Scsi interrupt status one (sist1), Register: 0x43 – Avago Technologies LSI53C1010R User Manual
Page 195
SCSI Registers
4-77
Version 2.2
Copyright © 2000–2003 by LSI Logic Corporation. All rights reserved.
Register: 0x43
SCSI Interrupt Status One (SIST1)
Read Only
Reading the 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 set indicates
an occurrence of the corresponding condition. Reading SIST1 clears the
interrupt condition.
R
Reserved
[7:5]
SBMC
SCSI Bus Mode Change
4
This bit is set when the DIFFSENS pin detects a change
in voltage level indicating the SCSI bus has switched
between SE, LVD, or HVD modes.
R
Reserved
3
STO
Selection or Reselection Time-Out
2
This bit is set when the SCSI device which the
LSI53C1010R SCSI function is attempting to select or
reselect does not respond within the programmed
time-out period. Refer to the description of the
register, bits [3:0], for details
on the time-out timer.
GEN
General Purpose Timer Expired
1
This bit is set when the general purpose timer expires.
The time measured is the time between enabling and
disabling of the timer. Refer to the description of the
register, bits [3:0], for details
on the general purpose timer.
HTH
Handshake-to-Handshake Timer Expired
0
This bit is set when the handshake-to-handshake timer
expires. The time measured is the SCSI
Request-to-Request (target) or
7
5
4
3
2
1
0
R
SBMC
R
STO
GEN
HTH
0
0
0
0
0
0
0
0