Avago Technologies LSI53C896 - Manual (Page 189)

SCSI Registers 4-77
Version 3.3 Copyright © 1998–2003 by LSI Logic Corporation. All rights reserved.
SGE SCSI Gross Error 3
The following conditions are considered SCSI Gross Errors:
•
Data underflow – reading the SCSI FIFO when no
data is present.
•
Data overflow – writing to the SCSI FIFO while it is full.
•
Offset underflow – receiving a SACK/ pulse in the
target mode before the corresponding SREQ/ is sent.
•
Offset overflow – receiving a SREQ/ pulse in the initiator
mode, and exceeding the maximum offset (defined by
the MO[3:0] bits in the
SCSI Transfer (SXFER) register).
•
A phase change in the initiator mode, with an
outstanding SREQ/SACK offset.
•
Residual data in SCSI FIFO – starting a transfer other
than synchronous data receive with data left in the
SCSI synchronous receive FIFO.
UDC Unexpected Disconnect 2
This condition only occurs in the initiator mode. It
happens when the target to which the LSI53C896 SCSI
function is connected disconnects from the SCSI bus
unexpectedly. Refer to the SCSI Disconnect Unexpected
bit in the
SCSI Control Two (SCNTL2) register for details
about expected versus unexpected disconnects. Any
disconnect in the low level mode causes this condition.
RST SCSI Reset Condition 1
Indicates assertion of the SRST/ signal by the
LSI53C896 SCSI function or any other SCSI device. This
condition is edge-triggered, so multiple interrupts cannot
occur because of a single SRST/ pulse.
PAR SCSI Parity Error 0
Indicates detection by the LSI53C896 SCSI function of a
parity error while receiving or sending SCSI data. Refer
to the Disable Halt on Parity Error or SATN/ Condition bits
in the
SCSI Control One (SCNTL1) register for details on
when this condition is raised.