Hitachi HUS154530VLF400 User Manual

                                    

Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification

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The Block descriptor provides formatting information about the Number of Blocks (user addressable) to format at the speci-
fied Block Length.

• Number of Blocks

When used with the MODE SELECT command, the Number of Blocks field must be

-      Zero to indicate not to change available blocks

-      0xFFFFFFFF 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 used with the MODE SENSE command, the field contains the exact number of blocks.

• Density Code

-     Always 0 for direct access devices.

• Block Length

The Block Length field reflects the number of bytes of user data per sector (not including any protection informa-
tion). When used with the MODE SELECT command, the Block length field must contain the value from 512 to 528 
(8 bytes step) or zero. 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 param-
eter is different from the current block length.

When used with the MODE SENSE command, the field is dependent on how the media is currently formatted.