Scsi interrupt status one (sist1), Scsi, Interrupt status one (sist1) – LSI 53C810A User Manual

Page 127: Scsi interrupt, Status one (sist1), Scsi interrupt status one, Sist1)

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5-53

when the LSI53C810A operates in the initiator mode.
When the LSI53C810A operates in low level mode, any
disconnect causes an interrupt, even a valid SCSI
disconnect. This bit is also set if a selection time-out
occurs (it may occur before, at the same time, or stacked
after the STO interrupt, since this is not considered an
expected disconnect).

RST

SCSI RST/ Received

1

This bit is set when the LSI53C810A detects an active
SRST/ signal, whether the reset was generated external
to the chip or caused by the Assert SRST/ bit in the

SCSI

Control One (SCNTL1)

register. This SCSI reset

detection logic is edge-sensitive, so that multiple
interrupts are not generated for a single assertion of the
SRST/ signal.

PAR

Parity Error

0

This bit is set when the LSI53C810A detects a parity
error while receiving SCSI data. The Enable Parity
Checking bit (bit 3 in the

SCSI Control Zero (SCNTL0)

register) must be set for this bit to become active. The
LSI53C810A always generates parity when sending SCSI
data.

Register: 0x43 (0xC3)

SCSI Interrupt Status One (SIST1)
Read Only

Reading the

SCSI Interrupt Status One (SIST1)

register returns the

status of the various interrupt conditions, whether they are enabled in the

SCSI Interrupt Enable One (SIEN1)

register or not. Each bit that is set

indicates an occurrence of the corresponding condition.

Reading the

SCSI Interrupt Status One (SIST1)

register clears the

interrupt condition.

7

3

2

1

0

R

STO

GEN

HTH

x

x

x

x

x

0

0

0

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