78Q2123R/F - Maxim Integrated

DESCRIPTION

The 78Q2123 and 78Q2133, MicroPHYTM, are the

smallest 10BASE-T/100BASE-TX Fast Ethernet

transceivers in the market. They include integrated

MII, ENDECs, scrambler/descrambler, dual-speed

clock recovery, and full-featured auto-negotiation

functions. The transmitter includes an on-chip pulse-

shaper and a low-power line driver. The receiver has

an adaptive equalizer and a baseline restoration

circuit required for accurate clock and data recovery.

The transceiver interfaces to Category-5 unshielded

twisted pair (Cat-5 UTP) cabling for 100BASE-TX

applications, and Category-3 unshielded twisted pair

(Cat-3 UTP) for 10BASE-T applications. The MDI is

connected to the line media via dual 1:1 isolation

transformers. No external filter is required. Interface

to the MAC is accomplished through an IEEE-802.3

compliant Media Independent Interface (MII). The

78Q2123/78Q2133 are intended to serve the

embedded Ethernet market, tailored specifically to the

needs of game consoles, broadband modems,

printers, set top boxes and audio/visual equipment. It

is designed for low-power consumption and operates

from a single 3.3V supply. The 78Q2123 is rated for

commercial temperature range and the 78Q2133 is

rated for industrial temperature range.

FEATURES

xSmallest 10/100 PHY available

x10BASE-T/100BASE-TX IEEE-802.3 compliant

TX and RX functions requiring a dual 1:1 isolation

transformer interface to the line

xIntegrated MII, 10BASE-T/100BASE-TX ENDEC,

100BASE-TX scrambler/descrambler, and

full-featured auto-negotiation function

xFull duplex operation capable

xAutomatic MDI/MDI-X cross over correction

xRegister-programmable transmit amplitude

xAutomatic polarity correction during auto-

negotiation and 10BASE-T signal reception

xPower-saving and power-down modes including

transmitter disable

x2 Programmable LED indicators (Link and

Activity by default)

xUser programmable Interrupt pin

Packages:

32-QFN (5x5 mm) and 32-TQFN (5x5mm)

xLow Power (~290mW)

xSingle 3.3 V r0.3V Supply

x78Q2123 rated for 0°C to 70°C operation

x78Q2133 rated for -40°C to 85°C operation

RXC

TXC

RXD

TXD

SMI

MII

100M

10M

Scrambler,

Parallel/Serial

Parallel/Serial,

Manchester Encoder

MRZ/NRZI

MLT3 Encoder

TX CLK GEN

Auto

MDI-X

Mux

Tx/Rx

Rx/Tx

Carrier Sense,

Collision Detect

CLK

Recovery

10M

100M

Adaptive EQ,

Baseline Wander Correct,

MLT3 Decode, NRZI/NRZ

Clock Reference LEDs

CLKIN 25MHz

Link

Act

Rev. 2.0 1

DATA SHEET

78Q2123/78Q2133 MicroPHY™

10/100BASE-TX Transceiver

SimplifyingSystemIntegration

Pulse Shaper

and Filter

Manchester Decoder,

Parallel/Serial

MII

Registers Serial/Parallel

Descrambler,

5B/4B Decoder

78Q2123/78Q2133 Data Sheet DS_21x3_001

Table of Contents

1 Functional Description .......................................................................................................................... 5

1.1

General

........................................................................................................................................... 5

1.1.1 Power Management............................................................................................................ 5

1.1.2 Analog Biasing and Supply Regulation................................................................................ 5

1.1.3 Clock Selection.................................................................................................................... 5

1.1.4 Transmit Clock Generation.................................................................................................. 5

1.1.5 Receive Signal Qualification................................................................................................ 6

1.1.6 Receive Clock Recovery ..................................................................................................... 6

1.2

100BASE-TX OPERATION........................................................................................................... 6

1.2.1 100BASE-TX Transmit........................................................................................................ 6

1.2.2 100BASE-TX Receive......................................................................................................... 6

1.2.3 PCS Bypass Mode (Auto-negotiate must be off)................................................................. 6

1.3

10BASE-T OPERATION ............................................................................................................... 7

1.3.1 10BASE-T Transmit ............................................................................................................ 7

1.3.2 10BASE-T Receive ............................................................................................................. 7

1.3.3 Polarity Correction............................................................................................................... 7

1.3.4 SQE TEST .......................................................................................................................... 7

1.3.5 Natural Loopback ................................................................................................................ 7

1.3.6 Repeater Mode ................................................................................................................... 7

1.4

Auto-Negotiation

............................................................................................................................ 8

1.5

MediaIndependentInterface

......................................................................................................... 9

1.5.1 MII Transmit and Receive Operation................................................................................... 9

1.5.2 Station Management Interface ............................................................................................ 9

1.6

AdditionalFeatures

......................................................................................................................10

1.6.1 LED Indicators...................................................................................................................10

1.6.2 Interrupt Pin.......................................................................................................................10

1.6.3 Automatic MDI/ MDI-X Configuration ................................................................................10

2 Pin Description.....................................................................................................................................11

2.1

Legend

..........................................................................................................................................11

2.2

MII (Media Independent Interface)

..............................................................................................11

2.3

Control and Status

.......................................................................................................................12

2.4

MDI (Media Dependent Interface)

...............................................................................................12

2.5

Oscillator/Clock

............................................................................................................................12

2.6

Power Supply and Ground

...........................................................................................................12

2.7

LED Signals (Programmability Is Secondary Requirement)

......................................................13

3 Register Description...........................................................................................................................14

3.1

MR0: Control Register

.................................................................................................................15

3.2

MR1: Status Register

...................................................................................................................16

3.3

MR2: PHY Identifier Register 1

...................................................................................................17

3.4

MR3: PHY Identifier Register 2

...................................................................................................17

3.5

MR4: Auto-Negotiation Advertisement Register

.........................................................................17

3.6

MR5: Auto-Negotiation Link Partner Ability Register

................................................................18

3.7

MR6: Auto-Negotiation Expansion Register

...............................................................................18

3.8

MR16: Vendor Specific Register

.................................................................................................18

3.9

MR17: Interrupt Control/Status Register

.....................................................................................20

3.10

MR18: DiagnosticRegister

..........................................................................................................21

3.11

MR19: Transceiver Control

.........................................................................................................21

3.12

MR20:Reserved

..........................................................................................................................21

3.13

MR21:Reserved

..........................................................................................................................21

3.14

MR22:Reserved

..........................................................................................................................21

3.15

MR23: LED Configuration Register

.............................................................................................22

3.16

MR24: MDI/MDIX Control Register

.............................................................................................22

DS_21x3_001 78Q2123/78Q2133 Data Sheet

4 Electrical Specifications......................................................................................................................23

4.1

AbsoluteMaximum Ratings

.........................................................................................................23

4.2

RecommendedOperatingConditions

.........................................................................................23

4.3

DCCharacteristics

.......................................................................................................................23

4.4

Digital I/O Characteristics

............................................................................................................24

4.5

Digital Timing Characteristics

......................................................................................................25

4.5.2 MII Transmit Interface .......................................................................................................25

4.5.3 MII Receive Interface.........................................................................................................26

4.6

MDIO Interface Input Timing

........................................................................................................26

4.6.1 MDIO Interface Output Timing ..........................................................................................27

4.6.2 MDIO Interface Output Timing ..........................................................................................28

4.6.3 100BASE-TX System Timing ............................................................................................29

4.6.4 10BASE-T System Timing.................................................................................................29

4.7

Analog Electrical Characteristics

.................................................................................................30

4.7.1 100BASE-TX Transmitter..................................................................................................30

4.7.2 100BASE-TX Transmitter (Informative).............................................................................30

4.7.3 100BASE-TX Receiver......................................................................................................30

4.7.4 10BASE-T Transmitter ......................................................................................................31

4.7.5 10BASE-T Transmitter (Informative) .................................................................................31

4.7.6 10BASE-T Receiver ..........................................................................................................31

4.8

Isolation Transformers .................................................................................................................33

4.9

ReferenceCrystal

.........................................................................................................................33

4.9.1 External XTLP Oscillator Characteristics...........................................................................34

5 Package Pin Designations ..................................................................................................................35

6 Package Information............................................................................................................................36

7 Ordering Information...........................................................................................................................36

Revision History...........................................................................................................................................37

78Q2123/78Q2133 Data Sheet DS_21x3_001

Figures

Figure 1: RST Pulse Duration ...........................................................................................................................25

Figure 2: Transmit Inputs to the 78Q2123/78Q2133........................................................................................25

Figure 3: Receive Outputs from the 78Q2123/78Q2133 .................................................................................26

Figure 4: MDIO as an Input to the 78Q2123/78Q2133 ....................................................................................26

Figure 5: MDIO as an Output to the 78Q2123/78Q2133............................................................................. 27

Figure 6: MDIO Interface Output Timing...................................................................................................... 28

Figure 7: Application Diagram for 78Q2123/78Q2133 .....................................................................................32

Figure 8: External XTLP Oscillator Characteristics ...................................................................................... 34

Figure 9: Package Pin Designations.................................................................................................................35

DS_21x3_001 78Q2123/78Q2133 Data Sheet

1 Functional Description

1.1

General

1.1.1 Power Management

The 78Q2123 and 78Q2133 have three power saving modes:

xChip Power-Down

xReceive Power Management

xTransmit High Impedance Mode

Chip power-down is activated by setting the PWRDN bit in MII register MR0.11. When the chip is in

power-down mode, all on-chip circuitry is shut off, and the device consumes minimum power. While in

the power-down state, the 78Q2123/78Q2133 still respond to management transactions.

Receive power management (RXCC mode) is activated by setting the RXCC bit in MII register MR16.0.

In this mode of operation, the adaptive equalizer, the clock recovery phase lock loop (PLL), and all other

receive circuitry will be powered down when no valid MLT-3 signal is present at the UTP receive line

interface. As soon as a valid signal is detected, all circuits will automatically be powered up to resume

normal operation. During this mode of operation, RX_CLK will be inactive when there is no data being

received. Note that the RXCC mode is not supported during 10BASE-T operation.

Transmit high impedance mode is activated by setting the TXHIM bit in MII register MR16.12. In this

mode of operation, the transmit UTP drivers are in a high impedance state and TX_CLK is tri-stated. A

weak internal pull-up is enabled on TX_CLK. The receive circuitry remains fully operational. The default

state of MR16.12 is a logic low for disabling the transmit high impedance mode. Only a reset condition will

automatically clear MR16.12. The transmitter is fully functional when MR16.12 is cleared. This feature is

useful when configuring a system for Wake-On LAN (when the 78Q2123/78Q2133 are coupled with a

Wake-On LAN capable MAC).

1.1.2 Analog Biasing and Supply Regulation

The 78Q2123/78Q2133 require no external component to generate on-chip bias voltages and currents.

High accuracy is maintained through a closed-loop trimmed biasing network.

On-chip digital logic runs off an internal voltage regulator. Hence only a single 3.3V (r0.3V) supply is

required to power-up the device. The on-chip regulator is not affected by the power-down mode.

1.1.3 Clock Selection

The 78Q2123/78Q2133 have an on-chip crystal oscillator which can also be driven by an external oscillator.

In this mode of operation, a 25 MHz crystal should be connected between the XTLP and XTLN pins.

Alternatively, an external 25 MHz clock input can be connected to the XTLP pin. In this mode of operation,

a crystal is not required and the XTLN pin must be tied to ground.

1.1.4 Transmit Clock Generation

The transmitter uses an on-chip frequency synthesizer to generate the transmit clock. In 100BASE-TX

operation, the synthesizer multiplies the reference clock by 5 to obtain the internal 125 MHz serial transmit

clock. In 10BASE-T mode, it generates an internal 20MHz transmit clock by multiplying the reference

25 MHz clock by 4/5. The synthesizer references either the local 25 MHz crystal oscillator, or the externally

applied clock, depending on the selected mode of operation.

78Q2123/78Q2133 Data Sheet DS_21x3_001

1.1.5 Receive Signal Qualification

The integrated signal qualifier has separate squelch and unsquelch thresholds. It also includes a built-in timer

to ensure fast and accurate signal detection and line noise rejection. Upon detection of two or more valid

10BASE-T or 100BASE-TX pulses on the line receive port, signal detect is indicated. The signal detect

threshold is then lowered by about 40%. All adaptive circuits are released from their initial states and allowed

to lock onto the incoming data. In 100BASE-TX operation, signal detect is de-asserted when no signal is

presented for a period of about 1.2 μs. In 10BASE-T operation, signal detect is de-asserted whenever no

Manchester data is received. In either case, the signal detect threshold will return to the squelched level

whenever the signal detect indication is de-asserted. Signal detect is also used to control the operation of the

clock/data recovery circuit to assure fast acquisition.

1.1.6 Receive Clock Recovery

In 100BASE-TX mode, the 125 MHz receive clock is extracted using a digital DLL-based loop. When no

receive signal is present, the CDR is directed to lock onto the 125 MHz transmit serial clock. When signal

detect is asserted, the CDR will use the received MLT-3 signal as the clock reference. The recovered clock is

used to re-time the data signal and for conversion of the data to NRZ format.

In 10BASE-T mode, the 20 MHz receive clock is recovered digitally from the Manchester data using a

DLL locked to the reference clock. When Manchester-coded preambles are detected, the CDR

immediately re-aligns the phase of the clock to synchronize with the incoming data. Hence clock

acquisition is fast and immediate.

1.2

100BASE-TX OPERATION

1.2.1 100BASE-TX Transmit

The 78Q2123/78Q2133 contain all of the necessary circuitry to convert the transmit MII signaling from a

MAC to an IEEE-802.3 compliant data-stream driving Cat-5 UTP cabling. The internal PCS interface

maps 4 bit nibbles from the MII to 5 bit code groups as defined in Table 24-1 of IEEE-802.3. These 5 bit

code groups are then scrambled and converted to a serial stream before being sent to the MLT-3 pulse

shaping circuitry and line driver. The pulse-shaper uses current modulation to produce the desired output

waveform. Controlled rise/fall time in the MLT-3 signal is achieved using an accurately controlled voltage

ramp generator. The line driver requires an external 1:1 isolation transformer to interface with the line

media. The center-tap of the primary side of the transformer must be connected to the Vcc supply (3.3V

r0.3V).

1.2.2 100BASE-TX Receive

The 78Q2123/78Q2133 receive a 125MBaud MLT-3 signal through a 1:1 transformer. The signal then

goes through a combination of adaptive offset adjustment (baseline wander correction) and adaptive

equalization. The effect of these circuits is to sense the amount of dispersion and attenuation caused by

the cable and transformer, and restore the received pulses to logic levels. The amount of gain and

equalization applied to the pulses varies with the detected attenuation and dispersion and, therefore, with

the length of the cable. The 78Q2123/78Q2133 can compensate for cable loss of up to 10dB at 16 MHz.

This loss is represented as test_chan_5 in Annex A of the ANSI X3.263:199X. The equalized MLT-3 data

signal is bi-directionally sliced and the resulting NRZI bit-stream is presented to the CDR where it is

re-timed and decoded to NRZ format. The re-timed serial data passes through a serial-to-parallel

converter, then descrambled and aligned into 5 bit code groups. The receive PCS interface maps these

code groups to 4 bit data for the MII as outlined in Table 24-1 in Clause 24 of IEEE-802.3.

1.2.3 PCS Bypass Mode (Auto-negotiate must be off)

The PCS Bypass mode is entered by setting register bit MR 16.1. In this mode the 78Q2123/78Q2133

accept scrambled 5 bit code words at the TX_ER and TXD[3:0] pins, TX_ER being the MSB of the data

input. The 5 bit code groups are converted to MLT-3 signal for transmission.

DS_21x3_001 78Q2123/78Q2133 Data Sheet

The received MLT-3 signal is converted to 5 bit NRZ code groups and output from the RX_ER and

RXD[3:0] pins, RX_ER being the MSB of the data output. The RX_DV and TX_EN pins are unused in

PCS Bypass mode.

1.3

10BASE-T OPERATION

1.3.1 10BASE-T Transmit

The 78Q2123/78Q2133 take 4-bit parallel NRZ data via the MII interface and passes it through a parallel

to serial converter. The data is then passed through a Manchester encoder, pre-emphasis pulse-shaper,

media filter, and finally to the twisted-pair line driver. The pulse-shaper and filter ensure the output

waveforms meet the voltage template and spectral content requirements detailed in Clause 14 of

IEEE-802.3. Interface to the twisted-pair media is through a center-tapped 1:1 transformer. No external

filtering is required. During auto-negotiation and 10BASE-T idle periods, link pulses are transmitted.

The 78Q2123/78Q2133 employ an onboard timer to prevent the MAC from capturing a network through

excessively long transmissions. When this timer expires, the chip enters the jabber state and

transmission is halted. The jabber state is exited after the MII goes idle for 500r250 ms.

1.3.2 10BASE-T Receive

The 78Q2123/78Q2133 receive Manchester-encoded 10BASE-T data through the twisted pair inputs and

re-establishes logic levels through a slicer with a smart squelch function. The slicer automatically adjusts

its level after detection of valid data with the appropriate levels. Data is passed on to the CDR where the

clock is recovered, and the data is re-timed and decoded. From there, data enters the serial-to-parallel

converter for transmission to the MAC via the Media Independent Interface. Interface to the twisted-pair

media is through an external 1:1 transformer. Polarity information is detected and corrected within

internal circuitry.

1.3.3 Polarity Correction

The 78Q2123/78Q2133 are capable of either automatic or manual polarity reversal for 10BASE-T and

auto-negotiation functions. Register bits MR16.5 and MR16.4 control this feature. The default is

automatic mode where MR16.5 is low and MR16.4 indicates if the detection circuitry has inverted the

input signal. To enter manual mode, MR16.5 should be set high and MR16.4 will then control the signal

polarity.

1.3.4 SQE TEST

The 78Q2123/78Q2133 support the Signal Quality Error (SQE) function detailed in IEEE-802.3. At an

interval of 1Ps after each negative transition of the TX_EN pin in 10BASE-T mode, the COL pin will go

high for a period of 1 Ps. SQE is not signaled during transmission after collision is detected. SQE is

automatically disabled when repeater mode is enabled. This function can be disabled through register bit

MR16.11.

1.3.5 Natural Loopback

When enabled, whenever the 78Q2123/78Q2133 are transmitting and not receiving on the twisted pair

media (10BASE-T Half Duplex mode), data on the TXD3-0 pins are looped back onto the RXD3-0 pins.

During a collision, data from the RXI pins is routed to the RXD3-0 pins. The natural loopback function is

enabled through register bit MR16.10. This feature is off by default.

1.3.6 Repeater Mode

When register bit MR16.15 is set, the 78Q2123/78Q2133 are placed in repeater mode. In this mode, full

duplex operation is prohibited, CRS responds only to receive activity and, in 10BASE-T mode, the SQE

test function is disabled.

78Q2123/78Q2133 Data Sheet DS_21x3_001

1.4

Auto-Negotiation

The 78Q2123/78Q2133 support the auto-negotiation functions of Clause 28 of IEEE-802.3 for 10/100

Mbps operation over copper wiring. This function can be enabled via register settings. The

auto-negotiation function defaults to ON and bit MR0.12 (ANEGEN) is high after reset. Software can

disable the auto-negotiation function by writing to bit MR0.12.

The contents of register MR4 are sent to the 78Q2123/78Q2133’s link partner during auto-negotiation via

fast link pulse coding.

The default values of the auto-negotiation registers are set as follows:

0.13 Speed Select 1 (100 BASE TX)

0.12 AN Enable 1 (enabled)

0.8 Duplex 1 (full duplex)

4.8/1.14 100BASE-TX

Full Duplex

4.7/1.13 100 BASE-TX 1

4.6/1.12 10 BASE-T

Full Duplex

4.5/1.11 10 BASE-T 1

These default values can be changed by writing different values to the registers, then restarting

auto-negotiation.

With auto-negotiation enabled, the 78Q2123/78Q2133 will start sending fast link pulses at power on, loss

of link or upon a command to restart. At the same time, it will look for either 10BASE-T idle, 100BASE-TX

idle, or fast link pulses from its link partner. If either idle pattern is detected, the 78Q2123/78Q2133

configure themselves in half-duplex mode at the appropriate speed. If it detects fast link pulses, it

decodes and analyzes the link code transmitted by the link partner. When three identical link code words

are received (ignoring the acknowledge bit) the link code word is stored in register MR5. Upon receiving

three more identical link code words, with the acknowledge bit set, the 78Q2123/78Q2133 configure

themselves to the highest priority technology common to the two link partners. The technology priorities

are, in descending order:

100BASE-TX, Full Duplex

100BASE-TX, Half Duplex

10BASE-T, Full Duplex

10BASE-T, Half Duplex

Once auto-negotiation is complete, register bits MR18.11:10 will reflect the actual speed and duplex that

was chosen.

If auto-negotiation fails to establish a link for any reason, register bit MR18.12 will reflect this and auto

negotiation will restart from the beginning. Writing a ‘1’ to bit MR0.9 (RANEG) will also cause

auto-negotiation to restart.

DS_21x3_001 78Q2123/78Q2133 Data Sheet

1.5

MediaIndependentInterface

1.5.1 MII Transmit and Receive Operation

The MII interface on the 78Q2123/78Q2133 provide independent transmit and receive paths for both

10Mb/s and 100Mb/s data rates as described in Clause 22 of the IEEE-802.3 standard.

The transmit clock, TX_CLK, provides the timing reference for the transfer of TX_EN, TXD3-0, and

TX_ER signals from the MAC to the 78Q2123/78Q2133. TXD3-0 is captured on the rising edge of

TX_CLK when TX_EN is asserted. TX_ER is also captured on the rising edge of TX_CLK and is

asserted by the MAC to request that an error code group is to be transmitted. The assertion of TX_ER is

ignored when the 78Q2123/78Q2133 are operating in 10BASE-T mode.

The receive clock, RX_CLK, provides the timing reference to transfer RX_DV, RXD3-0, and RX_ER

signals from the 78Q2123/78Q2133 to the MAC. RX_DV transitions synchronously with respect to

RX_CLK and is asserted when the 78Q2123/78Q2133 are presenting valid data on RXD3-0. RX_ER is

asserted and is synchronous to RX_CLK when a code group violation has been detected in the current

receive packet.

1.5.2 Station Management Interface

The station management interface consists of circuitry which implements the serial protocol as described

in Clause 22.2.4.4 of IEEE-802.3. A 16-bit shift register receives serial data applied to the MDIO pin at

the rising-edge of the MDC clock signal. Once the preamble is received, the station management control

logic looks for the start-of-frame sequence and a read or write op-code, followed by the PHYAD and

REGAD fields. The default address for the 78Q2123/78Q2133 is 1. For a read operation, the MDIO port

becomes enabled as an output and the register data is loaded into a shift register for transmission. The

78Q2123/78Q2133 can work with a one-bit preamble rather than the 32 bits prescribed by IEEE-802.3.

This allows for faster programming of the registers. If a register does not exist at an address indicated by

the REGAD field or if the PHYAD field does not match the 78Q2123/78Q2133 PHYAD, a read of the

MDIO port will return all ones. For a write operation, the data is shifted in and loaded into the appropriate

78Q2123/78Q2133 are ignored.

When the PHYAD field is all zeros, the Station Management Entity (STA) is requesting a broadcast data

transaction. All PHYs sharing the same Management Interface must respond to this broadcast request.

The 78Q2123/78Q2133 will respond to the broadcast data transaction.

78Q2123/78Q2133 Data Sheet DS_21x3_001

1.6

AdditionalFeatures

1.6.1 LED Indicators

There are two LED pins that can be used to indicate various states of operation of the

78Q2123/78Q2133. The function of these pins is programmable via the MR23 register as shown in the

table below:

LEDState Indication

0 1 = Link OK (Default LED0)

1 1 = RX or TX Activity (Default LED1)

2 1 = TX Activity

3 1 = RX Activity

4 1 = Collision

5 1 = 100 BASE-TX mode

6 1 = 10 BASE-T mode

7 1 = Full Duplex

8 1= Link OK & Blink = RX or TX Activity

The default status of these LEDs are “Link OK” for LED0 and “RX or TX Activity” for LED1.

1.6.2 Interrupt Pin

The 78Q2123 and 78Q2133 have an Interrupt pin (INTR) that is asserted whenever any of the eight

interrupt bits of MR17.7:0 are set. These interrupt bits can be disabled via the MR17.15:8 Interrupt

Enable bits. The Interrupt Polarity bit, MR16.14, controls the active level of the INTR pin. When the INTR

pin is not asserted, the pin is held in a high impedance state. An external pull-up or pull-down resistor may

be required for use with the INTR pin.

1.6.3 Automatic MDI/ MDI-X Configuration

The 78Q2123 and 78Q2133 implement the automatic MDI/MDI-X configuration detailed in IEEE-802.3

2002. This function eliminates the need for cross over cables when connecting to another device. When

auto-switching is enabled, the 78Q2123/78Q2133 will attempt to detect activity on its given configuration.

If no activity is seen for 60 ms, the device will switch to the other configuration depending on a random

number sequence. The initial seed of the random number generator can be set via MR24.3:0. In

addition, the part includes an asynchronous MDIX reset that varies from 1.29 seconds to 1.57 seconds to

ensure lock step will not occur between two devices.

The 78Q2123 and 78Q2133 will also allow for auto-switching while the part is not in auto-negotiation

mode. The IEEE 802.3 specification will not work in this case if the other device is in auto-negotiation

mode. The 78Q2123 and 78Q2133 default to auto MDIX enabled with parallel detection. Register bits

MR24.6 and MR24.7 are both defaulted to 1. The 78Q2123 and 78Q2133 will resolve the proper

configuration within 5 seconds.

DS_21x3_001 78Q2123/78Q2133 Data Sheet

2 Pin Description

2.1

Legend

Type Description Type Description

A Analog Pin CI TTL-level Input

CIU TTL-level Input with Pull-up CIO TTL-compatible Bi-directional Pin

CIS TTL-level Input with Schmitt Trigger COZ Tristate-able CMOS Output

CO CMOS Output

S Supply G Ground

2.2

MII(MediaIndependentInterface)

Signal Pin Type Description

TX_CLK 15 COZ TRANSMIT CLOCK: TX_CLK is a continuous clock, which provides a

timing reference for the TX_EN, TX_ER and TXD[3:0] signals from the

MAC. The clock frequency is 25 MHz in 100BASE-TX mode and 2.5 MHz

in 10BASE-T mode. This pin is tri-stated in isolate mode and the TXHIM

mode.

TX_EN 16 CI TRANSMIT ENABLE: TX_EN is asserted by the MAC to indicate that

valid data for transmission is present on the TXD[3:0] pins.

TXD[3:0] [20:17] CI TRANSMIT DATA: TXD[3:0] receives data from the MAC for transmission

on a nibble basis. This data is captured on the rising edge of TX_CLK

when TX_EN is high.

TX_ER 14 CI TRANSMIT ERROR: TX_ER is asserted high by the MAC to request that

an error code-group be transmitted when TX_EN is high. In PCS bypass

mode, this pin becomes the MSB of the transmit 5-bit code group.

CRS 22 COZ CARRIER SENSE: When the 78Q2123/78Q2133 are not in repeater

mode, CRS is high whenever a non-idle condition exists on either the

transmitter or the receiver. In repeater mode, CRS is only active when a

non-idle condition exists on the receiver. This pin is tri-stated in isolate

mode.

COL 21 COZ COLLISION: COL is asserted high when a collision has been detected on

the media. In 10BASE-T mode COL is also used for the SQE test function.

This pin is tri-stated in isolate mode. During half duplex operation, the

rising edge of COL will occasionally occur upon the rising edge of

TX_CLK.

RX_CLK 12 COZ RECEIVE CLOCK: RX_CLK is a continuous clock, which provides a

timing reference to the MAC for the RX_DV, RX_ER and RXD[3:0] signals.

The clock frequency is 25 MHz in 100BASE-TX mode and 2.5 MHz in

10BASE-T mode. To reduce power consumption in 100BASE-TX mode,

the 78Q2123/78Q2133 provide an optional mode, enabled through

MR16.0, in which RX_CLK is held inactive (low) when no receive data is

detected. This pin is tri-stated in isolate mode.

RX_DV 11 COZ RECEIVE DATA VALID: RX_DV is asserted high to indicate that valid

data is present on the RXD[3:0] pins. In 100BASE-TX mode, it transitions

high with the first nibble of the preamble and is pulled low when the last

data nibble has been received. In 10BASE-T mode it transitions high when

the start-of-frame delimiter (SFD) is detected. This pin is tri-stated in

isolate mode.

78Q2123/78Q2133 Data Sheet DS_21x3_001

RXD[3:0] [5:8] COZ RECEIVE DATA: Received data is provided to the MAC via RXD[3:0].

These pins are tri-stated in isolate mode.

RX_ER 13 COZ RECEIVE ERROR: RX_ER is asserted high when an error is detected

during frame reception. In PCS bypass mode, this pin becomes the MSB of

the receive 5-bit code group. This pin is tri-stated in isolate mode.

MDC 2 CIS MANAGEMENT DATA CLOCK: MDC is the clock used for transferring

data via the MDIO pin.

MDIO 1 CIO MANAGEMENT DATA INPUT/OUTPUT: MDIO is a bi-directional port

used to access management registers within the 78Q2123/78Q2133. This

pin requires an external pull-up resistor as specified in IEEE-802.3.

2.3

Control and Status

Signal Pin Type Description

RST 23 CIS ACTIVE LOW RESET: When pulled low the pin resets the chip. The reset

pulse must be long enough to guarantee stabilization of the supply

voltage and startup of the oscillator. Refer to the Electrical Specifications

for the reset pulse requirements. There are two other ways to reset the

chip:

1. Through the internal power-on-reset (activated when the chip is

being powered up).

2. Through the MII register bit (MR 0.15).

INTR 32 COZ INTERRUPT PIN: This pin is used to signal an interrupt to the media

access controller. The pin is held in the high impedance state when an

interrupt is not indicated. The pin will be forced high or low to signal an

interrupt depending upon the value of the INPOL bit (MR16.14). The

events which trigger an interrupt can be programmed via the Interrupt

Control Register located at address MR17.

2.4

MDI(MediaDependent Interface)

Signal Pin Type Description

TXOP,

TXON

30,31 A TRANSMIT OUTPUT POSITIVE/NEGATIVE: Transmitter differential

outputs for both 10base-T and 100base-TX.

RXIP,

RXIN

28,27 A RECEIVE INPUT POSITIVE/NEGATIVE: Receiver differential inputs for

both 10BASE-T and 100BASE-TX.

2.5

Oscillator/Clock

Signal Pin Type Description

XTLP 24 A CRYSTAL INPUT: Should be connected to a 25 MHz crystal. If an

externally generated TTL compatibility clock signal is used, that signal is

applied here.

XTLN 25 A

CRYSTAL OUTPUT: Should be connected to a 25 MHz crystal. When an

external clock source is being used, this pin must be grounded.

2.6

Power Supply andGround

Signal Pin Type Description

PW R 9, 26 S +3.3VDC SUPPLY

GND 10, 29 G GROUND

DS_21x3_001 78Q2123/78Q2133 Data Sheet

2.7

LEDSignals(ProgrammabilityIsSecondaryRequirement)

Signal Pin Type Description

LED0 4 CO PROGRAMMABLE LED. Active low. Default status: LINK OK. Active to

indicate link with far end PHY.

LED1 3 CO PROGRAMMABLE LED. Active low. Default status: RX or TX ACTIVITY.

Active to indicate TX or RX activity on the MDI.

Other LED options selectable via MR23:

TRANSMIT: ON when there is a transmission (normally OFF).

RECEIVE: ON when there is a reception (normally OFF).

COLLISION: In half duplex mode, this is a collision indicator and turns-ON when

a collision occurs. In full duplex mode, this LED is held OFF.

BASE-TX: ON for 100BASE-TX connection and OFF for other

connections. LEDBTX is OFF during auto-negotiation.

BASE-T: ON for 10BASE-T connection and OFF for other connections.

LEDBT is OFF during auto-negotiation.

FULL DUPLEX: ON when in full duplex mode and OFF when in half

duplex mode.

LINK/ACT: ON for link, blink for activity.

78Q2123/78Q2133 Data Sheet DS_21x3_001

3 Register Description

The 78Q2123/78Q2133 implement 13 16-bit registers, which are accessible via the MDIO and MDC pins.

The supported registers are shown below in the following table. Attempts to read unsupported registers

will be ignored and the MDIO pin will not be enabled as an output, as per the IEEE 802.3 specification.

All of the registers except those that are unique to the 78Q2123/78Q2133 will respond to the broadcast

PHYAD value of ‘00000’. The registers specific to the 78Q2123/78Q2133 occupy address space

MR16-24.

Address Symbol Name Default (Hex)

0 MR0 Control (3100)

1 MR1 Status (7849)

2 MR2 PHY Identifier 1 000E

3 MR3 PHY Identifier 2 7237

4 MR4 Auto-Negotiation Advertisement (01E1)

5 MR5 Auto-Negotiation Link Partner Ability 0000

6 MR6 Auto-Negotiation Expansion 0000

7 MR7 Not Implemented 0000

8-14 MR8-14 Reserved 0000

15 MR15 Not Implemented 0000

16 MR16 Vendor Specific (0140)

17 MR17 Interrupt Control/Status Register 0000

18 MR18 Diagnostic Register 0000

19 MR19 Transceiver Control 4XXX

20-22 MR20-22 Reserved 0000

23 MR23 LED Configuration Register 0010

24 MR24 MDI/MDIX Control Register (00C0)

Legend

Type Description Type Description

R Readable by management. W Writeable by management.

WC Writeable by management. Self

Clearing.

RC Readable by management.

Cleared upon a read operation.

0/1 Default value upon power up or

reset.

DS_21x3_001 78Q2123/78Q2133 Data Sheet

3.1

MR0:ControlRegister

Bit Symbol Type Default Description

0.15 RESET R/WC 0 Reset: Setting this bit to ‘1’ resets the device and sets all

registers to their default states. This bit is self-clearing.

0.14 LOOPBK R/W 0 Loopback: When this bit is set to ‘1’, input data at TXD[3:0] is

output at RXD[3:0]. No transmission of data on the network

medium occurs and receive data on the network medium is

ignored. By default, the loopback signal path encompasses

most of the digital functional blocks. This bit allows for

diagnostic testing.

0.13 SPEEDSL R/W 1 Speed Selection: This bit determines the speed of operation

of the 78Q2123/78Q2133. Setting this bit to ‘1’ indicates

100Base-TX operation and a ‘0’ indicates 10Base-T mode.

This bit will default to a ‘1’ upon reset. When auto-negotiation

is enabled, this bit will not be writable and will have no effect

on the 78Q2123/78Q2133. If auto-negotiation is not enabled,

this bit may be written to force manual configuration.

0.12 ANEGEN R/W 1 Auto-Negotiation Enable: The auto-negotiation process is

enabled by setting this bit to ‘1’. This bit will default to ‘1’. If

this bit is cleared to ‘0’, manual speed and duplex mode

selection is accomplished through bits 0.13 (SPEEDSL) and

0.8 (DUPLEX) of the Control Register.

0.11 PWRDN R/W 0 Power-Down: The device may be placed in a low power

consumption state by setting this bit to ‘1’. While in the power-

down state, the device will still respond to management

transactions.

0.10 ISO R/W 0 Isolate: When set to ‘1’, the device will present a high-

impedance on its MII output pins. This allows for multiple

PHY’s to be attached to the same MII interface. When the

device is isolated, it still responds to management

transactions.

0.9 RANEG R/WC 0 Restart Auto-Negotiation: Normally, the Auto-Negotiation

process is started at power up. The process can be restarted

by setting this bit to ‘1’. This bit is self-clearing.

0.8 DUPLEX R/W 1 Duplex Mode: This bit determines whether the device

supports full- duplex or half-duplex. A ‘1’ indicates full-duplex

operation and a ‘0’ indicates half-duplex. This bit will default

to ‘1’ upon reset. When auto-negotiation is enabled, this bit

will not be writable and will have no effect on the

78Q2123/78Q2133. If auto-negotiation is not enabled, this bit

may be written to force manual configuration.

0.7 COLT R/W 0 Collision Test: When this bit is set to ‘1’, the device will assert

the COL signal in response to the assertion of the TX_EN

signal. Collision test is disabled if the PCSBP bit, MR16.1, is

high. Collision test can be activated regardless of the duplex

mode of operation.

0.6:0 RSVD R 0 Reserved

78Q2123/78Q2133 Data Sheet DS_21x3_001

3.2

MR1:StatusRegister

Bits 1.15 through 1.11 reflect the ability of the 78Q2123/78Q2133. They do not reflect any ability changes

made via the MII Management Interface to bits 0.13 (SPEEDSL) , 0.12 (ANEGEN) and 0.8 (DUPLEX)in

the Control Register.

Bit Symbol Type Default Description

1.15 100T4 R 0

100BASE-T4 Ability: Reads ‘0’ to indicate the

78Q2123/78Q2133 do not support 100Base-T4 mode.

1.14 100X_F R 1 100BASE-TX Full Duplex Ability:

0 : Not able

1 : Able

1.13 100X_H R 1 100BASE-TX Half Duplex Ability:

0 : Not able

1 : Able

1.12 10T_F R 1 10BASE-T Full Duplex Ability:

0 : Not able

1 : Able

1.11 10T_H R 1 10BASE-T Half Duplex Ability:

0 : Not able

1 : Able

1.10 100T2_F R 0

100BASE-T2 Full Duplex Ability: Reads ‘0’ to indicate the

78Q2123/78Q2133 do not support 100Base-T2 full duplex

mode.

1.9 100T2_H R 0

100BASE-T2 Half Duplex Ability: Reads ‘0’ to indicate the

78Q2123/78Q2133 do not support 100Base-T2 full duplex

mode.

1.8 EXTS R 0 Extended Status Information Availability: Reads ‘0’ to indicate

the 78Q2123/78Q2133 do not support Extended Status

information on MR15.

1.7 RSVD R 0 Reserved

1.6 MFPS R 0 Management Frame Preamble Suppression Support: A “0”

indicates that the 78Q2123/78Q2133 can read management

frames with a preamble.

1.5 ANEGC R 0 Auto-Negotiation Complete: A logic one indicates that the

Auto-Negotiation process has been completed, and that the

contents of registers MR4,5,6 are valid.

1.4 RFAULT RC 0 Remote Fault: A logic one indicates that a remote fault

condition has been detected and it remains set until it is

cleared. This bit can only be cleared by reading this register

(MR1) via the management interface.

1.3 ANEGA R (1) Auto-Negotiation Ability: When set, this bit indicates the

device’s ability to perform Auto-Negotiation. The value of this

bit is determined by the ANEGENbit (MR0.12).

1.2 LINK R 0 Link Status: A logic one indicates that a valid link has been

established. If the link status should transition from an OK

status to a NOT-OK status, this bit will become cleared and

remains cleared until it is read.

1.1 JAB RC 0 Jabber Detect: In 10Base-T mode, this bit is set during a

jabber event. After a jabber event, the bit remains set until

DS_21x3_001 78Q2123/78Q2133 Data Sheet

cleared by a read operation.

1.0 EXTD R 1 Extended Capability: Reads ’1’ to indicate the

78Q2123/78Q2133 provide an extended register set (MR2

and beyond).

3.3

MR2:PH Y Ide nt ifi er Re gis ter 1

Bit Symbol Type Value Description

2.15:0 OUI [23:6] R 000Eh Organizationally Unique Identifier: This value is 00-C0-39 for

Teridian Semiconductor Corporation. This register contains the

first 16-bits of the identifier.

3.4

MR3:PH Y Ide nt ifi er Re gis ter 2

Bit Symbol Type Value Description

3.15:10 OUI [5:0] R 1Ch Organizationally Unique Identifier: Remaining 6 bits of the

OUI.

3.9:4 MN R 23h Model Number: The last 2 digits of the model number

78Q2123 are encoded into the 6 bits for both 78Q2123 and

78Q2133.

3.3:0 RN R 07h Revision Number: The value ‘0111’ corresponds to the

seventh revision of the silicon.

3.5

MR4:Auto-NegotiationAdvertisementRegister

Bit Symbol Type Default Description

4.15 NP R 0 Next Page: Not supported. Reads logic zero.

4.14 RSVD R 0 Reserved

4.13 RF R/W 0 Remote Fault: Setting this bit to ‘1’ allows the device to

indicate to the link partner a Remote Fault Condition.

4.12 A7 R 0 Reserved.

4.11 A6 R/W 0 Asymmetric PAUSE Support Indication for Full Duplex Links.

Default is 0 indicating not supported. If the MAC supports

Asymmetric PAUSE, this bit can be written as 1. Writing to this

4.10 A5 R 0

PAUSE Support Indication for Full Duplex Links. Default is 0

indicating not supported. If the MAC supports PAUSE, this bit

can be written as 1. Writing to this register has no effect until

auto-negotiation is re-initiated

4.9 A4 R 0 100BASE-T4: The 78Q2123/78Q2133 do not support

100BASE-T4 operation.

4.8 A3 R/W (1) 100BASE-TX Full Duplex: If the MR1.14 bit is ‘1’, this bit will

be set to ‘1’ upon reset and will be writeable. Otherwise, this

bit cannot be set to ‘1’ by the management.

4.7 A2 R/W (1) 100BASE-TX: If the MR1.13 bit is ‘1’, this bit will be set to ‘1’

upon reset and will be writeable. Otherwise, this bit cannot be

set to ‘1’ by the management.

4.6 A1 R/W (1) 10BASE-T Full Duplex: If the MR1.12 bit is ‘1’, this bit will be

set to ‘1’ upon reset and will be writeable. Otherwise, this bit

cannot be set to ‘1’ by the management.

78Q2123/78Q2133 Data Sheet DS_21x3_001

4.5 A0 R/W (1) 10BASE-T: If the MR1.11 bit is ‘1’, this bit will be set to ‘1’

upon reset and will be writeable. Otherwise, this bit cannot be

set to ‘1’ by the management.

4.4:0 S4:0 R 01h Selector Field: Hard coded with the value of ‘00001’ for IEEE

802.3.

Note: Technology Ability Field: MR4.12:5 are the Technology Ability Field bits (A7:0). The default value

of this field is dependent upon the MR1.15:11 register bits. This field can be overwritten by management

to auto-negotiate to an alternate common technology. Writing to this register has no effect until

auto-negotiation is re-initiated.

3.6

MR5: Auto-Negotiation Link Partner Ability Register

Bit Symbol Type Default Description

5.15 NP R 0 Next Page: When ‘1’ is read, it indicates the link partner

wishes to engage in Next Page exchange.

5.14 ACK R 0

Acknowledge: When ‘1’ is read, it indicates the link partner has

successfully received at least 3 consecutive and consistent

FLP bursts.

5.13 RF R 0 Remote Fault: When ‘1’ is read, it indicates the link partner has

a fault.

5.12:5 A7:0 R 0 Technology Ability Field: This field contains the technology

ability of the link partner. The bit definition is the same as

MR4.12:5.

5.4:0 S4:0 R 00h Selector Field: This field contains the type of message sent by

the link partner. For an IEEE 802.3 compliant link partner, this

field should be ‘00001’.

3.7

MR6:Auto-NegotiationExpansionRegister

Bit Symbol Type Default Description

6.15:5 RSVD R 0 Reserved

6.4 PDF RC 0 Parallel Detection Fault: When ‘1’ is read, it indicates that

more than one technology has been detected during link up.

This bit is cleared when read.

6.3 LPNPA R 0

Link Partner Next Page Able: When ‘1’ is read, it indicates the

link partner supports the Next Page function.

6.2 NPA R 0 Next Page Able: Reads ‘0’ since the 78Q2123/78Q2133 do not

support Next Page function.

6.1 PRX RC 0 Page Received: Reads ‘1’ when a new link code word has

been received into the Auto-Negotiation Link Partner Ability

6.0 LPANEGA R 0 Link Partner Auto-Negotiation Able: When ‘1’ is read, it

indicates the link partner is able to participate in the Auto-

Negotiation function.

3.8

MR16:Vendor SpecificRegister

Bit Symbol Type Default Description

16.15 RPTR R/W (0) Repeater Mode: When set, the 78Q2123/78Q2133 are put

into Repeater mode of operation. In this mode, full duplex is

DS_21x3_001 78Q2123/78Q2133 Data Sheet

prohibited, CRS responds to receive activity only and, in

10Base-T mode, the SQE test function is disabled.

16.14 INPOL R/W 0 When this bit is ‘0’, the INTR pin is forced low to signal an

interrupt. Setting this bit to ‘1’ causes the INTR pin to be

forced high to signal an interrupt.

16.13 RSVD R 0 Reserved

16.12 TXHIM R/W 0 Transmitter High-Impedance Mode: When set, the

TXOP/TXON transmit pins and the TX_CLK pin are put into a

high-impedance state. The receive circuitry remains fully

functional.

16.11 SQEI R/W 0 SQE Test Inhibit: Setting this bit to ‘1’ disables 10Base-T

SQE testing. By default, this bit is ‘0’ and the SQE test is

performed by generating a COL pulse following the

completion of a packet transmission.

16.10 NL10 R/W 0 10Base-T Natural Loopback: Setting this bit to ‘1’ causes

transmit data received on the TXD0-3 pins to be automatically

looped back to the RXD0-3 pins when 10Base-T mode is

enabled.

16.9 RSVD R 0 Reserved

16.8 RSVD R 1 Reserved

16.7 RSVD R 0 Reserved

16.6 RSVD R 1 Reserved

16.5 APOL R/W 0 Auto Polarity: During auto-negotiation and 10BASE-T mode,

the 78Q2123/78Q2133 are able to automatically invert the

received signal due to a wrong polarity connection. It does so

by detecting the polarity of the link pulses. Setting this bit to

‘1’ disables this feature.

16.4 RVSPOL R/W 0 Reverse Polarity: The reverse polarity is detected either

through 8 inverted 10Base-T link pulses (NLP) or through one

burst of inverted clock pulses in the auto-negotiation link

pulses (FLP). When the reverse polarity is detected and if the

Auto Polarity feature is enabled, the 78Q2123/78Q2133 will

invert the receive data input and set this bit to ‘1’. If Auto

Polarity is disabled, then this bit is writeable. Writing a ‘1’ to

this bit forces the polarity of the receive signal to be reversed.

16.3:2 RSVD R/W 0h Reserved: Must set to ‘00’.

16.1 PCSBP R/W 0 PCS Bypass Mode: When set, the 100Base-TX PCS and

scrambling/ descrambling functions are bypassed. Scrambled

5-bit code groups for transmission are applied to the TX_ER,

TXD3-0 pins and received on the RX_ER, RXD3-0 pins. The

RX_DV and TX_EN signals are not valid in this mode.

PCSBP mode is valid only when 100Base-TX mode is

enabled and auto-negotiation is disabled.

16.0 RXCC R/W 0 Receive Clock Control: This function is valid only in 100Base-

TX mode. When set to ‘1’, the RX_CLK signal will be held low

when there is no data being received (to save power). The

RX_CLK signal will restart 1 clock cycle before the assertion

of RX_DV and will be shut off 64 clock cycles after RX_DV

goes low. RXCC is disabled when loopback mode is enabled

(MR0.14 is high). This bit should be kept at logic zero when

PCS Bypass mode is used.

78Q2123/78Q2133 Data Sheet DS_21x3_001

3.9

MR17:InterruptControl/StatusRegister

The Interrupt Control/Status Register provides the means for controlling and observing the events, which

trigger an interrupt on the INTR pin. This register can also be used in a polling mode via the MII Serial

Interface as a means to observe key events within the PHY via one register address. Bits 0 through 7 are

status bits, which are each set to logic one based upon an event. These bits are cleared after the register

is read. Bits 8 through 15 of this register, when set to logic one, enable their corresponding bit in the

lower byte to signal an interrupt on the INTR pin. The assertion level of this interrupt signal output on the

INTR pin can be set via the MR16.14 (INPOL) bit.

Bit Symbol Type Default Description

17.15 JABBER_IE R/W 0 Jabber Interrupt Enable

17.14 RXER_IE R/W 0 Receive Error Interrupt Enable

17.13 PRX_IE R/W 0 Page Received Interrupt Enable

17.12 PDF_IE R/W 0 Parallel Detect Fault Interrupt Enable

17.11 LP-ACK_IE R/W 0 Link Partner Acknowledge Interrupt Enable

17.10 LS-CHG_IE R/W 0 Link Status Change Interrupt Enable

17.9 RFAULT_IE R/W 0 Remote Fault Interrupt Enable

17.8 ANEG-

COMP_IE

R/W 0 Auto-Negotiation Complete Interrupt Enable

17.7 JAB_INT RC 0 Jabber Interrupt: This bit is set high when a Jabber

event is detected by the 10Base-T circuitry.

17.6 RXER_INT RC 0 Receive Error Interrupt: This bit is set high when the

RX_ER signal transitions high.

17.5 PRX_INT RC 0 Page Received Interrupt: This bit is set high when a new

page has been received from the link partner during

auto-negotiation.

17.4 PDF_INT RC 0 Parallel Detect Fault Interrupt: This bit is set high by the

auto-negotiation logic when a parallel detect fault

condition is indicated.

17.3 LP-ACK_INT RC 0 Link Partner Acknowledge Interrupt: This bit is set high

by the auto-negotiation logic when FLP bursts are

received with the acknowledge bit set.

17.2 LS-CHG_INT RC 0 Link Status Change Interrupt: This bit is set when the

link transitions from an OK status to a FAIL status.

17.1 RFAULT_INT RC 0 Remote Fault Interrupt: This bit is set when a remote

fault condition has been indicated by the link partner.

17.0 ANEG-

COMP_INT

RC 0 Auto-Negotiation Complete Interrupt: This bit is set by

the auto-negotiation logic upon successful completion of

auto-negotiation.

DS_21x3_001 78Q2123/78Q2133 Data Sheet

3.10

MR18:DiagnosticRegister

Bit Symbol Type Default Description

18.15:13 RSVD R 0 Reserved

18.12 ANEGF RC 0 Auto-Negotiation Fail Indication: This bit is set when

auto-negotiation completes and no common technology was

found. It remains set until read.

18.11 DPLX R 0

Duplex Indication: This bit indicates the result of the

auto-negotiation for duplex arbitration as follows:

0 = Half-duplex was the highest common denominator

1 = Full-duplex was the highest common denominator

18.10 RATE R 0

Rate Indication: This bit indicates the result of the auto-

negotiation for data rate arbitration as follows:

0 = 10Base-T was the highest common denominator

1 = 100Base-TX was the highest common denominator

18.9 RXSD R 0 Receiver Signal Detect Indication: In 10Base-T mode, this

bit indicates that Manchester data has been detected. In

100Base-TX mode, it indicates that the receive signal

activity has been detected (but not necessarily locked on

to).

18.8 RX_LOCK R 0 Receive PLL Lock Indication: Indicates that the Receive

PLL has locked onto the receive signal for the selected

speed of operation (10Base-T or 100Base-TX).

18.7:0 RSVD R 00h Reserved: Must set to ‘00h’.

3.11

MR19: Transceiver Control

Bit Symbol Type Default Description

19.15:14 TXO[1:0] R/W 01 Transmit Amplitude Selection: Sets the transmit output

amplitude to account for transmit transformer insertion loss.

00 = Gain set for 0.0dB of insertion loss.

01 = Gain set for 0.4dB of insertion loss.

10 = Gain set for 0.8dB of insertion loss.

11 = Gain set for 1.2dB of insertion loss.

19.13:0 RSVD R XXXh Reserved

3.12

MR20:Reserved

Bit Symbol Type Default Description

20.15:0 Reserved NA XXXXh Reserved: must be 0000h.

3.13

MR21:Reserved

Bit Symbol Type Default Description

21.15:0 Reserved NA XXXXh Reserved: must be 0000h.

3.14

MR22:Reserved

Bit Symbol Type Default Description

22.15:0 Reserved NA XXXXh Reserved: must be 0000h.

78Q2123/78Q2133 Data Sheet DS_21x3_001

3.15

MR23:LEDConfigurationRegister

Bit Symbol Type Default Description

23.15:8 Reserved NA <0000> Must set to zero on each write to MR23

23.7:4 LED1[3:0] R/W <1h> 0000 = Link OK

0001 = RX or TX Activity (Default LED1)

0010 = TX Activity

0011 = RX Activity

0100 = Collision

0101 = 100 BASE-TX mode

0110 = 10 BASE-T mode

0111 = Full Duplex

1000 = Link OK/Blink=RX or TX Activity

23.3:0 LED0[3:0] R/W <0h> 0000 = Link OK (Default LED0)

0001 = RX or TX Activity

0010 = TX Activity

0011 = RX Activity

0100 = Collision

0101 = 100 BASE-TX mode

0110 = 10 BASE-T mode

0111 = Full Duplex

1000 = Link OK/Blink=RX or TX Activity

3.16

MR24:MDI/MDIXControlRegister

Bit Symbol Type Default Description

24.15:8 Reserved R 0 Reserved

24.7 PD_MODE R/W 1 Write a ‘1’ to this bit to add Parallel Detect mode. This

will allow auto-switching to work when auto-negotiation is

off while the other device has it on.

24.6 AUTO_SW R/W 1 Write a ‘1’ to this bit to enable auto switching.

24.5 MDIX R/W 0 Indicates state of the MDI pair or force configuration:

1 = MDIX (cross over)

0 = MDI

When auto_sw is a ‘1’, this bit will only be readable.

When auto_sw is a ‘0’ this bit can be written to set the

configuration.

24.4 MDIX_CM R 0 Indicates completion of auto-switch sequence.

1 = Sequence completed.

0 = Sequence in progress or auto-switch is disabled.

24.3:0 MDIX_SD R/W <0000> Write initial pattern seed for switching algorithm. The

initial seed directly affects attempts [5,4] respectively to

write bits [3:0]. Setting to [0000] will result in device

using its own seed of [0101].

DS_21x3_001 78Q2123/78Q2133 Data Sheet

4 Electrical Specifications

4.1

AbsoluteMaximumRatings

Operation above maximum rating may permanently damage the device.

Parameter Rating

DC Supply Voltage (Vcc) -0.5 to 4.0 VDC

Storage Temperature -65 to 150 qC

Pin Voltage (except TXOP/N) -0.3 to (Vcc+0.6) VDC

Pin Voltage (TXOP/N only) -0.3 to (Vcc+1.4) VDC

Pin Current r120 mA

4.2

RecommendedOperatingConditions

Unless otherwise noted, all specifications are valid over these temperatures and supply voltage ranges.

Parameter Rating

DC Voltage Supply (Vcc) 3.3 r0.3 VDC

78Q2123 Ambient Operating Temperature (Ta) 0 to 70 qC

78Q2133 Ambient Operating Temperature (Ta) -40 to 85 qC

Maximum Junction Temperature 125 qC

Package Thermal Conductivity (Tja) 50 qC/W

4.3

DCCharacteristics

Parameter Symbol Conditions Min Nom Max Unit

Supply Current

Vcc = 3.3V;

Auto-Negotiation

10BT (Idle)

10BT (Normal Activity)

100BTX

110

Supply Current

Power-down mode 6 mA

78Q2123/78Q2133 Data Sheet DS_21x3_001

4.4

DigitalI/OCharacteristics

Pi ns of ty pe CI, CIU, CID, CIO

Parameter Symbol Conditions Min Nom Max Unit

Input Voltage Low Vil

0.8 V

Input Voltage High Vih 2.0 3.6 V

Input Current Iil, Iih -1 1 PA

Pull-up Resistance Rpu Type CIU only 38 56 78 k:

Input Capacitance Cin

8 pF

Pi ns of type CI S

Parameter Symbol Conditions Min Nom Max Unit

Low-to-High Threshold Vt+

2.0 V

High-to-Low Threshold Vt- 0.8 V

Input Current Iil, Iih -1 1 PA

Input Capacitance Cin

8 pF

Input Hysteresis Vhy 125 mV

Pi ns of type CO Z

Parameter Symbol Conditions Min Nom Max Unit

Output Voltage Low Vol Iol = 4mA 0.4 V

Output Voltage High Voh Ioh = -4mA 2.4 V

Output Transition Time Tt CL = 20pF 6 ns

Tristate Output

Leakage Current

Iz -1 1 PA

Pi ns of ty pe CO

Parameter Symbol Conditions Min Nom Max Unit

Output Voltage Low Vol Iol = 4mA 0.4 V

Output Voltage High Voh Ioh = -4mA 2.4 V

Output Transition Time Tt CL = 20pF 6 ns

Pi ns of ty pe CIO

Parameter Symbol Conditions Min Nom Max Unit

Output Voltage Low Vol Iol = 4mA 0.4 V

Output Voltage High Voh Ioh = -4mA 2.4 V

Output Transition Time Tt CL = 20pF 6 ns

DS_21x3_001 78Q2123/78Q2133 Data Sheet

4.5

DigitalTimingCharacteristics

4.5.1 RST Characteristics

Figure 1: RST Pulse Duration

Parameter Symbol Conditions Min Nom Max Unit

RST Pulse Assertion Treset VCC = 3.3V and

oscillator stabilized

30 Oscillator

Clock

Cycles

4.5.2 MII Transmit Interface

Characteristics Symbol Conditions Min Nom Max Unit

Setup Time: TX_CLK to

TXD[3:0], TX_EN, TX_ER

TXSU 15 ns

Hold Time: TX_CLK to

TXD[3:0], TX_EN, TX_ER

TXHD 0 ns

CKIN-to-TX_CLK Delay TCKIN 0 40 ns

TX_CLK Duty-Cycle 40 60 %

Figure 2: Transmit Inputs to the 78Q2123/78Q2133

VCC

Oscillator

RST

Treset

78Q2123/78Q2133 Data Sheet DS_21x3_001

4.5.3 MII Receive Interface

Characteristics Symbol Conditions Min Nom Max Unit

Receive Output Delay:

RX_CLK to RXD[3:0],

RX_DV, RX_ER

RXDLY 10 30 ns

RX_CLK Duty-Cycle 40 60 %

Figure 3: Receive Outputs from the 78Q2123/78Q2133

4.6

MDIO Interface Input Timing

Characteristics Symbol Conditions Min Nom Max Unit

Setup Time: MDC to MDIO MIOSU 10 ns

Hold Time: MDC to MDIO MIOHD 10 ns

Max Frequency: MDC Fmax

25 MHz

Figure 4: MDIO as an Input to the 78Q2123/78Q2133

DS_21x3_001 78Q2123/78Q2133 Data Sheet

4.6.1 MDIO Interface Output Timing

Characteristics Symbol Conditions Min Nom Max Unit

MDC to MDIO data delay MC2D

30 ns

MDIO output from high Z

to driven after MDC

MCZ2D

30 ns

MDIO output from driven

to high Z after MDC

MCD2Z

30 ns

Figure 5: MDIO as an Output to the 78Q2123/78Q2133

78Q2123/78Q2133 Data Sheet DS_21x3_001

4.6.2 MDIO Interface Output Timing

Figure 6: MDIO Interface Output Timing

DS_21x3_001 78Q2123/78Q2133 Data Sheet

4.6.3 100BASE-TX System Timing

System timing requirements for 100BASE-TX operation are listed in Table 24-2 of Clause 24 of IEEE

802.3.

Parameter Condition Nom Unit

TX_EN Sampled to first bit of “J” on MDI

output

12 BT

First bit of “J” on MDI input to CRS assert 16 BT

First bit of “T” on MDI input to CRS

de-assert

23 BT

First bit of “J” on MDI input to COL assert 20 BT

First bit of “T” on MDI input to COL

de-assert

24 BT

TX_EN Sampled to CRS assert RPTR = low 6 BT

TX_EN sampled to CRS de-assert RPTR = low 6 BT

4.6.4 10BASE-T System Timing

Parameter Condition Min Nom Max Unit

TX_EN (MII) to TD Delay

6 BT

RD to RXD at (MII) Delay

6 BT

Collision delay

9 BT

SQE test wait

1 Ps

SQE test duration

1 Ps

Jabber on-time* 20 150 ms

Jabber off-time* 250 750 ms

* Guarantee by design. The specifications in the following table are included for information only.

78Q2123/78Q2133 Data Sheet DS_21x3_001

4.7

AnalogElectricalCharacteristics

4.7.1 100BASE-TX Transmitter

Parameter Condition Min Nom Max Unit

Peak Output Amplitude

(|Vp+|, |Vp-|)

(see note below)

Best-fit over 14 bit times;

0.4 dB Transformer loss

950 1050 mVpk

Output Amplitude

Symmetry

|Vp +|

|Vp -|

0.98 1.02

Output Overshoot Percent of Vp+, Vp- 5 %

Rise/Fall time (tr, tf) 10-90% of Vp+, Vp- 3 5 ns

Rise/Fall time Imbalance |tr - tf| 500 ps

Duty Cycle Distortion Deviation from best-fit time-

grid;

010101... Sequence

r250 ps

Jitter Scrambled Idle 1.4 ns

Note: Measured at the line side of the transformer.

Test Condition: Transformer P/N: TLA-6T103

Line Termination: 100 :±1%

4.7.2 100BASE-TX Transmitter (Informative)

The specifications in the following table are included for information only. They are mainly a function of

the external transformer and termination resistors used for measurements.

Parameter Condition Min Max Unit

Return Loss 2 < f < 30 MHz

30 < f < 60 MHz

60 < f < 80 MHz

1620 log§f ·

¨¸

©30MHz¹

Open-Circuit Inductance -8 < Iin < 8 mA 350 PH

4.7.3 100BASE-TX Receiver

Parameter Condition Min Nom Max Unit

Signal Detect Assertion

Threshold

500 600 700 mVppd

Signal Detect De-assertion

Threshold

275 350 425 mVppd

Differential Input Resistance

20 k:

Jitter Tolerance (pk-pk) Not tested in production 4 ns

Baseline Wander Tracking -75 +75 %

Signal Detect Assertion Time Not tested

1000 Ps

Signal Detect De-assertion

Time

Not tested 4 Ps

DS_21x3_001 78Q2123/78Q2133 Data Sheet

4.7.4 10BASE-T Transmitter

The Manchester-encoded data pulses, the link pulse and the start-of-idle pulse are tested against the

templates and using the procedures found in Clause 14 of IEEE 802.3.

Parameter Condition Min Nom Max Unit

Peak Differential Output Signal

(see note below)

All data patterns 2.2 2.8 V

Harmonic Content

(dB below fundamental)

Any harmonic

All ones data

Not tested

27 dB

Link Pulse Width

100 ns

Start-of-Idle Pulse Width Last bit 0

Last bit 1

300

350

Note: Measured at the line side of the transformer.

Test Condition: Transformer P/N: TLA-6T103

Line Termination: 100:±1%

4.7.5 10BASE-T Transmitter (Informative)

The specifications in the following table are included for information only. They are mainly a function of

the external transformer and termination resistors used for measurements.

Parameter Condition Min Nom Max Unit

Output return loss 15 dB

Output Impedance Balance 1 MHz < freq < 20 MHz



17log

§



¨ ¸



©



Peak Common-mode Output

Voltage

50 mV

Common-mode rejection 15 Vpk, 10.1 MHz sine wave

applied to transmitter

common-mode. All data

sequences.

100 mV

Common-mode rejection jitter 15 Vpk, 10.1 MHz sine wave

applied to transmitter

common-mode. All data

sequences.

1ns

4.7.6 10BASE-T Receiver

Parameter Condition Min Nom Max Unit

DLL Phase Acquisition Time

10 BT

Jitter Tolerance (pk-pk) 30 ns

Input Squelched Threshold 500 600 700 mVppd

Input Unsquelched Threshold 275 350 425 mVppd

Differential Input Resistance

20 k:

Bit Error Ratio

10-10

Common-mode rejection Square wave

0 < f < 500 kHz

Not tested

25 V

CCD

78Q2123/78Q2133 Data Sheet DS_21x3_001

100

100 VCC

5.1K

LED 1 D1

LED 0 D2

VCC

680

VCC

INTR

0.1uF

49.9

VCC

MDIO

MDC

RXD3

RXD2

RXD1

RXD0

RXDV

R11

100

0.1uF

R10

100

10 V

11 GN

RX_D

78Q2123

78Q2133

PB_GND 32

INTR 31

TXON 30

TXOP

0.01uF

2 TD+

TDCT

0.1uF

TX+ 15

TXCT

RJ45

RXCLK

RXER

TXER

TXCLK

TXEN

TXD0

TXD1 R12 R13

12 RX_CLK

13 RX_ER

14 TX_ER

16 TX_CLK

TX_EN

78Q2123

GND 29

RXIP 27

RXIN 26

VCC 25

XTLN

4 TD-

5 NC1

6 NC2

7 RD+

8 RDCT

RD-

14 5

TX- 13 4

NC4 12 3

NC3 11 2

RX+ 10 1

RXCT

RX-

TXD2

TXD3

COL

CRS

100 100

25.000MHz

TLA-6T118LF

VCC

R14

R15 C11 C12 R16 R17 R18 R19 R20 R21 C10

C13

C14 49.9 49.9

0.01UF 0.1UF

75 75 75 75 75 75 0.1uF

1.5kV

R22

100

R23

100

VCC

R24

10k

C15

0.1uF

27pF 27pF

C13 and C14 must be calibrated

in actual application board f or

25.000MHz +/-50ppm.

Figure 7: Application Diagram for 78Q2123/78Q2133

Rev. 1.6

TXD0

TXD1

TXD2

TXD3

COL

CRS

RST

XTLP

RXD0

RXD1

RXD2

RXD3

LED0

LED1

MDC

MDIO

10 9

DS_21x3_001 78Q2123/78Q2133 Data Sheet

4.8

Isolation Transformers

Two simple 1:1 isolation transformers are required at the line interface. Transformers with integrated

common-mode chokes are recommended for exceeding FCC requirements. This table gives the

recommended line transformer characteristics.

Name Value Condition

Turns Ratio 1 CT : 1 CT r5%

Open-Circuit Inductance 350 PH (min) @ 10 mV, 10 kHz

Leakage Inductance 0.40 PH (max) @ 1 MHz (min)

Inter-Winding Capacitance 25 pF (max)

D.C. Resistance 0.9 :(max)

Insertion Loss 0.4 dB (typ) 0 - 65 MHz

HIPOT 1500 Vrms

Note: The 100Base-TX amplitude specifications assume a transformer loss of 0.4 dB. For the transmit

line transformer with higher insertion losses, up to 1.2 dB of insertion loss can be compensated by

selecting the appropriate setting in the Transmit Amplitude Selection bits in register MR19.15:14.

4.9

ReferenceCrystal

If the internal crystal oscillator is to be used, a crystal with the following characteristics should be chosen.

Name Value Units

Frequency 25.00000 MHz

Load Capacitance* 4** pF

Frequency Tolerance r50 PPM

Aging r2 PPM/yr

Temperature Stability ( 0 - 70oC) r5 PPM

Oscillation Mode Parallel Resonance, Fundamental Mode

Parameters at 25oC r2oC ; Drive Level = 0.5 mW

Drive Level (typ) 50-100 PW

Shunt Capacitance (max) 10 pF

Motional Capacitance (min) 10 pF

Series Resistance (max) 60 :

Spurious Response (max) > 5 dB below main within 500 kHz

* Equivalent differential capacitance across the XTLP/XTLN pins.

** If crystal with a larger load is used, external shunt capacitors to ground should be added to make up

the equivalent capacitance difference.

78Q2123/78Q2133 Data Sheet DS_21x3_001

Tclkper

Tclkhi

Figure 8: External XTLP Oscillator Characteristics

4.9.1 External XTLP Oscillator Characteristics

Parameter Symbol Condition Min Nom Max Unit

XTLP Input Level See specification for

CIS-type input

XTLN Input Low

Voltage

0.8 V

XTLP Frequency f See Note 1 25.000 MHz

XTLP Period Tclkper See Note 1 40 ns

XTLP Duty Cycle Tclkhi / Tclkper 40 60 %

Rise / Fall Time Tr, Tf

4.0 ns

Absolute Jitter Input signaling

requirements = CIS

0.1 ns

Note 1: IEEE 802.3 frequency tolerance r50 ppm.

XTLP

DS_21x3_001 78Q2123/78Q2133 Data Sheet

5 Package Pin Designations

(Top View)

MDIO

MDC

LED1

LED0

RXD3

RXD2

RXD1

RXD0

XTLP

RST

CRS

COL

TXD3

TXD2

TXD1

TXD0

Note: For information only, actual package outline will vary depending on package type.

Figure 9: Package Pin Designations

1 24

2 23

3 22

4 TERIDIAN 21

78Q2123

5 20

78Q2133

6 19

7 18

8 17

PWR 932INTR

GND 10 31 TXON

RX_DV 11 30 TXOP

RX_CLK 12 29 GND

RX_ER 13 28 RXIP

TX_ER 14 27 RXIN

TX_CLK 15 26 PWR

TX_EN 25 XTLN

78Q2123/78Q2133 Data Sheet DS_21x3_001

6 Package Information

PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.

32-QFN G3255+3 21-0697 90-0434

32-TQFN T3255+4 21-0140 90-0012

7 Ordering Information

Part Package Option Ordering Number IC Marking

78Q2123,

Lead-Free,

Commercial

Temp

32-QFN

Bulk 78Q2123/F

Tape & Reel 78Q2123R/F

32-TQFN

Bulk 78Q2123S/F

Tape & Reel 78Q2123SR/F

78Q2133,

Lead-Free,

Industrial Temp

32-QFN Bulk 78Q2133/F

Tape & Reel 78Q2133R/F

32-TQFN

Bulk 78Q2133S/F

Tape & Reel 78Q2133SR/F

YY: Last two digits of year of assembly

WW: Week of assembly

RRRR:Die Rev Code from Reliability Database

###: Will be substituted with the last 3 numeric characters from the lot number

@@: Will be substituted with the first two alpha characters after the numeric characters from the lot

number

DS_21x3_001 78Q2123/78Q2133 Data Sheet

Revision History

Rev. # Date Comments

1.0 9/15/2005 First publication.

1.6 4/16/2010 Removed the 32-pin TQFP option.

2.0 9/24/2014 Added 32-TQFN package.

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses

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