission is not propagating to the other station.
The DP83843 transmits NRZI data on the FXTD+/− pins.
A 100BASE-FX station that detects such a remote fault
This data is transmitted at PECL signal levels. 100BASE(through the deassertion of signal detect) may modify its
FX requires no scrambling/de-scrambling, so the scrambler
transmitted IDLE stream from all ones to a group of 84
is bypassed in the transmit path. All other PMA and PCS
ones followed by a single zero (i.e. 16 IDLE code groups
functions remain unaffected.
followed by a single Data 0 code group). This is referred to
Receive
as the FEFI IDLE pattern. Transmission of the FEFI IDLE
The DP83843 receives NRZI data on the FXRD+/− pins. pattern will continue until FXSD+/− is re-asserted.
2.5.1 FX Interface
This data is accepted at PECL signal levels. 100BASE-FX
requires no scrambling/de-scrambling, so the de-scrambler
is bypassed in the receive path. All other PMA and PCS
functions remain unaffected.
If three or more FEFI IDLE patterns are detected by the
DP83843, then bit 4 of the Basic Mode Status register
(address 01h) is set to one until read by management. It is
also set in bit 7 of the PHY Status register (address 10h).
Signal Detect
The first FEFI IDLE pattern may contain more than 84 ones
The DP83843 receives signal detect information on the as the pattern may have started during a normal IDLE
FXSD+/− pins. This data is accepted at PECL signal levels. transmission which is actually quite likely. However, since
Signal detect indicates that a signal with the proper ampli- FEFI is a repeating pattern, this will not cause a problem
with the FEFI function. It should be noted receipt of the
tude is present at the PMD sublayer.
FEFI IDLE pattern will not cause CRS to assert.
2.5.2 Far End Fault Indication
To enable Fiber mode without FEFI, set bits 9:7 of the LBR
Auto-Negotiation provides a mechanism for transferring register to <011>, disable FEFI (bit 14 of register
information from the Local Station to the Link Partner that a PCSR(16h)), bypass the scrambler (bit 12 of register
remote fault has occurred for 100BASE-TX. As Auto-Nego-
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2.0 Functional Description (Continued)
LBR(17h)) and disable Auto-Negotiation. Without FEFI This function is optional for 100BASE-FX compliance and
enabled the DP83843 will not send the FEFI idle pattern.
should be disabled for 100BASE-TX compliance. If AutoAdditionally, upon detection of Far End Fault, all receive Negotiation is enabled (bit 12 of the BMCR) then FEFI is
and transmit MII activity is disabled/ignored (MII serial automatically disabled. FEFI is automatically enabled when
the DP83843 is configured for 100BASE-FX operation.
management is unaffected).
VCC
DP83843 100BASE-FX
82Ω
90Ω
130Ω
82Ω
82Ω
90Ω
9-pin Optical Transceiver
50
FXRD+/- 49
RX_DATA+/-
FXSD+/- 48
47
Signal_Detect +
RX
TX
FXTD+/- 43
44
TX_DATA+/370Ω
130Ω
130Ω
115Ω
130Ω
115Ω
PECL Thevenin Termination
Figure 1. Typical DP83843 to Optical Transceiver Interfaces
2.5.3 Software Enable
The FX functions can also be set via software. The FXinterface is set by bit 5 of the PHYCTRL register (address
19h). The FEFI_EN function is set by bit 14 of register 16h.
The bypass scrambler and de-scrambler function is set by
bit 11 of the loopback and bypass register (address 17h).
AUI mode is selected by bit 5 (AUI_SEL) of the 10BASE-T
Control and Status register (10BTSCR). It can also be activated by the Autoswitch feature explained below.
Autoswitch overrides the AUI_SEL bit. The Status of the
port, either AUI or TP mode, is displayed in bit 12
(AUI_TPI) of the 10BTSCR register.
2.5.4 FX Interface Considerations
2.6.1 AUI Block Diagram
The termination and signal routing for the high-speed The pins at the AUI interface are AUIRD+/−, AUITD+/−, and
PECL signals are critical. The following diagram shows a AUICD+/−. They provide the Read, Transmit and Collision
Detect functions respectively. See Figure 13 for a block diatypical thevenin termination circuit.
gram of the AUI interface. The AUI interface includes the
Chapter 26 of the 802.3u 100BASE-X document includes
MII Interface/Control
references to the three most common types of 125 Mb/s
optical transceiver connectors available. The DP83843 may
be used with any of these three connectors.
tx_data
tx_clk
crs rx_clk
col_
It is important to note that the typical 9-pin low cost fiber
detect
rx_data
transceiver utilizes a single-ended PECL output for Signal
Detect indication. Since the DP83843 incorporates stanManchester
PLL
dard differential PECL inputs for Signal Detect, the FXSDCollision
Encoder
Decoder
input (pin 47) can be externally biased as depicted in
Decoder
& Driver
Figure 12 to ensure proper operation.
Optionally, the proper bias potential for FXSD- can be generated by the DP83843 internally. This is accomplished by
AUICD+/AUIRD+/AUITD+/setting bit 15 of register 16 (PCSR). This option eliminates
the requirement for additional external passive components
which would otherwise be required for the proper biasing of
Figure 1. AUI Block Diagram
FXSD- in an application where only a single-ended SD signal is available.
PLL Decoder, Collision Decoder and Manchester Encoder
and Driver.
2.6 AUI
The DP83843 is capable of operating in 10BASE-2 and
10BASE-5 applications. This is done by utilizing the AUI
(Attachment Unit Interface) pins of the DP83843. The AUI
interface is completely IEEE 802.3 compliant. See
Figure 14 for an example of a typical AUI connector setup.
The PLL Decoder receives Manchester data from the
transceiver, converts it to NRZ data and clock pulses and
sends it to the controller.
The collision decoder indicates to the MII the presence of a
valid 10 MHz collision signal to the PLL.
26
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2.0 Functional Description (Continued)
The Manchester encoder accepts NRZ data from the MII,
encodes the data to Manchester and sends it to the driver.
The driver transmits the data differentially to the transceiver.
2.6.2 AUI/TP Autoswitch
The DP83843 has an autoswitching feature that allows
switching between the AUI and TP operation. The AUI/TPI
autoswitch feature (AUTOSW_EN) is enabled by bit 9 of
the 10BASE-T Control and Status Register (10BTSCR). If
AUTOSW_EN is asserted (default is de-asserted) and the
DP83843 is in 10 Mb/s mode it automatically activates the
TPI interface (10 Mb/s data is transmitted and received at
the TPTD+/− and TPRD+/− pins respectively). If there is an
absence of link pulses, the transceiver will switch to AUI
mode. Similarly, when the transceiver starts detecting link
pulses it will switch to TP mode. The switching from one
mode to the next is only done after the current packet has
been transmitted or received. If the twisted pair output is
jabbering and gets into link fail state, then the switch to AUI
mode is only done after the jabbering is done, including the
time it takes to unjab (unjab time).
2.6.3 Ethernet Cable Configuration / THIN Output
The DP83843 offers the choice of Thick Ethernet
(10BASE5) and Thin Ethernet (10BASE-2). The type of
cabling used is controlled through bit 3 of the 10BTSCR
register (address 18h). The DP83843 also provides a THIN
output signal which can be used to disable/enable an external DC-DC converter which is required for 10BASE-2 applications to provide electrical isolation. This enables a
10BASE-2 and10BASE-5 common interface application.
AUITD
200Ω
AUIRD
AUICD
200Ω
100uH
39Ω
39Ω
39Ω
.01uf
39Ω
.01uf
15 Pin D AUI Connector
Figure 1. AUI Typical Setup
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3.0 Configuration
This section includes information on the various configura- Figure 15). These pins allow configuration options to be
tion options available with the DP83843. The configuration selected without requiring internal register access.
options described herein include:
It should be noted that due to the internal resistor networks
depicted in Figure 15, the AN0 or AN1 should be con— Auto-Negotiation
nected directly to either VCC or GND, depending on the
— PHY Address and LEDs
requirements. These pins should never be resistively tied to
— Half Duplex vs Full Duplex
VCC or GND as this will interfere with the internal pull-up
— 100M Symbol mode
and pull-down resistors resulting in improper Auto-Negotiation behavior.
— 100BASE-FX mode
The state of AN0 and AN1, upon power-up/reset, deter— 10M serial MII mode
mines the state of bit 9 in the PHYSTS register (address
— 10M AUI Mode
10h) as well as bits [8:5] of the ANAR register (address
— Repeater vs. Node
04h).
— Isolate mode
Upon power-up/reset the DP83843 uses default register
— Loopback mode
values, which enables Auto-Negotiation and advertises the
full set of abilities (10 Mb/s Half Duplex, 10 Mb/s Full
3.1 Auto-Negotiation
Duplex, 100 Mb/s Half Duplex, and 100 Mb/s Full Duplex)
The Auto-Negotiation function provides a mechanism for unless subsequent software accesses modify the mode.
exchanging configuration information between two ends of
a link segment and automatically selecting the highest per- The status of Auto-Negotiation as a function of hardware
formance mode of operation supported by both devices. configuration via the AN0 and AN1 pins is reflected in bit 9
Fast Link Pulse (FLP) Bursts provide the signaling used to of the PHYSTS register (address 10h).
communicate Auto-Negotiation abilities between two The Auto-Negotiation function selected at power-up or
devices at each end of a link segment. For further detail reset can be changed at any time by writing to the Basic
regarding Auto-Negotiation, refer to clause 28 of the IEEE Mode Control Register (BMCR) at address 00h.
802.3u specification. The DP83843 supports four different 3.1.2 Auto-Negotiation Register Control
Ethernet protocols (10 Mb/s Half Duplex, 10 Mb/s Full
Duplex, 100 Mb/s Half Duplex, and 100 Mb/s Full Duplex), When Auto-Negotiation is enabled, the DP83843 transmits
so the inclusion of Auto-Negotiation ensures that the high- the abilities programmed into the Auto-Negotiation Adverest performance protocol will be selected based on the tisement register (ANAR) at address 04h via FLP Bursts.
ability of the Link Partner. The Auto-Negotiation function Any combination of 10 Mb/s, 100 Mb/s, Half-Duplex, and
within the DP83843 can be controlled either by internal Full Duplex modes may be selected. The default setting of
register access or by use of the AN1 and AN0 (pins 3 & 4). bits [8:5] in the ANAR and bit 9 in the PHYSTS register
(address 10h) are determined at power-up or hard reset by
3.1.1 Auto-Negotiation Pin Control
the state of the AN0 and AN1 pins.
The state of AN0 and AN1 determines whether the The BMCR provides software with a mechanism to control
DP83843 is forced into a specific mode or Auto-Negotiation the operation of the DP83843. However, the AN0 and AN1
will advertise a specific ability (or set of abilities) as given in pins do not affect the contents of the BMCR and cannot be
Table 3. Pins AN0 and AN1 are implemented as three-level used by software to obtain status of the mode selected.Bits
control pins which are configured by connecting them to 1 & 2 of the PHYSTS register (address 10h) are only valid
VCC, GND, or by leaving them unconnected (refer to if Auto-Negotiation is disabled or after Auto-Negotiation is
complete.
VH
R
A
+
VIN
R
B
DECODER
VCC
OUT
VIN
A
B
OUT
0V
L
L
L
VCC /2
L
H
M
VCC
H
H
H
+
VL
GND
Figure 15. 3 Level Hardware Configuration Pin Control
The contents of the ANLPAR register are used to automatically configure to the highest performance protocol
between the local and far-end ports. Software can determine which mode has been configured by Auto-Negotiation
by comparing the contents of the ANAR and ANLPAR registers and then selecting the technology whose bit is set in
both the ANAR and ANLPAR of highest priority relative to
the following list.
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3.0 Configuration (Continued)
Table 3. Auto-Negotiation Mode Select
AN1
(Pin 3)
AN0
(Pin 4)
Action
Mode
FORCED MODES
0
M
PHYSTS (10h) Bit 9 = 0, Bit 1 = 1, Bit 2 = 0
10BASE-T, Half-Duplex without Auto-Negotiation
ANAR (04h) [8:0] = 021h
1
M
PHYSTS (10h) Bit 9 = 0, Bit 1 = 1, Bit 2 = 1
10BASE-T, Full Duplex without Auto-Negotiation
ANAR (04h) [8:0] = 041h
M
0
M
1
PHYSTS (10h) Bit 9 = 0, Bit 1 = 0, Bit 2 = 0
ANAR (04h) [8:0] = 081h
PHYSTS (10h) Bit 9 = 0, Bit1 = 0, Bit 2 = 1
ANAR (04h) [8:0] = 101h
100BASE-X, Half-Duplex without Auto-Negotiation
100BASE-X, Full Duplex without Auto-Negotiation
ADVERTISED MODES
M
M
PHYSTS (10h) Bit 9 = 1
All capable (i.e. Half-Duplex & Full Duplex for
10BASE-T and 100BASE-TX) advertised via
Auto-Negotiation
ANAR (04h) [8:0] = 1E1h
0
0
0
1
PHYSTS (10h) Bit 9 = 1
10BASE-T, Half-Duplex & Full Duplex advertised
via Auto-Negotiation
ANAR (04h) [8:0] = 061h
PHYSTS (10h) Bit 9 = 1
100BASE-TX, Half-Duplex & Full Duplex advertised via Auto-Negotiation
ANAR (04h) [8:0] = 181h
1
0
PHYSTS (10h) Bit 9 = 1
10BASE-T & 100BASE-TX, Half-Duplex advertised via Auto-Negotiation
ANAR (04h) [8:0] = 0A1h
1
1
PHYSTS (10h) Bit 9 = 1
10 BASE-T, Half-Duplex advertised via Auto-Negotiation.
ANAR (04h) [8:0] = 021h
Note: “M” indicates logic mid level (Vcc/2), “1” indicates logic high level, “0” indicates logic low level.
Auto-Negotiation Priority Resolution:
— Whether the Link Partner is advertising that a remote
fault has occurred (bit 4, register address 01h)
— Whether a valid link has been established (bit 2, register
address 01h)
— Support for Management Frame Preamble suppression
(bit 6, register address 01h)
The Auto-Negotiation Advertisement Register (ANAR) at
address 04h indicates the Auto-Negotiation abilities to be
advertised by the DP83843. All available abilities are transmitted by default, but any ability can be suppressed by writing to the ANAR. Updating the ANAR to suppress an ability
is one way for a management agent to change (force) the
technology that is used.
— (1) 100BASE-TX Full Duplex (Highest Priority)
— (2) 100BASE-TX Half Duplex
— (3) 10BASE-T Full Duplex
— (4) 10BASE-T Half Duplex (Lowest Priority)
The Basic Mode Control Register (BMCR) at address 00h
provides control of enabling, disabling, and restarting of the
Auto-Negotiation function. When Auto-Negotiation is disabled the Speed Selection bit in the BMCR (bit 13, register
address 00h) controls switching between 10 Mb/s or 100
Mb/s operation, while the Duplex Mode bit (bit 8, register
address 00h) controls switching between full duplex operation and half duplex operation. The Speed Selection and
Duplex Mode bits have no effect on the mode of operation The Auto-Negotiation Link Partner Ability Register
when the Auto-Negotiation Enable bit (bit 12, register (ANLPAR)at address 05h is used to receive the base link
code word as well as all next page code words during the
address 00h) is set.
negotiation. Furthermore, the ANLPAR will be updated to
The Basic Mode Status Register (BMSR) at address 01h either 0081h or 0021h for parallel detection to either 100
indicates the set of available abilities for technology types Mb/s or 10 Mb/s respectively.
(bits 15 to 11, register address 01h), Auto-Negotiation ability (bit 3, register address 01h), and Extended Register If Next Page is NOT being used, then the ANLPAR will
Capability (bit 0, register address 01h). These bits are per- store the base link code word (link partner's abilities) and
manently set to indicate the full functionality of the retain this information from the time the page is received,
DP83843 (only the 100BASE-T4 bit is not set since the as indicated by a 1 in bit 1 of the Auto-Negotiation ExpanDP83843 does not support that function, while it does sup- sion Register (ANER, register address 06h), through the
end of the negotiation and beyond.
port all the other functions).
When using the next page operation, the DP83843 cannot
The BMSR also provides status on:
wait for Auto-Negotiation to complete in order to read the
— Whether Auto-Negotiation is complete (bit 5, register ad- ANLPAR because the register is used to store both the
dress 01h)
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3.0 Configuration (Continued)
base and next pages. Software must be available to perform several functions. The ANER (register 6) must have a
page received (bit 1), once the DP83843 receives the first
page, software must store it in memory if it wants to keep
the information. Auto-Negotiation keeps a copy of the base
page information but it is no longer accessible by software.
After reading the base page information, software needs to
write to ANNPTR (register 7) to load the next page information to be sent. Continue to poll the page received bit in the
ANER and when active read the ANLPAR. The contents of
the ANLPAR will tell if the partner has further pages to be
sent. As long as the partner has more pages to send, software must write to the next page transmit register and load
another page.
ner. 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 determine that
negotiation completed via Parallel Detection by reading a
zero in the Link Partner Auto-Negotiation Able bit (bit 0,
register address 06h) once the Auto-Negotiation Complete
bit (bit 5, register address 01h) is set. If configured for parallel detect mode and any condition other than a single
good link occurs then the parallel detect fault bit will set (bit
4, register 06h).
3.1.4 Auto-Negotiation Restart
Once Auto-Negotiation has completed, it may be restarted
at any time by setting bit 9 of the BMCR to one. If the mode
configured by a successful Auto-Negotiation loses a valid
The Auto-Negotiation Expansion Register (ANER) at link, then the Auto-Negotiation process will resume and
address 06h indicates additional Auto-Negotiation status. attempt to determine the configuration for the link. This
The ANER provides status on:
function ensures that a valid configuration is maintained if
— Whether a Parallel Detect Fault has occurred (bit 4, reg- the cable becomes disconnected.
ister address 06h)
A renegotiation request from any entity, such as a manage— Whether the Link Partner supports the Next Page func- ment agent, will cause the DP83843 to halt any transmit
tion (bit 3, register address 06h)
data and link pulse activity until the break_link_timer
— Whether the DP83843 supports the Next Page function expires (~1500ms). Consequently, the Link Partner will go
(bit 2, register address 06h). The DP83843 does support into link fail and normal Auto-Negotiation resumes. The
DP83843 will resume Auto-Negotiation after the
the Next Page function.
break_link_timer has expired by issuing FLP (Fast Link
— Whether the current page being exchanged by Auto-NePulse) bursts.
gotiation has been received (bit1, register address 06h)
— Whether the Link Partner supports Auto-Negotiation (bit 3.1.5 Enabling Auto-Negotiation via Software
0, register address 06h)
It is important to note that if the DP83843 has been initialThe Auto-Negotiation Next Page Transmit Register ized upon power-up as a non-auto-negotiating device
(ANNPTR) at address 07h contains the next page code (forced technology), and it is then required that Auto-Negoword to be sent. See Table 13 for a bit description of this tiation or re-Auto-Negotiation be initiated via software, bit
12 of the Basic Mode Control Register (address 00h) must
register.
first be cleared and then set for any Auto-Negotiation func3.1.3 Auto-Negotiation Parallel Detection
tion to take effect.
The DP83843 supports the Parallel Detection function as 3.1.6 Auto-Negotiation Complete Time
defined in the IEEE 802.3u specification. Parallel Detection
requires both the 10 Mb/s and 100 Mb/s receivers to moni- Parallel detection and Auto-Negotiation take approximately
tor the receive signal and report link status to the Auto- 2-3 seconds to complete. In addition, Auto-Negotiation with
Negotiation function. Auto-Negotiation uses this informa- next page should take approximately 2-3 seconds to comtion to configure the correct technology in the event that the plete, depending on the number of next pages sent.
Link Partner does not support Auto-Negotiation yet is Refer to chapter 28 of the IEEE 802.3u standard for a full
transmitting link signals that the 100BASE-X or 10BASE-T description of the individual timers related to Auto-NegotiaPMAs recognize as valid link signals.
tion.
The Auto-Negotiation function will only accept a valid link Auto-Negotiation Next Page Support
signal for the purpose of Parallel Detection from PMAs
which have a corresponding bit set in the Auto-Negotiation The DP83843 supports the optional Auto-Negotiation Next
Advertisement register, (ANAR register bits 5 and 7, Page protocol. The ANNPTR register (address 07h) allows
address 04h.) This allows the DP83843 to be configured for the configuration and transmission of Next Page. Refer
for 100 Mb/s only, 10 Mb/s only, or 10 Mb/s & 100 Mb/s to clause 28 of the IEEE 802.3u standard for detailed inforCSMA/CD operation depending on the advertised abilities. mation regarding the Auto-Negotiation Next Page function.
The state of these bits may be modified via the AN0 and 3.2 PHY Address and LEDs
AN1 pins or by writing to the ANAR. For example, if bit 5 is
zero, and bit 7 is one in the ANAR (i.e. 100 Mb/s CSMA/CD The DP83843 maps the 5 PHY address input pins onto the
only), and the Link Partner is 10BASE-T without Auto- 5 LED output pins as:
LED_COL <=> PHYAD[0]
Negotiation, then Auto-Negotiation will not complete since
the advertised abilities and the detected abilities have no
LED_TX <=> PHYAD[1]
common mode. This operation allows the DP83843 to be
LED_RX <=> PHYAD[2]
used in single mode (i.e. repeater) applications as well as
LED_LINK <=> PHYAD[3]
dual mode applications (i.e. 10/100 nodes or switches).
LED_FDPOL <=> PHYAD[4]
If the DP83843 completes Auto-Negotiation as a result of
Parallel Detection, without Next Page operation, bits 5 and The DP83843 can be set to respond to any of 32 possible
7 within the ANLPAR register (register address 05h) will be PHY addresses. Each DP83843 connected to a common
set to reflect the mode of operation present in the Link Part- serial MII must have a unique address. It should be noted
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3.0 Configuration (Continued)
that while an address selection of all zeros <00000> will The adaptive nature of the LED outputs helps to simplify
result in PHY Isolate mode, this will not effect serial man- potential implementation issues of these dual purpose
pins.
agement access.
Refer to the PHYCTRL register (address 19h) bits [8:6] for
further information regarding LED operations and configuration.
Since the PHYAD strap options share the LED output pins,
the external components required for strapping and LED
usage must be considered in order to avoid contention.
Additionally, the sensing and auto polarity feature of the
LED must be taken into account.
Half-duplex is the standard, traditional mode of operation
which relies on the CSMA/CD protocol to handle collisions
and network access. In Half-Duplex mode, CRS responds
to both transmit and receive activity in order to maintain
compliant to the IEEE 802.3 specification.
Specifically, these LED outputs can be used to drive LEDs
directly, or can be used to provide status information to a
network management device. The active state of each LED
output driver is dependent on the logic level sampled by the
corresponding PHYAD input upon power-up / reset. For
example, if a given PHYAD input is resistively pulled low
(nominal 10 kΩ resistor recommended) then the corresponding LED output will be configured as an active high
driver. Conversely, if a given PHYAD input is resistively
pulled high, then the corresponding LED output will be configured as an active low driver. Refer to Figure 16 for an
example of LED & PHYAD connection to external components where, in this example, the PHYAD strapping results
in address 00011 or hex 03h or decimal 3.
Since the DP83843 is architected to support simultaneous
transmit and receive activity it is capable of supporting fullduplex switched applications with an aggregate throughput
of up to 200 Mb/s when operating in 100BASE-X mode.
Because the CSMA/CD protocol does not apply to fullduplex operation, the DP83843 simply disables its own
internal collision sensing and reporting functions and modifies the behavior of Carrier Sense (CRS) such that it indicates only receive activity to allow the full-duplex capable
MAC to operate properly.
3.3 Half Duplex vs. Full Duplex
The DP83843 supports both half and full duplex operation
at both 10 Mb/s and 100 Mb/s speeds.
VCC
1 κΩ
10 κΩ
LED_TX/PHYAD[1]
1 κΩ
10 κΩ
1 κΩ
10 κΩ
LED_COL/PHYAD[0]
All modes of operation (100BASE-TX, 100BASE-FX,
10BASE-T (both nibble and serial)) can run full-duplex
although it should be noted that full-duplex operation does
not apply to typical repeater implementations or AUI applications. Additionally, other than CRS and Collision reporting, all remaining MII signaling remains the same
regardless of the selected duplex mode.
LED_RX/PHYAD[2]
LED_LINK/PHYAD[3]
1 κΩ
10 κΩ
1 κΩ
10 κΩ
LED_FDPOL/PHYAD[4]
The state of each of the PHYAD inputs are latched into the
PHYCTRL register bits [4:0] (address 19h) at system
power-up/reset depending on whether a pull-up or pulldown resistor has been installed for each pin. 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 5.
VCC
Figure 16. PHYAD Strapping and LED Loading Example
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3.0 Configuration (Continued)
It is important to understand that while full Auto-Negotiation
with the use of Fast Link Pulse code words can interpret
and configure to support full-duplex, 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. Therefore, as specified in 802.3u, if a far-end link partner is transmitting forced full duplex 100BASE-TX for
example, the parallel detection state machine in the receiving station would be unable to detect the full duplex capability of the far-end link partner and would negotiate to a
half duplex 100BASE-TX configuration (same scenario for
10 Mb/s).
3.4 100 Mb/s Symbol Mode
In Symbol mode, all of the conditioning blocks in the transmit and receive sections of the 100BASE-X section are
bypassed. The 100BASE-X serial data received at the
RD+/− inputs of the DP83843 are recovered by the integrated PMD receiver, shifted into 5-bit parallel words and
presented to the MII receive outputs RXD[3:0] and
RX_ER/RXD[4]. All data, including Idles, passes through
the DP83843 unaltered other than for serial/parallel conversions.
Similarly, the TX_ER input pin is configured as the new
MSB (TXD[4]) to support the unaligned 5 bit transmit data.
Please refer to Section 2.2 for more information regarding
100BASE-FX operation.
3.6 10 Mb/s Serial Mode
The DP83843 allows for serial MII operation. In this mode,
the transmit and receive MII data transactions occur serially at a 10 MHz clock rate on the least significant bits
(RXD[0] and TXD[0]) of the MII data pins. This mode is
intended for use with a MAC based on a 10 Mb/s serial
interface.
While the MII control signals (CRS, RX_DV, TX_DV, and
TX_EN) as well as RX_EN and Collision are still used during 10 Mb/s Serial mode, some of the timing parameters
are different. Refer to Section 8 for AC timing details.
Both 10BASE-T and AUI can be configured for Serial
mode. Serial mode is not supported for 100 Mb/s operation.
Serial mode can be selected via hardware by forcing the
SERIAL10 pin (pin 69) to a logic low level prior to powerup/reset. The state of the SERIAL10 pin is latched into bits
11 and 12 of the 10BTSCR register (address 18h) as a
result of power-up/reset. These bits can be written through
software to control serial mode operation.
While in 10 Mb/s serial mode, RXD[3:1] will be placed in
All data, including Idles, passes through the DP83843 unal- TRI-STATE mode and RX_DV asserts coincident with CRS.
tered other than for serial/parallel conversions.
3.7 10 Mb/s AUI Mode
While in Symbol mode RX_DV and COL are held low and
TX_ER is used as the fifth bit and no longer functions as
TX_ER. Additionally, the CRS output reports the state of
signal detect as generated internally for 100BASE-TX and
externally for 100BASE-FX.
Placing the DP83843 in AUI mode enables the
FXTD/AUITD, FXRD/AUIRD, and FXSD/CD pin pairs to
allow for any AUI compliant external transceivers to be connected to the AUI interface. Placing the DP83843 in 10
Mb/s AUI mode disables the TPTD and TPRD transmit and
Symbol mode can be used for those applications where the receive pin pairs.
system design requires only the integrated PMD, clock The DP83843 also incorporates a THIN output control pin
recovery, and clock generation functions of the DP83843. for use with traditional AUI based CTI transceivers. This
This is accomplished either by configuring the CRS/SYM- output follows the state of bit 3 in the 10BTSCR register
BOL pin (pin 22) of the DP83843 to a logic low level prior to accessible through the serial MII.
power-up/reset or by setting bits 10 and 11 (BP_TX and
BP_RX respectively) of the LBR register (address 17h) The AUI/TP autoswitching allows transceiver autoswitching
through the serial MII port. Symbol mode only applies to between the AUI and TP outputs. At power up, the
autoswitch function is deselected in the 10BTSCR register
100BASE-X operation.
(bit 9 = 0) and the current mode, AUI or TP, is reported by
3.5 100BASE-FX Mode
the bit 13 of the 10BTSCR register (low for TPI and high for
The DP83843 will allow 100BASE-FX functionality by AUI).
bypassing the scrambler and descrambler and routing the When the auto-switch function is enabled (bit 9 = 1), it
PECL serial transmit and receive data through the separate allows the transceiver to automatically switch between TPI
FXTD/AUITD outputs and FXRD/AUIRD inputs respec- and AUI I/O’s. If there is an absence of link pulses, the
tively. Additionally, the signal detect indication from the opti- transceiver switches to AUI mode. Similarly, when the
cal transceiver is handled by the FXSD inputs. Placing the transceiver starts detecting link pulses, it switches to TP
DP83843 in 100BASE-FX mode disables the TPTD and mode. Switching from one mode to the other is done only
TPRD transmit and receive pin pairs.
after the current packet has been transmitted or received. If
Configuring the DP83843 for 100BASE-FX mode can be the twisted pair output is jabbering and it gets into link fail
accomplished either through hardware configuration or via state, then the switch to AUI mode is done only after the
jabbering has stopped, including the time it takes to unjab
software.
(unjab time). Also, if TPI mode is selected, transmit packet
The hardware configuration is set simply by tying the data are driven only by the TPI outputs and the AUI transCOL/FXEN pin (21) to a logic low level prior to power- mit outputs remain idle. Similar behavior applies when AUI
on/reset. The software setting is accomplished by setting mode is selected. The only difference in AUI mode is that
the BP_SCR bit (bit 12) of the LBR register (address 17h) the TP drivers continue to send link pulses; however, no
via MII serial management.
packet data is transmitted. The TPI receive circuitry and
The DP83843 can support either half-duplex or full-duplex the Link Integrity state machine are always active to enable
operation while in 100BASE-FX mode. Additionally, all MII this algorithm to function as described above.
signaling remains identical to that of 100BASE-TX operation.
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3.0 Configuration (Continued)
3.8 Repeater vs. Node
The DP83843 Carrier Sense (CRS) operation depends on
the value of the Repeater bit in the PHYCTRL register (bit
9, address 19h). When set high, the CRS output (pin 22) is
asserted for receive activity only. When set low, the CRS
output is asserted for either receive or transmit activity. The
default value for this bit is set by the THIN/REPEATER pin
(pin 63) at power-up/reset.
There is an internal pullup resistor for this pin which is
active during the power-up/reset period. If this pin is left
floating externally, then the device will configure to
Repeater mode as a result of power-up/reset. This pin
must be externally pulled low (typically 10 kΩ) in order to
configure the DP83843 for node operation.
When the repeater mode of operation is selected during
100 Mb/s operation, there are two parameters that are
directly effected.
First, CRS will only respond to receive activity.
Second, in compliance with the 802.3 standard, the Carrier
Integrity Monitor (CIM) function is automatically enabled for
detection and reporting of bad start of stream delimiters
(whereas in node mode the CIM is disabled).
diagnostic, this mode serves as quick functional verification
of the device.
In addition to Loopback mode, there are many other test
modes that serve similar loopback functions. These modes
are mutually exclusive with Loopback mode, enabling
Loopback mode disables the following test modes:
— CP_Loop (bits 9:7) of the Loopback and Bypass Register
(LBR). These bits control the 100 Mb/s loopback functions in more depth. A write of either a 0 or 1 to ‘Loopback’ causes these bits to be set to <000> which is
normal operation. At reset if FXEN is true then this will
default to, <011> which is Normal Fiber operation, otherwise it will default to <000>. The other modes are explained in the LBR definition table.
— Dig_Loop (bit 6) of the LBR. Digital loopback is used to
place the digital portions of the DP83843 into loopback
prior to the signals entering the analog sections. A write
of either a 0 or 1 to ‘Loopback’ causes this bits to be set
to 0 which is digital loopback disabled.
Bit 5 and Bit 4 of the LBR are automatically enabled in
Loopback mode. They are TWISTER (100 Mb/s) loopback
and TREX (10 Mb/s) loopback modes respectively.
The Dp83843 does not support 10Mb/s repeater applications.
3.9 Isolate Mode
An IEEE 802.3u compliant PHY connected to the mechanical MII interface is required to have a default value of one in
bit 10 of the Basic Mode Control Register (BMCR, address
00h.) The DP83843 will set this bit to one if the PHY
Address is set to 00000 upon power-up/hardware reset.
Otherwise, the DP83843 will set this bit to zero upon
power-up/hardware reset. Refer to Section 2.4.2 for information relating to the requirements for selecting a given
PHYAD.
With bit 10 in the BMCR set to one the DP83843 does not
respond to packet data present at TXD[3:0], TX_EN, and
TX_ER inputs and presents a high impedance on the
TX_CLK, RX_CLK, RX_DV, RX_ER, RXD[3:0], COL, and
CRS outputs. The DP83843 will continue to respond to all
management transactions.
While in Isolate mode, the TD+/− outputs will not transmit
packet data but will continue to source 100BASE-TX
scrambled idles or 10BASE-T normal link pulses.
3.10 Loopback
The DP83843 includes a Loopback Test mode for easy
board diagnostics. The Loopback mode is selected through
bit 14 (‘Loopback’) of the Basic Mode Control Register
(BMCR). The status of this mode may be checked in bit 3
of the PHY Status Register. Writing 1 to this bit enables MII
transmit data to be routed to the MII receive outputs. In
Loopback mode the data will not be transmitted on to the
media. This occurs for either 10 Mb/s or 100 Mb/s data.
Normal 10BASE-T, 10BASE-2, or 10BASE-5 operation, in
order to be standard compliant, also loops back the MII
transmit data to the MII receive data. However the data is
also allowed to be transmitted out the AUI or TP ports
(depending on the mode).
In 100 Mb/s Loopback mode the data is routed through the
PCS and PMA layers into the PMD sublayer before it is
looped back. Therefore, in addition to serving as a board
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4.0 Clock Architecture
serves to clock out the 125Mb/s serial bit stream for
100BASE-TX and 100BASE-FX applications. The 125
MHz clock is also routed to a counter where it is divided by
5 to produce the 25 MHz TX_CLK signal for the transmit
MII. Additionally, a set of phase related 250 MHz clock signals are routed to the Clock Recovery Module (CRM)
The DP83843 also incorporates Clock Recovery circuitry which act as a frequency reference to ensure proper opera(CRM) which extracts the 125 MHz clock from the 125 tion.
Mb/s receive datastream present during 100BASE-TX and For 10 Mb/s operation, the external 25 MHz reference is
100BASE-FX applications (Figure 17).
routed to a 100 MHz voltage controlled oscillator. The high
The 10 Mb/s receive clock requirements are handled by a frequency output from the oscillator is divided by five and
PLL which is tuned to extract a clock from either 10BASE-T serves to clock out the 10BASE-T or AUI serial bit stream
or AUI receive Manchester encoded data streams for 10 Mb/s applications. The 100 MHz clock is also routed
to a counter where it is divided by either eight or two to pro(Figure 17).
duce the 2.5 MHz or 10 MHz TX_CLK signal for the trans4.1 Clock Generation Module (CGM)
mit MII. Additionally, a set of phase related 100 MHz clock
For 100 Mb/s operation, the external 25 MHz reference is signals are routed to the Clock Recovery Module (CRM)
routed to a 250 MHz voltage controlled oscillator. The high which act as a frequency reference to ensure proper operafrequency output from the oscillator is divided by two and tion.
The DP83843 incorporates a sophisticated Clock Generation Module (CGM) design which allows full operation supporting all modes with a single 25 MHz (± 50 ppm) CMOS
level reference clock. As depicted in Figure 17, the single
25 MHz reference serves both the 100 Mb/s and 10 Mb/s
mode clocking requirements.
100M CLOCKING
Ref Clock to CRM
Divide by 5
VCO
(250 MHz)
Divide
by 2
25 MHz
MII TX_CLK
125 MHz serial
transmit clock
25 MHz
input
10M CLOCKING
VCO
(100 MHz)
20 MHz 10BASE-T
transmit clock
Divide
by 5
Divide
by 8
or 2
2.5 MHz or 10 MHz
MII TX_CLK
Ref Clock to CRM
Figure 17. Clock Generation Module BLOCK DIAGRAM
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4.0 Clock Architecture (Continued)
125Mb/s
Serial Data
Input
Phase
Detector
Phase Error
Processor
Deserializer
RXD [4:0]
Digital Loop
Filter
25 MHz
RX_CLK
Divide by 2
Phase to
Frequency
Converter
Frequency
Reference
From CGM
Frequency
Controlled
Oscillator
Figure 18. 100BASE-X Clock Recovery Module block diagram
CRS
10 Mb/s
Serial Data
Input
Phase
Detector
& CRS
Filter
Phase
Selector
Clk Gen
Serial /
Nibble
MUX
Frequency
Reference
From CGM
10 MHz
RX_CLK
RXD[0]
Serial Data
Deserializer
RXD[3:0]
2.5 MHz
RX_CLK
Figure 19. 10M Manchester Clock Recovery Module block diagram
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4.0 Clock Architecture (Continued)
4.2 100BASE-X Clock Recovery Module
The diagram in Figure 18 illustrates a high level block architecture of the 100BASE-X Clock Recovery circuit. The
125Mb/s serial binary receive data stream that has been
recovered by the integrated TP-PMD receiver is routed to
the input of the phase detector. A loop consisting of the
phase detector, phase error processor, digital loop filter,
phase to frequency converter, and the frequency controlled
oscillator then works to synthesize a 125 MHz clock based
on the receive data stream. This clock is used to latch the
serial data into the deserializer where the data is then converted to 5-bit code groups for processing by descrambler,
code-group alignment, and code-group decoder functional
blocks.
10BASE-T or AUI inputs, is routed to the input of the phase
detector. A loop consisting of the phase detector, digital
loop filter, phase selector, and the frequency generator
then works to synthesize a 20 MHz clock based on the
receive data stream. This clock is used to latch the serial
data into the deserializer where the data is then optionally
converted to 4-bit code groups for presentation to the MII
as nibble wide data clocked out at 2.5 MHz. Optionally, the
deserializer can be bypassed and the 10 Mb/s data is
clocked out serially at 10 MHz.
As a function of the Phase Detector, upon recognizing an
incoming 10 Mb/s datastream, Carrier Sense (CRS) is generated for use by the MAC.
4.4 Reference Clock Connection Options
4.3 10 Mb/s Clock Recovery Module
The two basic options for connecting the DP83843 to an
The diagram in Figure 19 illustrates a high level block archi- external reference clock consist of the use of either an
tecture of the 10 Mb/s Clock Recovery circuit. The 10 Mb/s oscillator or a crystal. Figure 20 and 21 illustrate the recserial Manchester receive data stream, from either the ommended connection for the two typical options.
25 MHz
Osc 50ppm
X1
X2
n/c
Figure 20. Oscillator Reference Clock Connection Diagram
33pF
X1
X2
33pF
25 MHz
Xtal 50ppm
Figure 21. Xtal Reference Clock Connection Diagram
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5.0 Reset Operation
Table 4. Latched pins at Reset
The DP83843 can be reset either by hardware or software.
A hardware reset may be accomplished either by asserting
the RESET pin during normal operation, or upon powering
up the device. A software reset is accomplished by setting
the reset bit in the Basic Mode Control Register.
Pin #
While either the hardware or software reset can be implemented at any time after device initialization, providing a
hardware reset, as described in Section 6.2 must be
implemented upon device power-up/initialization.
Omitting the hardware reset operation during the
device power-up/initialization sequence can result in
improper device operation.
Depending on the crystal starting up time, it is recommended to wait 20 ms after the supply has reached its
proper value before initiating a hardware reset.
Primary Function
Latched in at Reset
21
COL
FXEN
22
CRS
SYMBOL
38
LED_FDPOL
PHYAD4
39
LED_LINK
PHYAD3
40
LED_RX
PHYAD2
41
LED_TX
PHYAD1
42
LED_COL
PHYAD0
63
THIN
REPEATER
69
SERIAL10
SERIAL10
5.1 Power-up / Reset
When VCC is first applied to the DP83843 it takes some
amount of time for power to actually reach the nominal 5V
potential. This initial power-up time can be referred to as a
VCC ramp when VCC is “ramping” from 0V to 5V. When the
initial VCC ramp reaches approximately 4V, the DP83843
begins an internal reset operation which must be allowed
sufficient time, relative to the assertion and deassertion of
the RESET pin, to reset the device. There are two methods
for guaranteeing successful reset upon device power-up.
The first method accounts for those designs that utilize a
special power up circuit which, through hardware, will
assert the RESET pin upon power-up. In this case, the
deassertion (falling edge) of the RESET pin must not occur
until at least 500 µs after the time at which the VCC ramp
initially reached the 4V point.
5.3 Software Reset
A software reset is accomplished by setting the reset bit (bit
15) of the Basic Mode Control register (address 00h). This
bit is self clearing and, when set, will return a value of “1”
until the software reset operation has completed. The
period from the point in time when the reset bit is set to the
point in time when software reset has concluded is approximately 5 µs.
The software reset will reset the device such that all registers will be reset to default values and the hardware configuration values will be re-latched into the device (similar to
the power-up/reset operation). Driver code should wait 500
µs following a software reset before allowing further serial
MII operations with the DP83843.
The second method accounts for those applications which
produce a reset pulse sometime after the initial power-up of
the device. In this case, it is recommended that a positive
pulse, with a duration of at least 1 µs, be applied to the
RESET pin no sooner than 500 µs after the point in time
where the initial VCC ramp reached 4V.
In both methods described above, it is important to note
that the logic levels present at each of the hardware configuration pins of the DP83843 (see list below) are also
latched into the device as a function of the reset operation
(either hardware or software). These hardware configuration values are guaranteed to be latched into the DP83843
2 µs after the deassertion of the RESET pin.
The hardware configuration values latched into the
DP83843 during the reset operation are dependent on the
logic levels present at the device pins shown in Table 4
upon power-up.
During the power-up/ reset operation the LED1 through
LED5 pins are undefined, the SPEED10 will be asserted.
The 25 MHz clock reference must be applied for reset to
take effect.
5.2 Hardware Reset
A hardware reset is accomplished by applying a positive
pulse (TTL level), with a duration of at least 1 µs, to the
RESET pin of the DP83843 during normal operation. This
will reset the device such that all registers will be reset to
default values and the hardware configuration values will
be re-latched into the device (similar to the power-up/reset
operation).
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6.0 DP83843 Application
6.1 Typical Node Application
6.2 Power And Ground Filtering
Figure 22 illustrates a typical implementation of a 10/100
Mb/s node application. This is given only to indicate the
major circuit elements of such a design. It is not intended to
be a full circuit diagram. For detailed system level application information please contact your local National sales
representative.
Sufficient filtering between the DP83843 power and ground
pins placed as near to these pins as possible is recommended. Figure 23 suggests one option for device noise filtering including special consideration for the sensitive
analog power pins.
This cap is an optional component for
control of transmit transition time. An
inital value of 10pF is suggested.
TBD
49.9Ω
49.9 Ω
100pF
3kV
49.9 Ω
DP83843
Transmit
MII
{
--TX+
(73) TPTD-
--TX-
Optional 10pF Cap
connected to the center
tap of the transmit
transformer
TX_CLK (33)
GND
(67) TPRD+
MDC (35)
MDIO (34)
Management
RJ45-8
GND
(74) TPTD+
TX_EN (25)
TXD0 (31)
TXD1 (30)
TXD2 (29)
TXD3 (28)
TX_ER (24)
--RX+
VDD
(65) TPRDRXD0 (15)
RXD1 (14)
RXD2 (13)
RXD3 (12)
RX_ER (19)
RX_DV (20)
RX_CLK (18)
{
1.5KΩ
Receive
MII
--RX-
(66) VCM_CAP
49.9Ω
49.9Ω
100pF
3kV
49.9Ω
GND Optional 10pF Cap
connected to the center
tap of the receive
transformer
GND
RX_EN (23)
(78) TXAR100
10KΩ
NC
(50) FXRD+/AUIRD+
NC
NC
CRS/SYMBOL (22)
COL/FXEN (21)
Floating configures
the device for full
Auto-Negotiation
(49) FXRD-/AUIRDNC
NC
NC
(43) FXTD+/AUITD+
(44) FXTD-/AUITD-
AN0 (4)
AN1 (3)
(48) FXSD+/CD+
(47) FXSD-/CD-
This point should be tied
directly to the
TW_AVDD power pin
NC
0.1uF
0.0033uF
TW_AVDD
NC
NC
69.8KΩ
THIN/REPEATER (63)
(60) TWREF
10KΩ
SPEED10 (5)
GND
4.87KΩ
(61) BGREF
SERIAL10 (69)
NC
Active High Reset
Input (500us min)
RESET (1)
X1 (9)
X2 (8)
TWAGND
(42) LED_COL/PHYAD0
(41) LED_TX/PHYAD1
(40) LED_RX/PHYAD2
(39) LED_LINK/PHYAD3
(38) LED_FDPOL/PHYAD4
VDD
10KΩ
10KΩ
10KΩ
10KΩ
10KΩ
25MHz Xtal
50ppm
NC (62)
NC (59)
NC (58)
NC (56)
NC (55)
33pF
NC (2)
33pF
GND
1KΩ
VCC
1KΩ
1KΩ
GND
1KΩ
NC
NC
NC
NC
NC
NC
1KΩ
This configuration results
in a PHY address of 00001
GND
GND
Figure 22. Typical Implementation of 10/100 Mb/s Node Application
6.3 Power Plane Considerations
vided herein represent a more simplified approach when
compared to earlier recommendations. By reducing the
The recommendations for power plane considerations pronumber of instances of plane partitioning within a given
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6.0 DP83843 Application (Continued)
system design, empirical data has shown a resultant
improvement (reduction) in radiated emissions testing.
Additionally, by eliminating power plane partitioning within
the system VCC and system ground domains, specific
impedance controlled signal routing can remain uninterrupted.
By placing chassis ground on the top and bottom layers,
additional EMI shielding is created around the 125Mb/s signal traces that must be routed between the magnetics and
the RJ45-8 media connector. The example in Figure 24
assumes the use of Micro-Strip impedance control techniques for trace routing.
Figure 24 illustrates a way of creating isolated power
sources using beads on surface traces. No power or
ground plane partitioning is implied or required.
VCC FB
FB
TW_AGND(#64)
SUB_GND1(#70)
VCC
GND
VCC
0.1UF
IO_VDD1(#6),
IO_VDD2(#16),
IO_VDD3(#26),
IO_VDD5(#36)
CD_VDD0(#72),
CD_VDD1(#76),
PCS_VDD(#10)
CD_GND0(#71),
CD_GND1(#75),
PCS_VSS(#11)
DP83843
AUIFX_VDD(#46)
SUB_GND2(#77)
TR_AGND(#80)
ATP_GND(#57)
VCC
TR_AVDD(#79)
VCC
GND
ALL CAPS ARE 16V CERAMIC
= FERRITE BEAD TDK # HF70ACB-321611T
26Ω AT 100MHZ
GND
GND
0.001UF 0.1UF
10UF
IO_VSS1(#7),
IO_VSS2(#17),
IO_VSS3(#27),
IO_VSS4(#32),
IO_VSS5(#37)
GND
0.1UF
CP_AGND(#51)
TW_AVDD(#68)
GND
0.1UF
GND
AUIFX_GND(#45)
0.1UF 0.0033UF
0.001UF
CP_AVDD(#52)
FB
FB
CPTW_DVSS(#53)
VCC
VCC
0.0033UF
CPTW_DVDD(#54)
ALTHOUGH THE FB’S TO GND REDUCE NOISE ON
THESE TWO CRITICAL PINS, THEY MAY INCREASE
EMI EMISSIONS. THEREFORE, DEPENDING ON
YOUR APPLICATION THEY MAY OR MAY NOT BE
A BENEFIT.
FB
GND
0.1UF
GND
Figure 23. Power and Ground Filtering for the DP83843
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6.0 DP83843 Application (Continued)
Chassis Ground
Layer 1 (top)
Ground
Plane:
Chassis
Signal Routing
Magnetics
DP83843
RJ45
System
Ground
Layer 2
Signal Routing
Ground
Plane:
System Ground
DP83843
Magnetics
RJ45
System
Ground
Layer 3
System
VCC
VCC
Signal Routing
Planes:
DP83843
Magnetics
RJ45
System VCC
System
VCC
Chassis Ground
Layer 4 (bottom)
Ground
Plane:
Signal Routing
DP83843
Magnetics
RJ45
Chassis
Figure 24. Typical plane layout recommendation for DP83843
40
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6.0 DP83843 Application (Continued)
For applications where high reliability is required, it is recommended that additional ESD protection diodes be added
as shown below. There are numerous dual series connected diode pairs that are available specifically for ESD
protection. The level of protection will vary dependent upon
the diode ratings. The primary parameter that affects the
level of ESD protection is peak forward surge current. Typical specifications for diodes intended for ESD protection
range from 500mA (Motorola BAV99LT1 single pair diodes)
In the case of an installed Ethernet system however, the to 12A (STM DA108S1 Quad pair array).
network interface pins are still susceptible to external ESD
Since performance is dependent upon components used,
events. For example, a category 5 cable being dragged
board impedance characteristics, and layout, the circuit
across a carpet has the potential of developing a charge
should be completely tested to ensure performance to the
well above the typical 2kV ESD rating of a semiconductor
required levels.
device.
6.3.1 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 can
be implemented during the manufacturing process to
greatly reduce the occurrences of catastrophic ESD
events. After the system is assembled, internal components are usually relatively immune from ESD events.
DP83843 10/100
Vcc
RJ-45
Diodes placed on the
device side of the isolation transformer
Pin 1
TX±
Pin 2
Vcc
Pin 3
RX±
Pin 6
Figure 25. Typical DP83843 Network Interface with additional ESD protection
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7.0 User Information
7.1 Link LED While in Force 100Mb/s Good Link
not complete the negotiation since it is not advertising
100Mb/s capability. In an application in which the user only
desires 10Mb/s operation and is being sent 100Mb/s signals, then the correct operation is to never complete the
negotiation.
Type:
Information Hardware
Problem:
The Good Link LED (LED_LINK pin 39) will not assert
when the DP83843BVJE is programmed to force good link
in 100Mb/s mode. However, as long as the DP83843BVJE
is configured for forced 100BASE-X operation and good
link is forced for 100M operation, it will still be able to transmit data even though the good link LED is not lit.
7.3 10Mb/s Repeater Mode
Type:
Urgent Hardware
Problem:
The DP83843BVJE is not designed to support the use of
certain AUI attachments in repeater applications nor will it
When the DP83843BVJE is configured for forced good link directly support 10Mb/s repeater applications while in
in 100Mb/s mode, by setting bit 6 of the PCS register 10Mb/s serial or nibble mode.
(address 16h), the LINK_LED pin will not assert unless an Description:
internal state machine term, referred to as Cipher_In_Sync When implementing repeater applications which include a
(aka CIS), is asserted. The assertion of CIS is based on Coaxial Transceiver Interface (CTI) connected to the
the receive descrambler either being bypassed or becom- DP83843 AUI interface, CRS will be asserted due to transing synchronized with the receive scrambled data stream.
mit data because the transmit data is looped back to the
Description:
As long as the DP83843BVJE is configured for forced receive channel at the CTI transceiver. The assertion of
100BASE-X operation however, setting bit 6 of the PCS CRS during transmit will result in undue collisions at the
register (address 16h) will allow for transmission of data.
repeater controller.
Solution / Workaround:
Additionally, because there is no way to guarantee phase
In order to assert the Link LED while in Forced Good Link alignment of the 10MHz TX_CLK between multiple
PHYTERs in a serial 10M repeater application (same is
100Mb/s mode, the user may select one of two options:
true for 2.5MHz TX_CLK in 10Mb/s nibble mode), assum1: After setting bit 6 of the PCS register (address 16h), the ing each PHYTER is referenced to a single 25MHz X1
user may connect the DP83843BVJE to a known good far- clock signal, it is impossible to meet the input set and hold
end link partner that is transmitting valid scrambled IDLEs. requirements across all ports during a transmit operation.
This will assert the internal CIS term and, in turn, assert
Solution:
the Link LED.
2: After setting bit 6 of the PCS register (address 16h), the
user may then assert bit 12 of the LBR register (address
17h) to bypass the scrambler/descrambler. This will assert
the internal CIS term and, in turn, assert the Link LED. The
user should then clear bit 12 of the LBR register (address
17h) to re-engage the scrambler/descrambler to allow for
normal scrambled operation while in forced good link
100Mb/s mode.
It is not recommended that the DP83843BVJE be used for
AUI repeater applications where the transmit data is looped
back to the receive channel at the transceiver. (i.e. CTI).
Additionally, 10M serial and nibble repeater applications
are not currently directly supported.
7.4 Resistor Value Modifications
Type:
Urgent Hardware
7.2 False Link Indication When in Forced 10Mb/s
Problem:
Type:
To ensure optimal performance, the DP83843BVJE bandgap reference and receive equalization reference resistor
values require updating.
Informational Hardware
Problem:
The DP83843BVJE will indicate valid link status when Description:
forced to 10Mb/s (without Auto-Negotiation) while receiving The internal bandgap reference of the DP83843BVJE is
100BASE-TX scrambled Idles.
slightly offset which results in an offset in various IEEE
Description:
conformance parameters such as VOD.
The DP83843BVJE can incorrectly identify 100BASE-TX
scrambled Idles being received as valid 10BASE-T energy
and consequently indicate a valid link by the assertion of
the Link LED as well as by setting the Link Status bit (bit 2)
in the BMSR (reg 01h).
The internal adaptive equalization reference bias is also
slightly offset which can result in slightly reduced maximum
cable length performance.
Solution / Workaround:
In order to set the proper internal bandgap reference, it is
recommended that the value of the resistor connected to
Do not force 10Mb/s operation. Instead, use Auto-Negotia- the BGREF pin (pin 61) be set to 4.87KΩ (1/10th Watt
tion to advertise 10BASE-T full and/or half duplex (as resistor with a 1% tolerance is recommended). This resisdesired) via the ANAR register (reg 04h)
tor should be connected between the BGREF pin and
By using Auto-Negotiation and only specifying 10BASE-T TW_AGND.
(either half or full duplex), the DP83843BVJE will recognize In order to ensure maximum cable length performance for
the scrambled idles as a valid 100Mb/s stream, but it will 100BASE-TX operation, it is recommended that a 70KΩ
Solution / Workaround:
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resistor be placed between the TWREF pin (pin 60) and Description:
TW_AGND. (1/10th Watt resistor with a 1% tolerance is The Next Page Toggle bit is used only in Next Page operarecommended)
tions, and is used to distinguish one page from another.
The AutoNegotiation specification indicates that the toggle
7.5 Magnetics
bit should take on an initial value equal to that of bit 11 in
Type:
the ANAR, Reg 4h.
Informational Hardware
The DP83843BVJE incorrectly initializes this bit to 0, indeProblem:
pendent of the setting of bit 11 in the ANAR. Note that this
bit is a RESERVED bit in the 802.3 specification, and
N/A
defaults to 0 for all combinations of strap options.
Description:
If the user were to program both the Next Page bit, bit 15,
The DP83843BVJE has been extensively tested with the and the RESERVED bit, bit 11, to a logic 1 to perform a
following single package magnetics:
next page type negotiation, and the partner node also supported next page operation, then the negotiation would not
Valor PT4171 and ST6118
complete due to the initial wrong polarity of the toggle bit.
Bel Fuse S558-5999-39
Solution / Workaround:
Pulse H1086
Do not set RESERVED bit 11 (reg 04h) to a logic 1 if you
Solution / Workaround:
plan to perform next page operations.
Please note that one of the most important parameters that
is directly affected by the magnetics is 100BASE-TX Out- 7.7 Base Page to Next Page Initial FLP Burst
put Transition Timing. Even with the Valor PT4171S mag- Spacing
netics, it is possible, depending on the system design, Type:
layout, and associated parasitics, the output transition
Informational Hardware
times may need to be further controlled.
Problem:
In order to help control the output transition time of the
100BASE-TX transmit signal, the user may wish to place a In performing Next Page Negotiation, the FLP burst spaccapacitive load across the TPTD+/- pins as close to these ing on the initial burst when changing from the Base Page
pins as possible. However, because every system is differ- to the Next Page can be as long as 28ms. The 802.3u
ent, it is suggested that the system designer experiment specification, Clause 28 sets a maximum of 22.3ms. Thus,
with the capacitive value in order to obtain the desired there is a potential violation of 5.7ms.
results.
Description:
Note that the board layout, the magnetics, and the output This anomaly is due to the handshake between the arbitrasignal of the DP83843BVJE each contribute to the final rise tion and transmit state machines within the device. All other
and fall times as measured across the RJ45-8 transmit FLP burst to burst spacings, either base page or next page,
pins. It should be noted that excessive capacitive loading will be in the range of 13ms to 15ms.
across the TPTD+/- pins may result in improper transmit
return loss performance at high frequencies (up to 80MHz). Note that the violating burst causes NO functional probFinally, when performing 100Mb/s transmit return loss lems for either base page or next page exchange. This is
measurements, it is recommended that the DP83843BVJE due to the fact that the nlp_test_max_timer in the receive
state machine has a minimum specification of 50ms, and
be placed in True Quiet mode as described here:
the nlp_test_min_timer has a minimum specification of
In order to configure the PHYTER for "True Quiet" opera- 5ms. Thus, even if the transmitter waits 28ms vs. 22.3ms
tion, the following software calls should occur via the serial between FLP bursts, the nlp_test_max_timer will not have
MII management port following normal initialization of the come close to expiring. (50 + 5 - 28) = 27ms slack time.
device:
Solution.
- Write 01h to register 1Fh (this enables the extended
NOT APPLICABLE, Not a functional problem
register set)
- Write 02h to register 05h (this disables the NRZI 7.8 100Mb/s FLP Exchange Followed by Quiet
encoder, required for True Quiet)
Type:
- write 00h to register 1Fh (this exits the extended register Informational Hardware
set)
Problem:
- Set bit 9 of register 16h (this enables TX_QUIET which
The scenario is when the DP83843BVJE and another stastops transmitting 100M IDLEs))
tion are BOTH using AutoNegotiation AND advertising
7.6 Next Page Toggle Bit Initialization
100mb full or half. If both units complete the FLP exchange
properly, but the partner does NOT send any idles (a
Type:
FAULT condition), then the DP83843BVJE will get into a
Urgent Software
state in which it constantly sends 100mb idles and looks for
100mb idles from the partner.
Problem:
The DP83843BVJE's Next Page Toggle bit initializes to 0
independent of the value programmed in bit 11 of the
Advertised Abilities Register (ANAR), Reg 4h
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Description:
7.10 BAD_SSD Event Lockup
The symptoms of this problem include:
Type:
Register 1: Will show negotiation NOT complete (bit 5 = 0)
Urgent Hardware
Register 6: Will show a page received, then page receive Problem:
will be cleared on read of this register (bit 1 = 1, then bit 1 =
When the PHYTER receives a particular invalid data
0 if read twice)
sequence, it can get stuck in the RX_DATA state with an
Register 1a: Will have the data 00a3
invalid alignment. It will not recover until the link is broken
or software intervenes. The required data sequence looks
Solution / Workaround:
like a bad_ssd event (I,J, followed by symbol with MSB=0),
The workarounds include (these are mutually exclusive):
followed eventually by a good IJK pattern before seeing 10
1. Provide a 100mb data stream to the DP83843BVJE (fix consecutive idle bits. The data pattern also has to show up
on a specific alignment.
the problem)
2. Force 10mb mode by writing 0000h (half10) or 0100
(full10) to Register 0. This is a logical progression since
the 100mb side of the partner logic is down.
3. If you want to run AutoNegotiation again, with reduced
capabilities or all capabilities:
Turn off AutoNegotiation by writing a 0000h to Register 0.
(Need to do this to clear the DP83843 from sending idles.)
Description:
Root cause is that the transition from BAD_SSD state to
the CARRIER_DET state, which can only occur if there is a
single IDLE between packets, does not cause a re-loading
of the data alignment. If the Bad SSD event which preceded this met certain conditions defined above, then the
alignment logic is in an invalid state and the state machine
will not be able to detect an end of frame condition.
Change the capabilities to the desired configuration by writing to Register 4 (0061 for full10/half10, or 0021 for half10 Solution:
only, etc.)
There is no workaround available. Since the data pattern
Enable AutoNegotiation by writing a 1200 to Register 0. should never occur on a normally operating network, it has
been decided that no corrective action is required for the
(This restarts AutoNegotiation as well)
current product.
7.9 Common Mode Capacitor for EMI
improvement
Type:
Informational Hardware
Problem:
As with any high-speed design it is always practical to take
precautions regarding the design and layout of a system to
attempt to ensure acceptable EMI performance.
Description:
In an attempt to improve the EMI performance of a
DP83843BVJE based PCI Node Card, a 10pF capacitor
was installed from the center-tap of the primary winding of
the transmit transformer to gnd. This common mode capacitive filtering improved (reduced) the EMI emissions by several dB at critical frequencies when tested in an FCC
certified open field test site.
Solution / Workaround:
It is recommended that the footprint for a typical ceramic
chip cap be included on all new DP83843BVJE based
designs to allow for the experimentation of EMI improvement. Again, a component footprint for the 10pF capacitor
should be installed from the center-tap of the primary winding of the transmit transformer to system gnd. The inclusion
of this capacitor should have no deleterious effect on the
differential signalling of the transmitted signal. In fact,
because of the unique current source transmitter of the
DP83843BVJE, this center-tap cap has been shown to
actually improve some of the signal characteristics such as
rise/fall times and transmit return loss.
When including this component in a given design, it is recommended that it be connected from the transmit transformer primary center-tap directly to ground with an
absolute minimum of routing (preferably just an immediate
via to the ground plane).
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8.0 Register Block
8.1 Register Definitions
Register maps and address definitions are given in the following tables:
Table 5. Register Block - Phyter Register Map
Offset
Access
Tag
Description
00h
RW
BMCR
Basic Mode Control Register
01h
RO
BMSR
Basic Mode Status Register
02h
RO
PHYIDR1
PHY Identifier Register #1
03h
RO
PHYIDR2
PHY Identifier Register #2
04h
RW
ANAR
Auto-Negotiation Advertisement Register
05h
RW
ANLPAR
Auto-Negotiation Link Partner Ability Register
06h
RW
ANER
Auto-Negotiation Expansion Register
07h
RW
08h-0Fh
ANNPTR
Auto-Negotiation Next Page TX
Reserved
Reserved
10h
RO
PHYSTS
PHY Status Register
11h
RW
MIPSCR
MII Interrupt PHY Specific Control Register
12h
RO
MIPGSR
MII Interrupt PHY Generic Status Register
13h
RW
DCR
Disconnect Counter Register
14h
RW
FCSCR
False Carrier Sense Counter Register
15h
RW
RECR
Receive Error Counter Register
16h
RW
PCSR
PCS Sub-Layer Configuration and Status Register
17h
RW
LBR
Loopback and Bypass Register
18h
RW
10BTSCR
10BASE-T Status & Control Register
19h
RW
PHYCTRL
PHY Control Register
Reserved
Reserved
1Ah-1Fh
In the register definitions under the ‘Default’ heading, the following definitions hold true:
— RW = Read/Write; Register bit is able to be read and written to by software
— RO = Read Only; Register bit is able to be read but not written to by software
— L(H) = Latch/Hold; Register bit is latched and held until read by software based upon the occurrence of the corresponding event
— SC = Self Clear; Register bit will clear itself after the event has occurred without software intervention
— P = Permanent; Register bit is permanently set to the default value and no action will cause the bit to change
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8.0 Register Block (Continued)
Table 6. Basic Mode Control Register (BMCR) Address 00h
Bit
15
Bit Name
Reset
Default
0, RW/SC
Description
Reset:
1 = Initiate software Reset / Reset in Process
0 = Normal operation
This bit sets the status and control registers of the PHY to their
default states. This self-clearing bit returns a value of one until the
reset process is complete (approximately 1.2 ms for reset duration). Reset is finished once the Auto-Negotiation process has
begun or the device has entered its forced mode.
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
Speed Selection
Strap, RW
Speed Select:
1 = 100 Mb/s
0 = 10 Mb/s
Link speed is selected by this bit or by Auto-Negotiation if bit 12
of this register is set (in which case, the value of this bit is ignored)
At reset, this bit is set according to the strap configuration of the
AN0 and AN1 pins. After reset, this bit may be written to by software.
12
Auto-Negotiation En- Strap, RW
able
Auto-Negotiation Enable:
1 = Auto-Negotiation Enabled - bits 8 and 13 of this register are
ignored when this bit is set.
0 = Auto-Negotiation Disabled - bits 8 and 13 determine the link
speed and mode.
At reset, this bit is set according to the strap configuration of the
AN0 and AN1 pins. After reset, this bit may be written to by software.
11
Power Down
0, RW
Power Down:
1 = Power Down
0 = Normal Operation
Setting this bit configures the PHYTER for minimum power requirements.While in Power Down mode, the PHYTER is not capable of transmitting or receiving data on an active network.
Additionally, the PHYTER is not capable of "Wake-on-LAN" and
will not react to receive data while in Power Down mode. Power
Down mode is useful for scenarios where minimum system power
is desired (ie. Green PCs) but can only be used in systems that
have control over the PHYTER via Serial MII management.
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8.0 Register Block (Continued)
Table 6. Basic Mode Control Register (BMCR) Address 00h (Continued)
Bit
10
Bit Name
Isolate
Default
Strap, RW
Description
Isolate:
1 = Isolates the DP83843 from the MII with the exception of the
serial management. When this bit is asserted, the DP83843 does
not respond to TXD[3:0], TX_EN, and TX_ER inputs, and it presents a high impedance on its TX_CLK, RX_CLK, RX_DV,
RX_ER, RXD[3:0], COL and CRS outputs.
0 = Normal operation
If the PHY address is set to “00000” at power-up/reset the isolate
bit will be set to one, otherwise it defaults to 0. After reset this bit
may be written to by software.
9
Restart Auto-Negoti- 0, RW/SC
ation
Restart Auto-Negotiation:
1 = Restart Auto-Negotiation. Re-initiates the Auto-Negotiation
process. If Auto-Negotiation is disabled (bit 12 of this register
cleared), this bit has no function and should be cleared. This bit
is self-clearing and will return a value of 1 until Auto-Negotiation
is initiated by the Device, 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:
1 = Full Duplex operation. Duplex selection is allowed when AutoNegotiation is disabled (bit 12 of this register is cleared).
0 = Half Duplex operation
At reset this bit is set by either AN0 or AN1. After reset this bit may
be written to by software.
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 512BT. The COL signal
will be de-asserted within 4BT in response to the de-assertion of
TX_EN.
6:0
Reserved
0, RO
Reserved: Write ignored, read as zero
Table 7. Basic Mode Status Register (BMSR) Address 01h
Bit
15
Bit Name
100BASE-T4
Default
0, RO/P
Description
100BASE-T4 Capable:
1 = Device able to perform in 100BASE-T4 mode
0 = Device not able to perform in 100BASE-T4 mode
The PHYTER is NOT capable of supporting 100BASE-T4 and
this bit is permanently set to 0.
14
100BASE-TX Full
Duplex
1, RO/P
100BASE-TX Half
Duplex
1, RO/P
100BASE-TX Full Duplex Capable:
1 = Device able to perform 100BASE-TX in full duplex mode
0 = Device not able to perform 100BASE-TX in full duplex mode
13
100BASE-TX Half Duplex Capable:
1 = Device able to perform 100BASE-TX in half duplex mode
0 = Device not able to perform 100BASE-TX in half duplex mode
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8.0 Register Block (Continued)
Table 7. Basic Mode Status Register (BMSR) Address 01h (Continued)
Bit
12
Bit Name
Default
10BASE-T Full Duplex
1, RO/P
10BASE-T Half Duplex
1, RO/P
Description
10BASE-T Full Duplex Capable:
1 = Device able to perform 10BASE-T in full duplex mode
0 = Device not able to perform 10BASE-T in full duplex mode
11
10BASE-T Half Duplex Capable:
1 = Device able to perform 10BASE-T in half duplex mode
0 = Device not able to perform 10BASE-T in half duplex mode
10:7
Reserved
0, RO
Reserved: Write as 0, read as 0
6
Preamble
1, RO/P
Preamble suppression Capable:
Suppression
1 = Device able to perform management transaction with preamble suppressed*
0 = Device not able to perform management transaction with preamble suppressed
* Need minimum of 32 bits of preamble after reset.
5
Auto-Negotiation
Complete
0, RO
Auto-Negotiation Complete:
1 = Auto-Negotiation process complete
0 = Auto-Negotiation process not complete
4
Remote Fault
0, RO/LH
Remote Fault:
1 = Remote Fault condition detected (cleared on read or by a chip
reset). Fault criteria is Far End Fault Isolation or notification from
Link Partner of Remote Fault.
0 = No remote fault condition detected
3
Auto-Negotiation
Ability
1, RO/P
Link Status
0, RO/L
Auto Configuration Ability:
1 = Device is able to perform Auto-Negotiation
0 = Device is not able to perform Auto-Negotiation
2
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 link
status bit is implemented with a latching function, so that the occurrence of a link failure condition causes the Link Status bit to
become cleared and remain cleared until it is read via the management interface.
1
Jabber Detect
0, RO/L
Jabber Detect:
1 = Jabber condition detected
0 = No Jabber
This bit is implemented with a latching function so that the occurrence of a jabber condition causes it to become set until it is
cleared by a read to this register by the management interface or
by a Device Reset. This bit only has meaning in 10 Mb/s mode.
0
Extended Capability
1, RO/P
Extended Capability:
1 = Extended register capable
0 = Basic register capable only
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8.0 Register Block (Continued)
The PHY Identifier Registers #1 and #2 together form a unique identifier for the DP83843. The Identifier consists of a
concatenation of the Organizationally Unique Identifier (OUI), the vendor's model number and the model revision number. 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.
Table 8. PHY Identifier Register #1 (PHYIDR1) Address 02h
Bit
15:0
Bit Name
OUI_MSB
Default
Description
<00 1000 0000 OUI Most Significant Bits: This register stores bits 3 to 18 of the
0000 00>, RO/P OUI (080017h) to bits 15 to 0 of this register respectively. The
most significant two bits of the OUI are ignored (the IEEE standard refers to these as bits 1 and 2).
Table 9. PHY Identifier Register #2 (PHYIDR2) Address 03h
Bit
15:10
9:4
Bit Name
OUI_LSB
VNDR_MDL
3:0
MDL_REV
Default
Description
<01 0111>,
RO/P
OUI Least Significant Bits:
<00 0001>,
RO/P
Vendor Model Number:
<0000>, RO/P
Model Revision Number:
Bits 19 to 24 of the OUI (080017h) are mapped to bits 15 to 10
of this register respectively.
Six bits of vendor model number mapped to bits 9 to 4 (most significant bit to bit 9).
Four bits of vendor model revision number mapped to bits 3 to 0
(most significant bit to bit 3). This field will be incremented for all
major device changes.
This register contains the advertised abilities of this device as they will be transmitted to its Link Partner during AutoNegotiation.
Table 10. Auto-Negotiation Advertisement Register (ANAR) Address 04h
Bit
15
Bit Name
NP
Default
0, RW
Description
Next Page Indication:
0 = Next Page Transfer not desired
1 = Next Page Transfer desired
14
Reserved
0, RO/P
Reserved by IEEE: Writes ignored, Read as 0
13
RF
0, RW
Remote Fault:
1 = Advertises that this device has detected a Remote Fault
0 = No Remote Fault detected
12:11
Reserved
0, RW
Reserved for Future IEEE use: Write as 0, Read as 0
10
FDFC
0, RW
Full Duplex Flow Control:
1 = Advertise that the DTE(MAC) has implemented both the optional 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
9
T4
0, RO/P
100BASE-T4 Support:
1= 100BASE-T4 is supported by the local device
0 = 100BASE-T4 not supported
8
TX_FD
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
At reset, this bit is set by AN0/AN1. After reset, this bit may be
written to by software.
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8.0 Register Block (Continued)
Table 10. Auto-Negotiation Advertisement Register (ANAR) Address 04h (Continued)
Bit
7
Bit Name
TX
Default
Strap, RW
Description
100BASE-TX Support:
1 = 100BASE-TX is supported by the local device
0 = 100BASE-TX not supported
At reset, this bit is set by AN0/AN1. After reset, this bit may be
written to by software.
6
10_FD
Strap, RW
10BASE-T Full Duplex Support:
1 = 10BASE-T Full Duplex is supported by the local device
0 = 10BASE-T Full Duplex not supported
At reset, this bit is set by AN0/AN1. After reset, this bit may be
written to by software.
5
10
Strap, RW
10BASE-T Support:
1 = 10BASE-T is supported by the local device
0 = 10BASE-T not supported
At reset, this bit is set by AN0/AN1. After reset, this bit may be
written to by software.
4:0
Selector
<00001>, RW
Protocol Selection Bits:
These bits contain the binary encoded protocol selector supported by this node. <00001> indicates that this device supports IEEE
802.3 CSMA/CD.
Advertised abilities of the Link Partner as received during Auto-Negotiation.
Table 11. Auto-Negotiation Link Partner Ability Register (ANLPAR) Address 05h
Bit
15
Bit Name
NP
Default
0, RO
Description
Next Page Indication:
0 = Link Partner does not desire Next Page Transfer
1 = Link Partner desires Next Page Transfer
14
ACK
0, RO
Acknowledge:
1 = Link Partner acknowledges reception of the ability data word
0 = Not acknowledged
The Device's Auto-Negotiation state machine will automatically
control the use of this bit from the incoming FLP bursts. Software
should not attempt to write to this bit.
13
RF
0, RO
Remote Fault:
1 = Remote Fault indicated by Link Partner
0 = No Remote Fault indicated by Link Partner
12:10
Reserved
0, RO
Reserved for Future IEEE use: Write as 0, read as 0
9
T4
0, RO
100BASE-T4 Support:
1 = 100BASE-T4 is supported by the Link Partner
0 = 100BASE-T4 not supported by the Link Partner
8
TX_FD
0, RO
100BASE-TX Full Duplex Support:
1 = 100BASE-TX Full Duplex is supported by the Link Partner
0 = 100BASE-TX Full Duplex not supported by the Link Partner
7
TX
0, RO
100BASE-TX Support:
1 = 100BASE-TX is supported by the Link Partner
0 = 100BASE-TX not supported by the Link Partner
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8.0 Register Block (Continued)
Table 11. Auto-Negotiation Link Partner Ability Register (ANLPAR) Address 05h
Bit
6
Bit Name
10_FD
Default
0, RO
Description
10BASE-T Full Duplex Support:
1 = 10BASE-T Full Duplex is supported by the Link Partner
0 = 10BASE-T Full Duplex not supported by the Link Partner
5
10
0, RO
10BASE-T Support:
1 = 10BASE-T is supported by the Link Partner
0 = 10BASE-T not supported by the Link Partner
4:0
Selector
<00000>, RO
Protocol Selection Bits:
Link Partners’s binary encoded protocol selector.
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8.0 Register Block (Continued)
Table 11. Auto-Negotiation Link Partner Ability Register (ANLPAR) Address 05h
Bit
Bit Name
Default
Description
This register also contains the Link Partner Next Page contents.
15
NP
X RO
Next Page Indication:
0 = Link Partner does not desire another Next Page Transfer
1 = Link Partner desires another Next Page Transfer
14
ACK
X, RO
Acknowledge:
1 = Link Partner acknowledges reception of the ability data word
0 = Not acknowledged
The Device's Auto-Negotiation state machine will automatically
control the use of this bit from the incoming FLP bursts. Software
should not attempt to write to this bit.
13
MP
X, RO
Message Page:
1 = Message Page
0 = Unformatted Page
12
ACK2
X, RO
Acknowledge 2:
0 = Link Partner does not have the ability to comply to next page
message
1 = Link Partner has the ability to comply to next page message
11
TOGGLE
X, RO
Toggle:
0 = Previous value of the transmitted Link Code word equalled
logic one
1 = Previous value of the transmitted Link Code word equalled
logic zero
10:0
CODE
XXX, RW
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 "Unformatted Page," and the interpretation is application specific.
Table 12. Auto-Negotiation Expansion Register (ANER) Address 06h
Bit
Bit Name
Default
Description
15:5
Reserved
0, RO
Reserved: Writes ignored, Read as 0.
4
PDF
0, RO
Parallel Detection Fault:
1 = A fault has been detected via the Parallel Detection function
0 = A fault has not been detected via the Parallel Detection function
3
LP_NP_ABLE
0, RO
Link Partner Next Page Able:
Status indicating if the Link Partner supports Next Page negotiation. A one indicates that the Link Partner does support Next
Page.
2
NP_ABLE
1, RO/P
Next Page Able:
Indicates if this node is able to send additional “Next Pages.”
1
PAGE_RX
0, RO/L
Link Code Word Page Received:
This bit is set when a new Link Code Word Page has been received. Cleared on read of this register.
0
LP_AN_ABLE
0, RO
Link Partner Auto-Negotiation Able:
A one in this bit indicates that the Link Partner supports Auto-Negotiation.
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8.0 Register Block (Continued)
This register contains the next page information sent by this device to its Link Partner during Auto-Negotiation.
Table 13. Auto-Negotiation Next Page Transmit Register (ANNPTR) Address 07h
Bit
15
Bit Name
NP
Default
0, RW
Description
Next Page Indication:
0 = No other Next Page Transfer desired
1 = Another Next Page desired
14
Reserved
0, RO
Reserved: Writes ignored, read as 0
13
MP
1, RW
Message Page:
1 = Message Page
0 = Unformatted Page
12
ACK2
0, RW
Acknowledge2:
1 = Will comply with message
0 = Cannot comply with message
Acknowledge2 is used by the next page function to indicate that
a device has the ability to comply with the message received.
11
TOG_TX
1, RO
Toggle:
1 = Previous value of transmitted Link Code Word equalled logic
0
0 = Previous value of transmitted Link Code Word equalled logic
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
Toggle bit in the previously exchanged Link Code Word. The initial value is the inverse of bit 11 in the base Link Code Word
(ANAR), which makes the default value of TOG_TX = 1.
10:0
CODE
001, RW
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 "Unformatted Page," and the interpretation is application specific.
The default value of the CODE represents a Null Page as defined
in annex 28C of Clause 28.
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8.0 Register Block (Continued)
This register provides a single location within the register set for quick access to commonly accessed information.
Table 14. PHY Status Register (PHYSTS) Address 10h
Bit
15
Bit Name
Receive Error Latch
Default
0, RO/L
Description
Receive Error Latch:
1 = Receive error event has occurred since last read of RXERCNT
0 = No receive error event has occurred
14
CIM Latch
0, RO/L
Carrier Integrity Monitor Latch:
1 = Carrier Integrity Monitor has found an isolate event since last
read of DCR
0 = No Carrier Integrity Monitor isolate event has occurred
13
False Carrier Sense
Latch
0, RO/L
False Carrier Sense Latch:
1 = False Carrier event has occurred since last read of FCSCR
0 = No False Carrier event has occurred
12
Reserved
0, RO
Reserved: Write ignored, read as 0.
11
Device Ready
0, RO
Device Ready:
This bit signifies that the device is now ready to transmit data.
1 = Device Ready
0 = Device not Ready
10
Page Received
0, RO/L
Link Code Word Page Received:
This bit is set when a new Link Code Word Page has been received. Cleared on read of the ANER register.
9
Auto-Negotiation En- Strap, RO
abled
Auto-Negotiation Enabled:
1 = Auto-Negotiation Enabled.
0 = Auto-Negotiation Disabled.
8
MII Interrupt
0, RO/L
MII Interrupt Pending:
Indicates that an internal interrupt is pending and is cleared by the
current read. A read of this bit will clear the bit in the MIPGSR
(12h) also.
7
Remote Fault
0, RO/L
Remote Fault:
1 = Remote Fault condition detected (cleared on read of BMSR
register or by a chip reset). Fault criteria is Far end Fault Isolation
or notification from Link Partner of Remote Fault.
0 = No remote fault condition detected
6
Jabber Detect
0, RO/L
Jabber Detect:
1 = Jabber condition detected
0 = No Jabber
This bit is implemented with a latching function so that the occurrence of a jabber condition causes it to become set until it is
cleared by a read to the BMSR register by the management interface or by a Device reset. This bit only has meaning in 10 Mb/s
mode.
5
NWAY Complete
0, RO
Auto-Negotiation Complete:
1 = Auto-Negotiation complete
0 = Auto-Negotiation not complete
4
Reset Status
0, RO
Reset Status:
0 = Normal operation
1 = Reset in progress
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8.0 Register Block (Continued)
Table 14. PHY Status Register (PHYSTS) Address 10h (Continued)
Bit
3
Bit Name
Loopback Status
Default
0, RO
Description
Loopback:
1 = Loopback enabled
0 = Normal operation
2
Duplex Status
RO
Duplex:
This bit indicates duplex status and is determined from Auto-Negotiation or Forced Modes.
1 = Running in Full duplex mode
0 = Running in Half duplex mode
Note: This bit is only valid if Auto-Negotiation is enabled and
complete and there is a valid link or if Auto-Negotiation is disabled
and there is a valid link.
1
Speed Status
RO
Speed10:
This bit indicates the status of the speed and is determined from
Auto-Negotiation or Forced Modes.
1 = Running in 10Mb/s mode
0 = Running in 100 Mb/s mode
Note: This bit is only valid if Auto-Negotiation is enabled and
complete 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:
1 = Valid link established (for either 10 or 100 Mb/s operation)
0 = Link not established
The criteria for link validity is implementation specific.
This register implements the MII Interrupt PHY Specific Control register. Sources for interrupt generation include: Link
State Change, Jabber Event, Remote Fault, Auto-Negotiation Complete or any of the counters becoming half-full. Note
that the TINT bit operates independently of the INTEN bit. In other words, INTEN does not need to be active to generate
the test interrupt.
Table 15. MII Interrupt PHY Specific Control Register (MIPSCR) Address 11h
Bit
Bit Name
Default
Description
15:2
Reserved
0, RO
Reserved: Writes ignored, Read as 0
1
INTEN
0, RW
Interrupt Enable:
1 = Enable event based interrupts
0 = Disable event based interrupts
0
TINT
0, RW
Test Interrupt:
Forces the PHY to always generate an interrupt to allow testing
of the interrupt.
1 = Generate an interrupt at the end of each access
0 = Do not generate interrupt
This register implements the MII Interrupt PHY Generic Status Register.
Table 16. MII Interrupt PHY Generic Status Register (MIPGSR) Address 12h
Bit
15
Bit Name
MINT
Default
0, RO/COR
Description
MII Interrupt Pending:
Indicates that an interrupt is pending and is cleared by the current
read. A read of this will also clear the MII Interrupt bit (8) of the
PHYSTS (10h) register.
14:0
Reserved
0, RO
Reserved: Writes ignored, Read as 0
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8.0 Register Block (Continued)
This counter provides information required to implement the isolates attribute within the Repeater Port managed object
class of Clause 30 of the IEEE 802.3 specification.
Table 17. Disconnect Counter Register (DCR) Address 13h
Bit
15:0
Bit Name
DCNT[15:0]
Default
<0000h>, RW /
COR
Description
Disconnect Counter:
This 16 bit counter increments for each isolate event. Each time
the CIM detects a transition from the False Carrier state to the
Link Unstable state of the Carrier Integrity State Machine, the
counter increments. This counter rolls over when it reaches its
max count (FFFFh).
This counter provides information required to implement the FalseCarriers attribute within the MAU managed object class
of Clause 30 of the IEEE 802.3 specification.
Table 18. False Carrier Sense Counter Register (FCSCR) Address 14h
Bit
15:0
Bit Name
FCSCNT[15:0]
Default
<0000h>, RW /
COR
Description
False Carrier Event Counter:
This 16 bit counter increments for each false carrier event. A false
carrier event occurs when carrier sense is asserted without J/K
symbol detection. This counter rolls over when it reaches its max
count (FFFFh).
This counter provides information required to implement the aSymbolErrorDuringCarrier attribute within the PHY managed object class of Clause 30 of the IEEE 802.3 specification.
Table 19. Receive Error Counter Register (RECR) Address 15h
Bit
15:0
Bit Name
RXERCNT[15:0]
Default
<0000h>, RW /
COR
Description
RX_ER Counter:
This 16 bit counter is incremented for each receive error detected. The counter is incremented when valid carrier is present and
there is at least one occurrence of an invalid data symbol. This
event can increment only once per valid carrier event. If a collision is present, this attribute will not increment. This counter rolls
over when it reaches its max count (FFFFh).
Table 20. 100 Mb/s PCS Configuration and Status Register (PCSR) Address 16h
Bit
15
Bit Name
Single_SD
Default
0, RW
Description
SIngle Ended Signal Detect Enable:
1=Single Ended SD mode enabled
0=Single Ended SD mode disabled
14
FEFI_EN
Strap, RW
Far End Fault Indication Mode:
1 = FEFI mode enabled
0 = FEFI mode disabled
Note: If Auto-Negotiation is enabled, bit 12 of BMCR, this bit is
RO and forced to zero. Additionally, if FX_EN is set to a one then
this bit is RO and forced to a one.
13
DESCR_TO_RST
0, RW
Reset Descrambler Time-Out Counter:
1 = Reset Time-Out Counter
0 = Normal operation
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8.0 Register Block (Continued)
Table 20. 100 Mb/s PCS Configuration and Status Register (PCSR) Address 16h (Continued)
Bit
12
Bit Name
DESCR_TO_SEL
Default
0, RW
Description
Descrambler Time-out Select:
1 = Descrambler Timer set to 2 ms
0 = Descrambler Timer set to 722 µs
The Descrambler Timer selects the interval over which a minimum number of IDLES are required to be received to maintain
descrambler synchronization. The default time of 722 µs supports 100BASE-X compliant applications.
A timer time-out indicates a loss of descrambler synchronization
which cause the descrambler to restart its operation by immediately looking for IDLES.
The 2 ms option allows applications with Maximum Transmission
Units (packet sizes) larger than IEEE 802.3 to maintain descrambler synchronization (i.e., Token Ring/Fast-Ethernet switch/router applications).
11
DESCR_TO_DIS
0, RW
Descrambler Time-out Disable:
1 = Time-out Counter in the descrambler section of the receiver
disabled
0 = Time-out Counter enabled
10
LD_SCR_SD
0, RW
Load Scrambler Seed:
1 = Load Scrambler Seed continuously
0 = Normal operation
9
TX_QUIET
0, RW
100 Mps Transmit True Quiet Mode:
1 = Transmit True Quiet mode
0 = Normal mode
8:7
TX_PATTERN[1:0]
<00>, RW
100 Mps Transmit Test Pattern:
<00> = Normal operation
<01> = Send FEFI pattern
<10> = Send 1.28 µsperiod pattern (640 ns high/low time)
<11> = Send 160 ns period pattern (80 ns high/low time)
6
F_LINK_100
0, RW
Force Good Link in 100 Mb/s:
1 = Force 100 Mb/s Good Link status
0 = Normal 100 Mb/s operation
This bit is useful for diagnostic purposes.
5
CIM_DIS
Strap, RW
Carrier Integrity Monitor Disable:
1 = Carrier Integrity Monitor function disabled (Node/Switch operation)
0 = Carrier Integrity Monitor function enabled (Repeater operation)
The THIN/REPEATER determines the default state of this bit to
automatically enable or disable the CIM function as required for
IEEE 802.3 compliant applications. The value latched into this bit
at power-on/reset is the compliment of the value forced on the
THIN/REPEATER input. After power-on/reset, software may enable or disable this function independent of repeater or
node/switch mode.
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8.0 Register Block (Continued)
Table 20. 100 Mb/s PCS Configuration and Status Register (PCSR) Address 16h (Continued)
Bit
4
Bit Name
CIM_STATUS
Default
0, RO
Description
Carrier Integrity Monitor Status:
This bit indicates the status of the Carrier Integrity Monitor function. This status is optionally muxed out through the TX_LED pin
when the LED_TXRX_MODE bits (8:7) of the PHYCTRL register
(address 19h) are set to either <10> or <01>.
1 = Unstable link condition detected
0 = Unstable link condition not detected
3
CODE_ERR
0, RW
Code Errors:
1 = Forces code errors to be reported with the value 5h on
RXD[3:0] and with RX_ER set to 1.
0 = Forces code errors to be reported with the value of 6h on
RXD[3:0] and with RX_ER set to 1.
2
PME_ERR
0, RW
Premature End Errors:
1 = Forces premature end errors to be reported with the value 4h
on RXD[3:0] and with RX_ER set to 1.
0 = Forces premature end errors to be reported with the value 6h
on RXD[3:0] and with RX_ER set to 1. Premature end errors are
caused by the detection of two IDLE symbols in the receive data
stream prior to the T/R symbol pair denoting end of stream delimiter.
1
LINK_ERR
0, RW
Link Errors:
1 = Forces link errors to be reported with the value 3h on
RXD[3:0] and with RX_ER set to 1.
0 = Data is passed to RXD[3:0] unchanged and with RX_ER set
to 0.
0
PKT_ERR
0, RW
Packet Errors:
1 = Forces packet errors (722 s time-out) to be reported with the
value 2h on RXD[3:0] and with RX_ER set to 1.
0 = Data is passed to RXD[3:0] unchanged and with RX_ER set
to 0.
Table 21. Loopback & Bypass Register (LBR) Address 17h
Bit
Bit Name
Default
Description
15
Reserved
0, RO
Reserved: Writes ignored, read as 0.
14
BP_STRETCH
0, RW
Bypass LED Stretching:
This will bypass the LED stretching and the LEDs will reflect the
internal value.
1 = Bypass LED stretching
0 = Normal operation
13
BP_4B5B
Strap, RW
Bypass 4B5B Encoding and 5B4B Decoding:
This bit is set according to the strap configuration of the SYMBOL
pin at power-up/reset. After reset this bit may be written to by software.
1 = 4B5B encoder and 5B4B decoder functions bypassed
0 = Normal 4B5B and 5B4B operation
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8.0 Register Block (Continued)
Table 21. Loopback & Bypass Register (LBR) Address 17h (Continued)
Bit
12
Bit Name
BP_SCR
Default
Strap, RW
Description
Bypass Scrambler/Descrambler Function:
This bit is set according to the strap configuration of the SYMBOL
pin or the FXEN pin at power-up/reset. After reset this bit may be
written to by software.
1 = Scrambler and descrambler functions bypassed
0 = Normal scrambler and descrambler operation
11
BP_RX
Strap, RW
Bypass Receive Function:
This bit is set according to the strap configuration of the SYMBOL
pin at power-up/reset. After reset this bit may be written to by software.
1 = Receive functions (descrambler and symbol decoding functions) bypassed.
0 = Normal operation.
10
BP_TX
Strap, RW
Bypass Transmit Function:
This bit is set according to the strap configuration of the SYMBOL
pin at power-up/reset. After reset this bit may be written by software.
1 = Transmit functions (symbol encoder and scrambler) bypassed
0 = Normal operation
9:7
100_DP_CTL
Strap, RW
100Mps Data Path Control Bits:
At reset, if FXEN is true then this will default to <011>, else it will
default to <000>. These bits control the 100Mps loopback function in CorePhy as follows:
<000> Normal Mode
<001> CorePhy Loopback
<010> Reserved
<011> Normal Fiber
<100> Reserved
<101> Reserved
<110> Reserved
<111> Reserved
Note: A write to the Loopback bit (14) of the BMCR (00h) will
override the value set in this register.
6
RESERVED
0, RO
Reserved: Writes as 0, read as 0
5
TW_LBEN
0, RW
TWISTER Loopback Enable:
1 = TWISTER loopback
0 = Normal mode
Note: A write to the Loopback bit (14) of the BMCR (00h) will
override the value set in this register.
4
10Mb_ENDEC_LB
0, RW
10 Mb/s ENDEC Loopback:
1 = 10Mb/s ENDEC loopback
0 = Normal TREX operation
Note: A write to the Loopback bit (14) of the BMCR (00h) will
override the value set in this register.
3
RESERVED
0, RO
Reserved: Writes as 0, read as 0
2
RESERVED
0, RO
Reserved: Writes as 0, read as 0
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8.0 Register Block (Continued)
Table 21. Loopback & Bypass Register (LBR) Address 17h (Continued)
Bit
Bit Name
Default
Description
1
RESERVED
0, RO
Reserved: Writes as 0, read as 0
0
RESERVED
0, RO
Reserved: Writes as 0, read as 0
Table 22. 10BASE-T Control & Status Register (10BTSCR) Address 18h
Bit
Bit Name
Default
Description
15:14
RESERVED
0, RO
Reserved: Writes ignored, read as 0
13
AUI_TPI
0, RO
TREX Operating Mode:
This bit shows the current operating mode of TREX as chosen by
the Auto-Switch function.
1 = AUI mode
0 = TPI mode
12
RX_SERIAL
Strap, RW
10BASE-T RX Serial Mode:
This bit is set according to the strap configuration of the
SERIAL10 pin at power-up/reset. After reset this bit may be written to by software.
1 = 10BASE-T rx Serial mode selected
0 = 10BASE-T rx Nibble mode selected
Serial mode is not supported for 100 Mb/s operation.
11
TX_SERIAL
Strap, RW
10BASE-T TX Serial Mode:
This bit is set according to the strap configuration of the
SERIAL_10 pin at power-up/reset. After reset this bit may be written to by software.
1 = 10BASE-T tx Serial mode selected
0 = 10BASE-T tx Nibble mode selected
Serial mode is not supported for 100 Mb/s operation.
10
POL_DS
0, RW
Polarity Detection & Correction Disable:
1 = Polarity Sense & Correction disabled
0 = Polarity Sense & Correction enabled
9
AUTOSW_EN
0, RW
AUI/TPI Autoswitch:
1 = Enable autoswitch
0 = Disable autoswitch function
The use of autoswitch should be strictly limited to applications
that do not support Auto-Negotiation. Do not enable Auto-Negotiation when enabling autoswitch as this may result in improper
operation.
8
LP_DS
0, RW
Link Pulse Disable:
1 = Reception of link pulses ignored, good link condition forced
0 = Good link not forced, link pulses observed for good link
7
HB_DS
0, RW
Heartbeat Disable:
1 = Heartbeat function disabled
0 = Heartbeat function enabled
When the device is configured for full duplex operation, this bit will
be ignored (the collision/heartbeat function has no meaning in
Full Duplex mode). HB_DS will read back as 1 if in Full Duplex
mode or Repeater mode.
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8.0 Register Block (Continued)
Table 22. 10BASE-T Control & Status Register (10BTSCR) Address 18h (Continued)
Bit
6
Bit Name
Default
LS_SEL
0, RW
Description
Low Squelch Select:
Selects between standard 10BASE-T receiver squelch threshold
and a reduced squelch threshold that is useful for longer cable
applications.
1 = Low Squelch Threshold selected
0 = Normal 10BASE-T Squelch Threshold selected
5
AUI_SEL
0, RW
AUI Select:
1 = Select AUI interface
0 = Select TPI interface
4
JAB_DS
0, RW
Jabber Disable:
Enables or disables the Jabber function when the device is in
10BASE-T Full Duplex or 10BASE-T TREX Loopback mode
(TREX_LBEN bit 4 in the LBR, address 17h).
1 = Jabber function disabled
0 = Jabber function enabled
3
THIN_SEL
0, RW
Thin Ethernet Select:
1 = Asserts THIN pin (pin 63)
0 = Deasserts THIN pin (pin 63)
This pin may be used as a general purpose select pin.
2
RX_FILT_DS
0, RW
TPI Receive Filter Disable:
1 = Disable TPI receive filter
0 = Enable TPI receive filter
1
RESERVED
0, RO
Reserved: Writes ignored, read as 0
0
RESERVED
0, RO
Reserved: Writes as 0, read as 0
Table 23. PHY Control Register (PHYCTRL) Address 19h
Bit
Bit Name
Default
Description
15
RESERVED
0, RO
Reserved: Writes ignored, read as 0
14
RESERVED
0, RO
Reserved: Writes ignored, read as 0
13:12
TW_EQSEL[1:0]
<00>, RW
TWISTER Equalization Select:
Used in combination to select the 4 equalization modes. Modes
3, 2, 1 should be accessible to external device pin for debug purposes.
<11> = Equalization off
<10> = Equalization on
<01> = Adaptive Equalization
<00> = Full Adaptive Equalization
11
TW_BLW_DS
0, RW
TWISTER Base Line Wander Disable:
1 = BLW Feedback loop disabled
0 = BLW Feedback loop enabled
10
RESERVED
0, RO
Reserved: Writes ignored, read as 0
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8.0 Register Block (Continued)
Table 23. PHY Control Register (PHYCTRL) Address 19h (Continued)
Bit
9
Bit Name
REPEATER
Default
Strap, RW
Description
Repeater/Node Mode:
1 = Repeater mode
0 = Node mode
In repeater mode the Carrier Sense (CRS) output from the device
is asserted due to receive activity only. In Node mode, and not
configured for full duplex operation, CRS is asserted due to either
receive or transmit activity. In 100 Mb/s operation the CIM monitor is disabled. In Repeater mode HB_DS is enabled (bit 7 register 10BTSCR(18h))
This bit is set according to the strap configuration of the REPEATER pin at power-up/reset.
8:7
LED_TXRX_MODE
<00>, RW
LED_TX/RX Mode Select:
<11> = LED_RX indicates both RX and TX activity and LED_TX
indicates interrupt. Interrupt signal is active high.
<10> = LED_RX indicates both RX and TX activity and LED_TX
indicates Carrier Integrity Monitor status.Interrupt signal is active
high.
<01> = LED_RX indicates RX activity only and LED_TX indicates
Carrier Integrity Monitor status.
<00> = Normal LED_TX and LED_RX operation.
Note: Using LED_TX to indicate Carrier Integrity Monitor status
is useful for network management purposes in 100BASE-TX
mode. This mode only works if the PHY_Address_2 is strapped
low because the PHYTER does not properly implement the Activity LED function if LED_RX/PHYAD[2] is strapped high.
6
LED_DUP_MODE
0, RW
LED_DUP Mode Select:
1 = LED_FDPOL configured to indicate polarity reversal in
10BASE-T mode, and full duplex in 100BASE-TX mode
0 = LED_FDPOL configured to indicate full duplex in all operating
modes.
5
FX_EN
Strap, RW
Fiber Mode Enable:
This bit is set by the FX_EN at power-on/reset or by software after
reset. If this bit is set then the signals FEFI_EN and BP_SCR are
driven internally. When this bit is set, fiber mode enabled, AutoNegotiation must be disabled.
1 = Fiber Mode enabled
0 = Fiber Mode disabled
4:0
PHYADDR[4:0]
(STRAP), RW
PHY Address:
The values of the PHYAD[4:0] pins are latched to this register at
power-up/reset. The first PHY address bit transmitted or received
is the MSB of the address (bit 4). A station management entity
connected to multiple PHY entities must know the appropriate address of each PHY. A PHY address of <00000> that is latched in
to the part at power up/reset will cause the Isolate bit of the
BMCR (bit 10, register address 00h) to be set.
After power up/reset the only way to enable or disable isolate
mode is to set or clear the Isolate bit (bit 10) of BMCR (address
00). After power up/reset writing <00000> to bits [4:0] of this register will not cause the part to enter isolate mode.
62
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9.0 Electrical Specifications
Absolute Maximum Ratings
Supply Voltage (VCC)
Recommended Operating Conditions
-0.5 V to 7.0 V
Input Voltage (DCIN)
-0.5 V to VCC + 0.5 V
Supply voltage (VDD)
Output Voltage (DCOUT)
-0.5 V to VCC + 0.5 V
Ambient Temperature (TA)
Storage Temperature
ECL Signal Output Current
ESD Protection
o
o
-65 C to 150 C
-50mA
2000 V
Min
4.75
Typ
5.0
Max Units
5.25
V
0
70
X1 Input Frequency Stability
-50
+50
(over temperature)
X1 Input Duty Cycle
Center Frequency (XFC)
35
65
25
o
C
PPM
%
MHz
All preliminary electrical specifications are based on IEEE 802.3u requirements and internal design considerations.
These specifications will not become final until complete verification of the DP83843.
Thermal Characteristics*
Maximum Case Temperature
Max
96
Maximum Die Temperature
104.7
Theta Junction to Case (Tjc)
Units
oC
oC
1.1
oC
/W
Theta Junction to Ambient (Tja) degrees Celsius/Watt - No Airflow @ 1.0W
42.7
oC
/W
Theta Junction to Ambient (Tja) degrees Celsius/Watt - 225 LFPM Airflow @ 1.0W
35.3
oC
/W
Theta Junction to Ambient (Tja) degrees Celsius/Watt - 500 LFPM Airflow @ 1.0W
30.4
oC
/W
Theta Junction to Ambient (Tja) degrees Celsius/Watt - 900 LFPM Airflow @ 1.0W
26.9
oC
/W
*Valid for Phyters with data code 9812 or later, for earlier data codes please contact your National Sales Representative for data.
63
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9.0 Electrical Specifications (Continued)
9.1 DC Electrical Specification
Symbol
VIH
VIL
VIM
IIH
Pin Types
Parameter
I
I/O
I/O, Z
Input High Voltage
Min
Typ
Max
Units
2.0
V
AN0 and AN1
VCC - 1.0
V
X1
VCC - 1.0
V
I
I/O
I/O, Z
Input Low Voltage
0.8
V
AN0 and AN1
1.0
V
X1
1.0
V
(VCC/2)
+0.5
V
10
µA
-100
µA
10
µA
X2 = N.C.
100
µA
0.4
V
AN0 and AN1 Input Mid Level
Voltage
I
I/O
I/O, Z
I
I/O
I/O, Z
Pin Unconnected
(VCC/2)
-0.5
(VCC/2)
Input High Current VIN = VCC
X1
IIL
Conditions
X2 = N.C.
Input Low Current VIN = GND
X1
VOL
O, Z
I/O
I/O, Z
Output Low
Voltage
IOL = 4 mA
VOH
O, Z
I/O
I/O, Z
Output High
Voltage
IOL = -4 mA
VOL
LED
SPEED10
Output Low
Voltage
IOL = 2.5 mA
VOH
LED
SPEED10
Output High
Voltage
IOL = -2.5 mA
IOZ1
I/O, Z
O, Z
TRI-STATE
Leakage
VOUT = VCC
10
µA
IOZ2
I/O, Z
O, Z
TRI-STATE
Leakage
VOUT = GND
-10
µA
VCC - 0.5
V
0.4
VCC - 0.5
V
V
RINdiff
TPRD+/−
Differential Input
Resistance
see Test
Conditions section
5
6
VTPTD_100
TPTD+/−
100M Transmit
Voltage
see Test
Conditionssection
.95
1
VTPTDsym
TPTD+/−
100M Transmit
see Test
Voltage Symmetry Conditions section
-2
VTPTD_10
TPTD+/−
10M Transmit
Voltage
2.2
CIN1
I
CMOS Input
Capacitance
8
pF
CIN2
I
PECL Input
Capacitance
10
pF
see Test
Conditions section
64
2.5
kΩ
1.05
V
+2
%
2.8
V
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9.0 Electrical Specifications (Continued)
Symbol
Pin Types
Parameter
Conditions
Min
Typ
Max
Units
COUT1
O
Z
CMOS Output
Capacitance
8
pF
COUT2
O
Z
PECL Output
Capacitance
10
pF
SDTHon
TPRD+/−
100BASE-TX
Signal detect turnon thresh
SDTHoff
TPRD+/−
100BASE-TX
Signal detect turnoff thresh
200
VTH1
TPRD+/−
10BASE-T Receive Threshold
300
585
mV
VTH2
TPRD+/−
10BASE-T Receive Low
Squelch Threshold
150
300
mV
VDIFF
FXSD+/−,
FXRD+/−
PECL Input Voltage Differential
see Test
Conditions section
300
VCM
FXSD+/−,
FXRD+/−
PECL Common
Mode Voltage
see Test
Conditions section
VCC - 2.0
VCC - 0.5
mV
IINECL
FXSD+/−,
FXRD+/−
PECL Input
Current
VIN = VOLmax or
-300
300
µA
VOHECL
FXTD+/−
PECL Output High VIN = VIHmax
Voltage
VCC - 1.125
VCC - 0.78
V
VOLECL
FXTD+/−
PECL Output Low VIN = VILmax
Voltage
VCC - 1.86
VCC - 1.515
V
VODaui
AUITD+/−
Differential Output see Test
Voltage
Conditions section
± 550
± 1200
mV
VOBaui
AUITD+/−
Differential Idle
Output Voltage
Imbalance
see Test
Conditions section
40
VDSaui
AUIRD+/−,
AUICD+/−
Differential
Squelch
Threshold
see Test
Conditions section
± 160
± 300
mV
Idd100
Supply
100BASE-TX
(Full Duplex)
see Test
Conditions section
135
150
mA
Idd10
Supply
10BASE-TX
(Full Duplex)
see Test
Conditions section
100
110
mA
IddFX
Supply
100BASE-FX
(Full Duplex)
see Test
Conditions section
100
115
mA
IddAN
Supply
Auto-Negotiation
see Test
Conditions section
100
120
mA
IddPD
Supply
Power Down
see Test
Conditions section
25
30
mA
1000
mV diff pk-pk
mV diff pk-pk
mV
VOHmax
65
mV
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9.0 Electrical Specifications (Continued)
9.2 CGM Clock Timing
X1 IN
TX_CLK OUT
T2.0.2
T2.0.1
Parameter
Description
Notes
Min
Typ
Max
Units
T2.0.1
X1 to TX_CLK Delay
-3
+3
ns
T2.0.2
TX_CLK Duty Cycle
35
65
%
Max
Units
300
ns
9.3 MII Serial Management AC Timing
MDC
T3.0.1
T3.0.4
MDIO (OUTPUT)
MDC
T3.0.2
MDIO (INPUT)
Parameter
Description
T3.0.3
VALID DATA
Notes
Min
Typ
T3.0.1
MDC to MDIO (Output) Delay Time
0
T3.0.2
MDIO (Input) to MDC Setup Time
10
ns
T3.0.3
MDIO (Input) to MDC Hold Time
10
ns
T3.0.4
MDC Frequency
2.5
66
MHz
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9.0 Electrical Specifications (Continued)
9.4 100 Mb/s AC Timing
9.4.1 100 Mb/s MII Transmit Timing
TX_CLK
T4.1.1
TXD[3:0]
TX_EN
TX_ER
Parameter
T4.1.1
T4.1.2
VALID DATA
Description
Notes
TXD[3:0], TX_EN, TX_ER Data Setup to
TX_CLK
T4.1.2
Min
Typ
Max Units
100 Mb/s Normal mode
14
ns
TXD[4:0] Data Setup to TX_CLK
100 Mb/s Symbol mode
10
ns
TXD[3:0], TX_EN, TX_ER Data Hold from
TX_CLK
100 Mb/s Normal mode
-1
ns
TXD[4:0] Data Hold from TX_CLK
100 Mb/s Symbol mode
-1
ns
9.4.2 100 Mb/s MII Receive Timing
RX_EN
T4.2.4
T4.2.1
T4.2.2
RX_CLK
T4.2.3
RXD[3:0]
RX_DV
RX_ER
Parameter
VALID DATA
Description
Notes
Min
Typ
Max
Units
T4.2.1
RX_EN to RX_CLK, RXD[3:0], RX_ER,
RX_DV Active
All 100 Mb/s modes
15
ns
T4.2.2
RX_EN to RX_CLK, RXD[3:0], RX_ER,
RX_DV TRI-STATE
All 100 Mb/s modes
25
ns
T4.2.3
RX_CLK to RXD[3:0], RX_DV, RX_ER Delay 100 Mb/s Normal mode
10
30
ns
RX_CLK to RXD[4:0], Delay
100 Mb/s Symbol mode
10
30
ns
RX_CLK Duty Cycle
All 100 Mb/s modes
35
65
%
T4.2.4
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9.0 Electrical Specifications (Continued)
9.4.3 100BASE-TX Transmit Packet Latency Timing
TX_CLK
TX_EN
TXD
TPTD+/-
Parameter
T4.3.1
T4.3.1
IDLE
(J/K)
Description
TX_CLK to TPTD+/− Latency
Notes
DATA
Min
Typ
Max
Units
100 Mb/s Normal mode
6.0
bits
100 Mb/s Symbol mode
6.0
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 TPTD± pins. 1 bit time = 10ns in 100 Mb/s mode. For Symbol mode, because TX_EN has no meaning, latency
is measured from the first rising edge of TX_CLK occurring after the assertion of a data nibble on the Transmit MII to the first bit (MSB) of that nibble as
output from the TPTD± pins. 1 bit time = 10 ns in 100 Mb/s mode.
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9.0 Electrical Specifications (Continued)
9.4.4 100BASE-TX Transmit Packet Deassertion Timing
TX_CLK
TXD
TX_EN
T4.4.1
TPTD+/-
Parameter
T4.4.1
DATA
(T/R)
Description
Notes
TX_CLK to TPTD+/−
Deassertion
IDLE
Min
Typ
Max
Units
100 Mb/s Normal mode
6.0
bits
100 Mb/s Symbol mode
6.0
bits
Note: Deassertion is determined by measuring the time from the first rising edge of TX_CLK occurring after the deassertion of TX_EN to the first bit of the
“T” code group as output from the TPTD± pins. For Symbol mode, because TX_EN has no meaning, Deassertion is measured from the first rising edge of
TX_CLK occurring after the deassertion of a data nibble on the Transmit MII to the last bit (LSB) of that nibble when it deasserts on the wire. 1 bit time = 10
ns in 100 Mb/s mode.
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9.0 Electrical Specifications (Continued)
9.4.5 100BASE-TX Transmit Timing
TPTD+/+1 RISE
-1 RISE
-1 FALL
+1 FALL
T4.5.2
T4.5.1
T4.5.1
T4.5.1
T4.5.1
TPTD+/EYE PATTERN
T4.5.2
Parameter
T4.5.1
T4.5.2
Description
Min
Typ
Max
Units
3
4
5
ns
100 Mb/s Rise/Fall Mismatch
500
ps
100 Mb/s TPTD+/−
Transmit Jitter
1.4
ns
100 Mb/s TPTD+/− Rise and
Fall Times
Notes
see Test Conditions section
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.
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9.0 Electrical Specifications (Continued)
9.4.6 100BASE-TX Receive Packet Latency Timing
TPRD+/-
IDLE
DATA
(J/K)
T4.6.1
CRS
T4.6.2
RXD[3:0]
RX_DV
RX_ER/RXD[4]
Parameter
Description
Notes
Min
Typ
Max
Units
T4.6.1
Carrier Sense on Delay
100 Mb/s Normal mode
17.5
bits
T4.6.2
Receive Data Latency
100 Mb/s Normal mode
21
bits
100 Mb/s Symbol mode
12
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: TPRD± voltage amplitude is greater than the Signal Detect Turn-On Threshold Value.
9.4.7 100BASE-TX Receive Packet Deassertion Timing
TPRD+/-
DATA
IDLE
(T/R)
T4.7.1
CRS
RXD[3:0]
RX_DV
RX_ER/RXD[4]
Parameter
T4.7.1
Description
Carrier Sense Off Delay
Notes
100 Mb/s Normal mode
Min
Typ
Max
Units
21.5
bits
Note: Carrier Sense Off Delay is determined by measuring the time from the first bit of the “T” code group to the deassertion of Carrier Sense.
Note: 1 bit time = 10 ns in 100 Mb/s mode.
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9.0 Electrical Specifications (Continued)
9.4.8 100BASE-FX Transmit Packet Latency Timing
TX_CLK
TX_EN
TXD
T4.8.1
FXTD+/-
Parameter
T4.8.1
IDLE
(J/K)
Description
TX_CLK to FXTD+/− Latency
Notes
DATA
Min
Typ
Max
Units
100 Mb/s Normal mode
4.0
bits
100 Mb/s Symbol mode
4.0
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 FXTD± pins. For Symbol mode, because TX_EN has no meaning, Latency is measured from the first rising
edge of TX_CLK occurring after the assertion of a data nibble on the Transmit MII to the first bit (MSB) of that nibble when it first appears at the FXTD±
outputs.
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9.0 Electrical Specifications (Continued)
9.4.9 100BASE-FX Transmit Packet Deassertion Timing
TX_CLK
TXD
TX_EN
T4.9.1
FXTD+/-
Parameter
T4.9.1
DATA
(T/R)
Description
Notes
TX_CLK to FXTD+/−
Deassertion
IDLE
Max
Units
100 Mb/s Normal mode
Min
Typ
4.0
bits
100 Mb/s Symbol mode
4.0
bits
Note: Deassertion is determined by measuring the time from the first rising edge of TX_CLK occurring after the deassertion of TX_EN to the first bit of the
“T” code group as output from the FXTD± pins. For Symbol mode, because TX_EN has no meaning, Deassertion is measured from the first rising edge of
TX_CLK occurring after the deassertion of a data nibble on the Transmit MII to the last bit (LSB) of that nibble when it deasserts as output from the FXTD±
pins. 1 bit time = 10 ns in 100 Mb/s mode.
9.4.10 100BASE-FX Receive Packet Latency Timing
FXRD+/-
IDLE
DATA
(J/K)
T4.10.1
CRS
T4.10.2
RXD[3:0]
RX_DV
RX_ER/RXD[4]
Parameter
Description
T4.10.1
Carrier Sense On Delay
T4.10.2
Receive Data Latency
Notes
100 Mb/s Normal mode
Min
Typ
Max
Units
17.5
bits
100 Mb/s Normal mode
19
bits
100 Mb/s Symbol mode
19
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.
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9.0 Electrical Specifications (Continued)
9.4.11 100BASE-FX Receive Packet Deassertion Timing
FXRD+/-
DATA
IDLE
(T/R)
T4.11.1
CRS
RXD[3:0]
RX_DV
RX_ER/RXD[4]
Parameter
T4.11.1
Description
Carrier Sense Off Delay
Notes
Min
Typ
100 Mb/s Normal mode
Max
Units
21.5
bits
Note: Carrier Sense Off Delay is determined by measuring the time from the first bit of the “T” code group to the deassertion of Carrier Sense.
Note: 1 bit time = 10 ns in 100 Mb/s mode.
9.5 10 Mb/s AC Timing
9.5.12 10 Mb/s MII Transmit Timing
TX_CLK
T5.12.
1
TXD[3:0]
TX_EN
TX_ER
Parameter
T5.12.
2
VALID DATA
Description
Notes
Min
Typ
Max Units
T5.12.1
TXD[3:0], TX_EN Data Setup to TX_CLK
10 Mb/s Nibble mode
25
TXD0 Data Setup to TX_CLK
10 Mb/s Serial mode
25
ns
T5.12.2
TXD[3:0], TX_EN Data Hold from TX_CLK
10 Mb/s Nibble mode
-1
ns
TXD0 Data Hold from TX_CLK
10 Mb/s Serial mode
-1
ns
74
ns
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9.0 Electrical Specifications (Continued)
9.5.13 10 Mb/s MII Receive Timing
RX_EN
T5.13.4
T5.13.1
T5.13.
2
RX_CLK
T5.13.3
RXD[3:0]
RX_DV
RX_ER
VALID DATA
Parameter
Description
Notes
Min
Typ
Max
Units
T5.13.1
RX_EN to RX_CLK, RXD[3:0], RX_DV Active All 10 Mb/s modes
10
ns
T5.13.2
RX_EN to RX_CLK, RXD[3:0], RX_DV TRISTATE
25
ns
T5.13.3
RX_CLK to RXD[3:0], RX_DV, RX_ER Delay 10 Mb/s Nibble mode
210
ns
RX_CLK to RXD[3:0], RX_DV, RX_ER Delay 10 Mb/s Serial mode
40
60
ns
T5.13.4
RX_CLK Duty Cycle
35
65
%
All 10 Mb/s modes
190
All 10 Mb/s modes
9.5.14 10BASE-T Transmit Timing (Start of Packet)
TX_CLK
T5.14.
1
TX_EN
T5.14.2 T5.14.
3
TXD
T5.14.4
TPTD+/-
Parameter
Description
Notes
Min
Typ
Max
Units
T5.14.1
Transmit Enable Setup Time from the 10 Mb/s Nibble mode
Rising Edge of TX_CLK
10 Mb/s Serial mode
25
ns
25
ns
T5.14.2
Transmit Data Setup Time from the
Rising Edge of TX_CLK
10 Mb/s Nibble mode
25
ns
10 Mb/s Serial mode
25
ns
T5.14.3
Transmit Data Hold Time from the
Rising Edge of TX_CLK
10 Mb/s Nibble mode
-1
ns
10 Mb/s Serial mode
-1
T5.14.4
Transmit Output Delay from the
Rising Edge of TX_CLK
10 Mb/s Nibble mode
6.8
bits
10 Mb/s Serial mode
2.5
bits
ns
Note: 1 bit time = 100 ns in 10 Mb/s mode for both nibble and serial operation.
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9.0 Electrical Specifications (Continued)
9.5.15 10BASE-T Transmit Timing (End of Packet)
T5.15.1
TX_CLK
TX_EN
0
T5.15.2
0
TPTD+/-
TPTD+/-
Parameter
T5.15.1
T5.15.2
T5.15.3
1
T5.15.3
1
Description
Notes
Transmit Enable Hold Time from the 10 Mb/s Nibble mode
Rising Edge of TX_CLK
10 Mb/s Serial mode
Min
Typ
Max
Units
-1
ns
-1
ns
End of Packet High Time
10 Mb/s Nibble mode
250
ns
(with ‘0’ ending bit)
10 Mb/s Serial mode
250
ns
End of Packet High Time
10 Mb/s Nibble mode
250
ns
(with ‘1’ ending bit)
10 Mb/s Serial mode
250
ns
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9.0 Electrical Specifications (Continued)
9.5.16 10BASE-T Receive Timing (Start of Packet)
1ST SFD BIT DECODED
1
0
1
TPRD+/T5.16.1
CRS
T5.16.
RX_CLK
T5.16.4
RXD
T5.16.
RX_DV
Parameter
Description
Notes
Min
Typ
Max
Units
1
µs
T5.16.1
Carrier Sense Turn On Delay
(TPRD+/− to CRS)
10 Mb/s Nibble mode
10 Mb/s Serial mode
1
µs
T5.16.2
Decoder Acquisition Time
10 Mb/s Nibble mode
3.6
µs
10 Mb/s Serial mode
3.2
µs
10 Mb/s Nibble mode
17.3
bits
10 Mb/s Serial mode
10
bits
10 Mb/s Nibble mode
10
bits
10 Mb/s Serial mode
4.5
bits
Max
Units
T5.16.3
Receive Data Latency
T5.16.4
SFD Propagation Delay
Note: 10BASE-T receive Data 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 for both nibble and serial operation.
9.5.17 10BASE-T Receive Timing (End of Packet)
1
0
IDLE
1
TPRD+/RX_CLK
T5.17.
1
CRS
Parameter
T5.17.1
Description
Carrier Sense Turn Off Delay
Notes
Min
Typ
10 Mb/s Nibble mode
1.1
us
10 Mb/s Serial mode
450
ns
77
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9.0 Electrical Specifications (Continued)
9.5.18 10 Mb/s AUI Timing
1
0
T5.18.
0
AUITD+/T5.18.
T5.18.
AUIRD+/-
Parameter
Description
T5.18.1
AUI Transmit Output High Before
Idle
T5.18.2
AUI Transmit Output Idle Time
T5.18.3
AUI Receive End of Packet Hold
Time
Notes
Min
Typ
Max
200
Units
ns
8000
225
ns
ns
Note: The worst case for T5.18.1 is data ending in a ‘0’.
9.5.19 10 Mb/sHeartbeat Timing
TXE
TXC
T5.19.
T5.19.
COL
Parameter
T5.19.1
T5.19.2
Description
CD Heartbeat Delay
CD Heartbeat Duration
Notes
Min
Typ
Max
Units
10 Mb/s Nibble mode
700
ns
10 Mb/s Serial mode
700
ns
10 Mb/s Nibble mode
700
ns
10 Mb/s Serial mode
700
ns
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9.0 Electrical Specifications (Continued)
9.5.20 10 Mb/s Jabber Timing
TXE
T5.20.1
T5.20.
TPTD+/-
COL
Parameter
T5.20.1
T5.20.2
Description
Notes
Jabber Activation Time
Jabber Deactivation Time
Min
Typ
Max
Units
10 Mb/s Nibble mode
26
ms
10 Mb/s Serial mode
26
ms
10 Mb/s Nibble mode
500
ms
10 Mb/s Serial mode
500
ms
9.5.21 10BASE-T Normal Link Pulse Timing
T5.21.2
T5.21.1
Parameter
Description
T5.21.1
Pulse Width
T5.21.2
Pulse Period
Notes
Min
Typ
Max
100
8
16
Units
ns
24
ms
Note: These specifications represent both transmit and receive timings.
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9.0 Electrical Specifications (Continued)
9.6 Auto-Negotiation Fast Link Pulse (FLP) Timing
T6.21.
T6.21.
T6.21.
1
T6.21.1
FAST LINK PULSE(S)
CLOCK
PULSE
DATA
PULSE
CLOCK
PULSE
T6.21.
T6.21.4
T6.21.5
FLP BURST
Parameter
FLP BURST
Description
T6.21.1
Clock, Data Pulse Width
T6.21.2
Clock Pulse to Clock Pulse
Period
T6.21.3
Clock Pulse to Data Pulse
Period
T6.21.4
Number of Pulses in a Burst
T6.21.5
Burst Width
T6.21.6
FLP Burst to FLP Burst Period
Notes
Min
Typ
Max
100
ns
139
µs
55.5
69.5
µs
17
33
#
111
Data = 1
Units
125
2
8
ms
24
ms
Max
Units
2.7
ns
Note: These specifications represent both transmit and receive timings.
9.7 100BASE-X Clock Recovery Module (CRM) Timing
NOMINAL WINDOW
CENTER
FXRD+/TPRD+/-
T7.21.1
IDEAL WINDOW RECOGNITION
Parameter
T7.21.1
Description
Notes
CRM Window Recognition Region
Min
-2.7
Typ
Note: The Ideal window recognition region is ± 4 ns.
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9.0 Electrical Specifications (Continued)
9.7.22 100BASE-X CRM Acquisition Time
FXSD+
OR SD+ INTERNAL
T7.22.1
FXRD+/-
Parameter
T7.22.1
PLL PRIOR TO LOCK
Description
CRM Acquisition
PLL LOCKED
Notes
Min
Typ
100 Mb/s
Max
Units
250
µs
Note: The Clock Generation Module (CGM) must be stable for at least 100 µs before the Clock Recovery Module (CRM) can lock to receive data.
Note: SD+ internal comes from the internal Signal Detect function block when in 100BASE-TX mode.
9.7.23 100BASE-TX Signal Detect Timing
TPRD +/-
T7.23.
T7.23.2
SD+ INTERNAL
Parameter
Description
Notes
Min
Typ
Max
Units
T7.23.1
SD Internal Turn-on Time
1
ms
T7.23.2
SD Internal Turn-off Time
300
µs
Note: The SD internal signal is available as an external signal in Symbol mode.
Note: The signal amplitude at TPRD +/− is TP-PMD compliant.
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9.0 Electrical Specifications (Continued)
9.8 Reset Timing
VCC
T8.23.
T8.23.
T8.23.
HARDWARE
RESET (OPTION #1)
HARDWARE
RESET (OPTION #2)
32 CLOCKS
MDC
T8.23.
LATCH-IN OF HARDWARE
CONFIGURATION PINS
T8.23.5
INPUT
OUTPUT
DUAL FUNCTION PINS
BECOME ENABLED AS OUTPUTS
Parameter
Description
Notes
Min
Typ
Max
Units
500
µs
1
µs
500
µs
T8.23.1
Internal Reset Time
T8.23.2
Hardware RESET Pulse Width
T8.23.3
Post Reset Stabilization time
MDIO is pulled high for 32 bit serial manprior to MDC preamble for reg- agement initialization
ister accesses
T8.23.4
Hardware Configuration Latch- Hardware Configuration Pins are dein Time from the Deassertion of scribed in the Pin Description section
Reset (either soft or hard)
800
ns
T8.23.5
Hardware Configuration pins
transition to output drivers
800
ns
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
Note: Software Reset should be initiated no sooner then 500 µs after power-up or the deassertion of hardware reset.
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.
Note: The timing for Hardware Reset Option 2 is equal to parameter T1 plus parameter T2 (501 µs total).
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9.0 Electrical Specifications (Continued)
9.9 Loopback Timing
TX_CLK
TX_EN
TXD[3:0]
CRS
T9.23.1
RX_CLK
RX_DV
RXD[3:0]
Parameter
T9.23.1
Description
TX_EN to RX_DV Loopback
Notes
Min
Typ
Max
Units
100 Mb/s
240
ns
10 Mb/s Serial mode
650
ns
10 Mb/s Nibble mode
2
µs
Note: Due to the nature of the descrambler function, all 100BASE-X 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-X timing specified is based on device delays after the initial 550µs “dead-time”.
Note: During loopback (all modes) both the TPTD± or FXTD/AUITD± outputs remain inactive by default.
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9.0 Electrical Specifications (Continued)
9.10 Isolation Timing
CLEAR BIT 10 OF BMCR
(RETURN TO NORMAL OPERATION
FROM ISOLATE MODE)
T10.23.1
H/W OR S/W RESET
(WITH PHYAD ≠ 00000)
T10.23.2
MODE
ISOLATE
Parameter
Description
Notes
Max
Units
T10.23.1
From software clear of bit 10 in
the BMCR register to the transition from Isolate to Normal Mode
100
µs
T10.23.2
From Deassertion of S/W or H/W
Reset to transition from Isolate to
Normal mode
500
µs
84
Min
NORMAL
Typ
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10.0 Test Conditions
This section contains information relating to the specific
test environments, including stimulus and loading parameters, for the DP83843. These test conditions are categorized in the following subsections by each type of
pin/interface including:
of this load is 50 pF. The diagram in Figure 28 illustrates
the test configuration.
It should be noted that the current source and sink limits
are set to 4.0 mA when testing/loading the MII output pins.
The current source and sink limits are set to 2.5 mA when
testing/loading the LED output pins.
— FXTD/AUITD+/− Outputs sourcing AUI
— FXTD/AUITD+/− Outputs sourcing 100BASE-FX
10.4 TPTD+/− Outputs (sourcing 10BASE-T)
— CMOS Outputs i.e. MII and LEDs
When configured for 10BASE-T operation, these differen— TPTD+/− Outputs sourcing 100BASE-TX
tial outputs source Manchester encoded binary data at
10BASE-T logic levels. These outputs are loaded as illus— TPTD+/− Outputs sourcing 10BASE-T
trated in Figure 29. Note that the transmit amplitude meaAdditionally, testing conditions for Idd measurements are surements are made across the secondary of the transmit
included.
transformer as specified by the IEEE 802.3 specification.
10.1 FXTD/AUITD+/− Outputs (sourcing AUI levels)
10.5 TPTD+/− Outputs (sourcing 100BASE-TX)
When configured for 100BASE-TX operation, these differWhen configured for AUI operation, these differential out- ential outputs source scrambled 125Mb/s data at MLT-3
puts source Manchester encoded 10 Mb/s data at AUI logic logic levels. These outputs are loaded as illustrated in
levels. These outputs are loaded as illustrated in Figure 26. Figure 29. Note that the transmit amplitude and rise/fall
time measurements are made across the secondary of the
10.2 FXTD/AUITD+/− Outputs (sourcing PECL)
transmit transformer as specified by the IEEE 802.3u specWhen configured for 100BASE-FX operation, these differ- ification.
ential outputs source unscrambled 125 Mb/s data at PECL
logic levels. These outputs are loaded as illustrated in 10.6 Idd Measurement Conditions
Figure 27.
The DP83843 PHYTER is currently tested for total device
Idd under four operational modes:
10.3 CMOS Outputs (MII and LED)
Each of the MII and LED outputs are loaded with a con- — 100BASE-TX Full Duplex (max packet length / min IPG)
trolled current source to either ground or VCC for testing — 10BASE-TX Half Duplex (max packet length / min IPG)
Voh, Vol, and AC parametrics. The associated capacitance — 100BASE-FX Full Duplex (max packet length / min IPG)
AUITD
200Ω
39Ω
AUIRD
AUICD
200Ω
100µH TRANSFORMER
39Ω
DB-15 CONNECTOR
39Ω
39Ω
78Ω
.01µF
.01µF
TYPICAL AUI
TRANSMIT LOAD
27µH
Figure 26. AUI Test Load
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10.0 Test Conditions (Continued)
AUITD/FXTD+
DP83843
PHYTER
AUITD/FXTD-
50Ω
50Ω
VTT = VCC - 2.2V
VTT
VTT
Figure 27. 100BASE-FX Test Load
VCC
CURRENT SOUR
50pF
DP83843
PHYTER
CMOS OUTPUT
50pF
CURRENT SINK
GND
Figure 28. CMOS Output Test Load
TPTD+
100Ω
DP83843
PHYTER
100Ω
TPTD10/100
AC COUPLING
TRANSFORMER
Figure 29. 10/100 Twisted Pair Load (zero meters)
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DP83843 PHYTER
11.0 Package Dimensions inches (millimeters) unless otherwise noted
Molded Plastic Quad Flat Package
Order Number DP83843BVJE
NC Package Number VJE80A
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