6 interrupt signals, Table 3.7 interrupt signals, Interrupt signals – Avago Technologies LSI53C896 User Manual
Page 98
3-10
Signal Descriptions
Version 3.3
Copyright © 1998–2003 by LSI Logic Corporation. All rights reserved.
3.2.6 Interrupt Signals
describes the Interrupt Signals group.
Table 3.7
Interrupt Signals
Name
1
Bump
Type
Strength
Description
INTA/
F4
O
16 mA
PCI
Interrupt Function A. This signal, when asserted LOW,
indicates an interrupting condition in SCSI Function A and
that service is required from the host CPU. The output drive
of this pin is open drain. If the SCSI Function B interrupt is
rerouted at power-up using the INTA/ enable sense resistor
(pull-up on MAD[4]), this signal indicates that an interrupting
condition has occurred in either the SCSI Function A or
SCSI Function B. This interrupt pin is disabled if INT_DIR
is driven LOW.
INTB/
F2
O
16 mA
PCI
Interrupt Function B. This signal, when asserted LOW,
indicates an interrupting condition has occurred in the SCSI
Function B and that service is required from the host CPU.
The output drive of this pin is open drain. This interrupt can
be rerouted to INTA/ at power-up using the INTA/ enable
sense resistor (pull-up on MAD[4]). This causes the
LSI53C896 to program the SCSI Function B PCI Interrupt
Pin register (
) to 0x01. This interrupt pin is disabled if
INT_DIR is driven LOW.
ALT_INTA/
F1
O
16 mA
PCI
Alt Interrupt Function A. When asserted LOW, it indicates
an interrupting condition has occurred in SCSI Function A.
The output drive of this pin is open drain. If the SCSI
Function B interrupt was rerouted at power-up using the
INTA/ enable sense resistor (pull-up on MAD[4]), this signal
indicates that an interrupting condition has occurred in
either the SCSI Function A or SCSI Function B.
ALT_INTB/
G3
O
16 mA
PCI
Alt Interrupt Function B. When asserted LOW, indicates
an interrupting condition has occurred in SCSI Function B.
The output drive of this pin is open drain. This interrupt can
be rerouted to INTA/ at power-up using the INTA/ enable
sense resistor (pull-up on MAD[4]). This causes the
LSI53C896 to program the Function B PCI Interrupt Pin
register (
) to 0x01.
INT_DIR
G2
I
N/A
Interrupt Direction. This input signal indicates whether
internally generated interrupts are presented on INTA/ and
INTB/. If INT_DIR is HIGH, internal interrupts are generated
on both the INTx/ pins and the ALT_INTx pin. If INT_DIR is
LOW, the internal interrupts are generated only on the
ALT_INTx/ pin. This pin has a static pull-up.
1. Refer to Register 0x4D,
in
for details on these signals.