Features Register; Sector Count Register; Sector Number Register - Hitachi HDS723020BLA642 Specifications

8.9

Features Register

This register is command specific. This is used with the Set Features command, SMART Function Set command
and Format Unit command.

8.10 Sector Count Register

This register contains the number of sectors of data requested to be transferred on a read or write operation
between the host and the device. If the value in the register is set to 0, a count of 256 sectors (in 28-bit
addressing) or 65,536 sectors (in 48-bit addressing) is specified.
If the register is zero at command completion, the command was successful. If not successfully completed, the
register contains the number of sectors which need to be transferred in order to complete the request.
The contents of the register are defined otherwise on some commands. These definitions are given in the
command descriptions.

8.11 Sector Number Register

This register contains the starting sector number for any disk data access for the subsequent command.
The sector number is from one to the maximum number of sectors per track.
In LBA mode, this register contains Bits 0-7. At the end of the command, this register is updated to reflect the
current LBA Bits 0-7.
When 48-bit commands are used, the "most recently written" content contains LBA Bits 0-7, and the "previous
content" contains Bits 24-31.
Hitachi hard disk drive specifications
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