Scsi Bus Status; 3-3.1 Good Status; 3-3.2 Check Condition; 3-3.3 Busy Status - Fujitsu M2488 Product Manual

SCSI MESSAGES
3-3

SCSI BUS STATUS

A status byte, Table 3-3, is sent from the target to the initiator during the STATUS phase at the termina-
tion of each command unless the command is cleared by:
An ABORT message,
A BUS DEVICE RESET message,
A "hard" RESET condition, or
An unexpected BUS FREE condition.
BYTES 7
0
Reserved
Table 3-4 describes the status byte codes:
STATUS BYTE BITS
7 6 5
R R 0
R R 0
R R 0
R R 0
R R 0
R R 0
R R 0
R R 1
R R 1
All Other Codes
R- Reserved bit
*- Not supported by this controller
3-3.1 Good Status
This status indicates the target has successfully completed the command.
3-3.2 Check Condition
Any error, exception, or abnormal condition that causes sense data to be set, causes a CHECK CON-
DITION status. The REQUEST SENSE command is issued following a CHECK CONDITION sta-
tus, to determine the nature of the condition.
3-3.3 Busy Status
The target is busy. This status is returned whenever a target is unable to accept a command from an
otherwise acceptable initiator. The normal initiator recovery action is to issue the command again at a
later time.
3-3.4 Intermediate Status
This status is returned for every command in a series of linked commands (except the last command),
unless an error, exception, or abnormal condition causes a CHECK CONDITION status or a RESER-
3-10

Table 3-3. Status Byte

BITS
6 5 4
Status Byte Code

Table 3-4. Status Byte Code Bit Values

4 3 2 1 0
0 0 0 0 R
0 0 0 1 R
0 0 1 0 R
0 1 0 0 R
1 0 0 0 R
1 0 1 0 R
1 1 0 0 R
0 0 0 1 R
0 1 0 0 R
CG00000-011503 REV. A
M2488 PRODUCT GUIDE
3 2 1
STATUS REPRESENTED
Good
Check condition
Condition met/good *
Busy
Intermediate/good
Intermediate condition met/good *
Reservation conflict
Command terminated *
Queue full *
Reserved
0
Reserved
April 1997