am53c94 Advanced Micro Devices, am53c94 Datasheet - Page 15

• Manufacturer Part Number: am53c94
• Description: High Performance Scsi Controller
• Manufacturer: Advanced Micro Devices

SD
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.
SDC
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.
P
P
P R E L I M I N A R Y
Am53C94/Am53C96
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)
This is a SCSI input signal with a Schmitt trigger.
SEL
Select
(Input, Active Low, Schmitt Trigger)
This is a SCSI input signal with a Schmitt trigger.
RST
Reset
(Input, Active Low, Schmitt Trigger)
This is a SCSI input signal with a Schmitt trigger.
REQ
Request
(Input, Active Low, Schmitt Trigger)
This is a SCSI input signal with a Schmitt trigger.
ACK
Acknowledge
(Input, Active Low, Schmitt Trigger)
This is a SCSI input signal with a Schmitt trigger.
BSYC
Busy Control
(Output, Active Low, Open Drain)
This is a SCSI output with 48 mA drive. When the device
is configured in the Single Ended SCSI Mode (DFMODE
inactive) this pin is defined as a BSY output for the SCSI
bus. When the device is configured 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 out-
put to the SCSI bus and a low state corresponds to an
input from the SCSI bus.
AMD
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