Fujitsu M2488 manual Scsi BUS Status

SCSI MESSAGES M2488 PRODUCT GUIDE

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.

Table 3-3. Status Byte

						BITS
BYTES	7		6	5	4		3	2	1	0
0		Reserved				Status Byte Code				Reserved

Table 3-4 describes the status byte codes:

Table 3-4. Status Byte Code Bit Values

		STATUS BYTE BITS						STATUS REPRESENTED
7	6	5	4	3	2	1	0
R	R	0	0	0	0	0	R	Good
R	R	0	0	0	0	1	R	Check condition
R	R	0	0	0	1	0	R	Condition met/good *
R	R	0	0	1	0	0	R	Busy
R	R	0	1	0	0	0	R	Intermediate/good
R	R	0	1	0	1	0	R	Intermediate condition met/good *
R	R	0	1	1	0	0	R	Reservation conflict
R	R	1	0	0	0	1	R	Command terminated *
R	R	1	0	1	0	0	R	Queue full *
All Other Codes								Reserved
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 CG00000-011503 REV. A April 1997