Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
218
18.22
READ CAPACITY (10) - (25)
Table 185 READ CAPACITY (10) - (25)
Byte
Bit
7
6
5
4
3
2
1
0
0
Command Code = 25h
1
Reserved = 0
Reserved = 0
Obsolete
2-5
(MSB)
Logical Block Address
(LSB)
6-7
Reserved = 0
8
Reserved = 0
PMI
9
VU = 0
Reserved = 0
FLAG
LINK
The READ CAPACITY command returns information regarding the capacity of the drive.
- Logical Block Address is used in conjunction with the PMI bit.
- PMI (Partial Medium Indicator) indicates:
This option provides the information that the Initiator needs to determine the amount of space available on the same
track that is accessible without a head switch or seek.
PMI
Description
0
The drive returns the last LBA of the drive.
1
The drive returns the last LBA and block length in bytes are that of the LBA after which a substantial
delay in data transfer will be encountered. This returned LBA shall be greater than or equal to the LBA
specified by the LBA fields in the CDB.
18.22.1
Returned Data Format
The data returned to the Initiator in response to the READ CAPACITY command is described here. The data is
returned in the DATA IN phase.
Table 186 Format of READ CAPACITY command reply
Byte
Bit
7
6
5
4
3
2
1
0
0-3
(MSB)
Maximum Logical Block Address
(LSB)
4-7
(MSB)
Block Length
(LSB)
- Block Length specifies the length in bytes of each block of user data (not including protection information).