Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
157
supported by the Target, respectively corresponding to an absent Block Descriptor, a single Short LBA Block
Descriptor, and a single Long LBA Block Descriptor.
Note: DPOFUA is ignored during Mode Select command processing although the SCSI Standard states that it is
reserved during Mode Select. Ignoring it allows the Mode Sense Parameter List for the byte containing this bit
to be re-used as a Mode Select Parameter List.
18.10.1.2
Block Descriptors
Table 131 Short LBA Mode Parameter Block Descriptor
Byte
Bit
7
6
5
4
3
2
1
0
0 - 3
(MSB)
Number of Blocks
(LSB)
4
Reserved = 0
5 - 7
(MSB)
Block Length
(LSB)
Table 132 Long LBA Mode Parameter Block Descriptor
Byte
Bit
7
6
5
4
3
2
1
0
0 - 7
(MSB)
Number of Blocks
(LSB)
8-11
Reserved = 0
12-15
(MSB)
Block Length
(LSB)
The Block descriptor provides formatting information about the Number of Blocks (user addressable) to format at the
specified Block Length.
- Number of Blocks, when used with the MODE SELECT command, indicates the number of blocks to
format
- Zero to indicate not to change available blocks
- 0xFFFFFFFF (Short LBA) or 0xFFFFFFFFFFFFFFFF (Long LBA) to indicate all available blocks
- The exact number of blocks in the data area of the drive, which can be obtained with the MODE SENSE
- The number of blocks less than exact one, in order to CLIP the number of blocks
Any other value is invalid and causes the command to fail with Check Condition status.
When returned by the MODE SENSE command, the field contains the exact number of blocks.
- Block Length field reflects the number of bytes of user data per sector (not including any protection
information). When used with the MODE SELECT command, the Block Length field must contain a value
from 512, 520, 528 or zero for all models and 4096, 4112, 4160, 4224 for models which support format with
4k nominal block sizes. Otherwise the drive will terminate the command with Check Condition status.
A FORMAT UNIT command is required to cause these parameters to become current only if the block length
parameter is different from the current block length.