Parallel SCSI Interface Product Manual, Rev. A 133
7.2.1 Fixed and variable length Command Descriptor Block formats
For all commands, if there is an invalid parameter in the command descriptor block, the device server termi-
nates the command without altering the medium.
Table 57 shows the typical format of a 6-byte CDB. Table 58 shows a typical format of a 10-byte CDB. Table 59
shows the typical format of a 12-byte CDB. Table 60 shows the typical format of a 16-byte CDB. Table 61
shows the typical format for a variable length CDB.
Table 57: Typical CDB for 6-byte commands
See notes following Table 61.
Table 58: Typical CDB for 10-byte commands
See notes following Table 61.
Bit
Byte
7 6 5 4 3 2 1 0
0
OPERATION CODE [1]
1
Reserved (MSB)
2
LOGICAL BLOCK ADDRESS (if required) [3]
3
(LSB)
4
TRANSFER LENGTH (if required) [4]
PARAMETER LIST LENGTH (if required) [5]
ALLOCATION LENGTH (if required) [6]
5
CONTROL [7]
Bit
Byte
7 6 5 4 3 2 1 0
0
OPERATION CODE [1]
1
Reserved SERVICE ACTION (if required) [2]
2
(MSB)
LOGICAL BLOCK ADDRESS (if required) [3]
3
4
5
(LSB)
6
Reserved
7
(MSB) TRANSFER LENGTH (if required) [4]
PARAMETER LIST LENGTH (if required) [5]
ALLOCATION LENGTH (if required [6]
8
(LSB)
9
CONTROL [7]
