Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
240
18.33.1
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 information about a single supported command CDB (i.e. one operation code and service action
combination, or one non-service action operation code).
Table 218 All_command parameter data format
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
Each Command Descriptor contains information about a single supported command CDB.
Table 219 Command Descriptor format
Byte
Bit
7
6
5
4
3
2
1
0
0-3
Operation Code
1
Reserved = 0
2-3
Service Action
4
Reserved = 0
5
Reserved = 0 CTDP
Serva
ctv
6-7
CDB Length
8-19
Command Timeouts Descriptor, if any
(see 18.34.3 "Command timeouts descriptor format")
Operation Code contains the operation code of a supported command.
Service Action contains a supported service action of the supported operation. If the operation code does not have
a service action, the Service Action field will be set to zero.
CTDP: A command timeouts descriptor present bit set to one indicates that the command timeouts descriptor (see
18.32.3) is included in this command descriptor. A CTDP bit set to zero indicates that the command timeouts
descriptor is not included in this command descriptor.
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.