C141-E039-01EN
1 - 7
1.2
Status Byte
Fig. 1.3 shows status byte format and the type of status the IDD supports.
The status byte is one byte of information sent from the TARG to the INIT in the STATUS
phase when one command is completed, and notifies the INIT of the results of the command’s
execution. The status byte is also sent even in cases when the TARG is in a state which it
makes it impossible for it to execute the command when it receives a request for an
input/output operation. However, if the command is cleared by switching to the BUS FREE
phase forcibly through an ABORT message, an ABORT TAG message, a CLEAR QUEUE
message, a BUS DEVICE RESET message, a RESET condition or a SCSI bus error state, etc.,
the status byte for that command is not reported.
After the TARG reports the status byte in the STATUS phase, it will always send a
COMMAND COMPLETE message or a LINKED COMMAND COMPLETE (WITH FLAG)
message, and notify the INIT of the validity of the status byte.
Bit 7
6
5
4
3
2
1
0
0
0
Status Byte Code
0
Bit
5 4 3 2 1
0 0 0 0 0
GOOD Status
0 0 0 0 1
CHECK CONDITION Status
0 0 0 1 0
CONDITION MET Status
0 0 1 0 0
BUSY Status
0 1 0 0 0
INTERMEDIATE Status
0 1 0 1 0
INTERMEDIATE CONDITION MET Status
0 1 1 0 0
RESERVATION CONFLICT Status
1 0 0 0 1
COMMAND TERMINATED Status
1 0 1 0 0
QUEUE FULL Status
Figure 1.3
Status Byte
