DP83924 datasheet(6/42 Pages) NSC

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1.0 Pin Information (Continued)

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MDIO

LINK_4

I/O

Management Data I/O: When management interface is enabled (strap option,

COL[2]=1), this Bidirectional signal transfers data on the management interface be-

tween the controller and the transceiver.

Link Lost Status Port 4: When “Disable Management Interface” mode is selected,

(strap option, COL[2]=0), this pin outputs the link lost status for port 4. If link is lost, this

output is high.

INT

LINK_3

Interrupt: When “Enable Management Interface” mode is selected (strap option,

COL[2]=1), this output pin is driven low when an interrupt condition is detected within

the Quad Transceiver. An interrupt can occur when link status changes or during jabber

condition. This is an open-drain output. And requires an external pull-up resistor.

Link Lost Status Port 3: When “Disable Management Interface” mode is selected,

(strap option, COL[2]=0), this pin outputs the link lost status for port 3. If link is lost, this

output is high.

LINK_2

LINK_1

O, pull-up

Link Lost Status Ports 1,2: These pins indicate the link lost status for ports 1 and 2.

(During both management interface disable and enable modes)

LINK_1 is also the strap option for RXD levels during idle . S ee Table7 on page11. A

2.7 k

Ω pulldown resistor is needed to set RXD_IDLE = High. Default is LINK_1=’1’ and

RXD_IDLE= Low

Table 1. NRZ CONTROLLER INTERFACE and MANAGEMENT INTERFACE.

These pins provide the interface signalling between the Media Access Controller and the transceiver. (30 Pins)

Symbol

Pin #

Type

Description

Table 2. NETWORK INTERFACES: Attachment Unit, Twisted Pair Interface (24 Pins)

Symbol

Pins

Type

Description

RXI4+

RXI4-

RXI3+

RXI3-

RXI2+

RXI2-

RXI1+

RXI1-

Twisted Pair Receive Input: This differential input pair receives the incoming data from

the twisted pair medium via an isolation transformer.

TXU4+

TXU4-

TXU3+

TXU3-

TXU2+

TXU2-

TXU1+

TXU1-

UTP Transmit Outputs: This pair of drivers provide pre-emphasized and filtered differ-

ential output for UTP (100 ohm cable). These drivers maintain the same common mode

voltage during data transmission and idle mode.

Reserved

Reserved: This pin must be left unconnected.

ROC

On Chip Reference: An external resistor connects to ground for an on chip reference.

The resistor must be a precision (1%) resistor, the value of which should be determined

by each user to center VOD around 5 Vpp.

Attachment Unit Interface

RX+

RX-

Port 1 Full AUI Receive Input: In AUI mode this differential input pair receives the in-

coming data from the AUI medium via an isolation transformer.

TX+

TX-

Port 1 Full AUI Transmit Output: In AUI mode this differential pair sends encoded data

from the AUI transceiver. These outputs are source followers and require 270 Ohm pull

down resistors.

CD+

CD-

Port 1 Full AUI Collision Detect : In AUI mode, this differential input pair receives the

collision detect signals from the AUI medium via an isolation transformer.

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