AM53C94 datasheet(15/63 Pages) AMD

15 / 63 page

P R E L I M I N A R Y

AMD

Am53C94/Am53C96

SDP

SCSI Data Parity

(Input/Output, Active Low, Schmitt Trigger)

When the device is configured in the Single Ended SCSI

Mode (

DFMODE inactive) this pin is defined as the input

for the SCSI data parity. When the device is configured

in the Differential SCSI Mode (

DFMODE active) this pin

is defined as bidirectional SCSI data parity.

SDC 7–0

SCSI Data Control

(Output, Active Low, Open Drain)

When the device is configured in the Single Ended SCSI

Mode (

DFMODE inactive) these pins are defined as out-

puts for the SCSI data bus. When the device is config-

ured in the Differential SCSI Mode (

DFMODE active)

these pins are defined as direction controls for the exter-

nal differential transceivers. In this mode, a signal high

state corresponds to an output to the SCSI bus and a

low state corresponds to an input from the SCSI bus.

SDCP

SCSI Data Control Parity

(Output, Active Low, Open Drain)

When the device is configured in the Single Ended SCSI

Mode (

DFMODE inactive) this pin is defined as an out-

put for the SCSI data parity. When the device is config-

ured in the Differential SCSI Mode (

DFMODE active)

this pin is defined as the direction control for the external

differential transceiver. In this mode, a signal high state

corresponds to an output to the SCSI bus and a low

state corresponds to an input from the SCSI bus.

MSG

Message

(Input/Output, Active Low, Schmitt Trigger)

This is a bidirectional signal with 48 mA output driver. It

is an output in the target mode and a Schmitt trigger in-

put in the initiator mode.

C/D

Command/Data

(Input/Output, Schmitt Trigger)

This is a bidirectional signal with 48 mA output driver. It

is an output in the target mode and a Schmitt trigger in-

put in the initiator mode.

I/O

Input/Output

(Input/Output, Schmitt Trigger)

This is a bidirectional signal with 48 mA output driver. It

is an output in the target mode and a Schmitt trigger in-

put in the initiator mode.

ATN

Attention

(Input/Output, Active Low, Schmitt Trigger)

This signal is a 48 mA output in the initiator mode and a

Schmitt trigger input in the target mode. This signal will

be asserted when the initiator detects a parity error or it

can be asserted via certain initiator commands.

BSY

Busy

(Input, Active Low, Schmitt Trigger)