1 all_commands parameter data format – Hitachi ULTRASTAR 15K450 HUS154530VLF400 User Manual
Page 269
Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
253
19.32.1 All_commands parameter data format
The Report Supported Operation Codes all_command parameter data format begins with a four-byte header that contains the
length in bytes of the parameter data, followed by a list of supported commands. Each command descriptor contains informa-
tion about a single supported command CDB (i.e. one operation code and service action combination, or one non-service-
action operation code).
Each Command Descriptor contains information about a single supported command CDB.
Operation Code contains the operation code of a supported command.
Service Action contains a supported serivce action of the supported operation. If the operation code does not have a service
action, the Service Action field will be set to zero.
SERVACTV set to zero indicates the operation code does not have service actions and the Service Action field should be
ignored. SERVACTV set to one indicates the operation code field has service actions and the contents of the Service Action
field are valid.
CDB Length contains the length of the command CDB in bytes.
Byte
Bit
7
6
5
4
3
2
1
0
0-3
Command Data Length (n-3)
4
Command Descriptor 0
N
Command Descriptor X
Byte
Bit
7
6
5
4
3
2
1
0
0
Operation Code
1
Reserved = 0
2-3
Service Action
4
Reserved = 0
5
Reserved = 0
SERVACTV
6-7
CDB Length