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Avago Technologies LSI53C895A User Manual

Page 183

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SCSI Registers

4-75

Disable Halt on Parity Error or SATN/ Condition bit in the

SCSI Control One (SCNTL1)

register for more

information on when this status is actually raised.

CMP

Function Complete

6

Indicates full arbitration and selection sequence is
completed.

SEL

Selected

5

Indicates the LSI53C895A is selected by a SCSI initiator
device. Set the Enable Response to Selection bit in the

SCSI Chip ID (SCID)

register for this to occur.

RSL

Reselected

4

Indicates the LSI53C895A is reselected by a SCSI target
device. Set the Enable Response to Reselection bit in the

SCSI Chip ID (SCID)

register for this to occur.

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 target
mode before the corresponding SREQ/ is sent.

Offset overflow – receiving an 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 LSI53C895A is
connected disconnects from the SCSI bus unexpectedly.
See the SCSI Disconnect Unexpected bit in the

SCSI