Write Cache Function; Reassign Function; Table 39: Seek Overlap - Hitachi HTS541010G9AT00 - Travelstar 100 GB Hard Drive Specifications

Table 39: Seek overlap

(1) With overlap
Host process
Device process
Seek operation
Overhead
Total time = (n-1) * (Seek operation) + A + B
(2) Without overlap
Host process
Device process
Seek operation
Overhead
Total time = n * (Seek operation + A + B)

10.12 Write Cache function

Write cache is a performance enhancement whereby the device reports completion of the write command (Write
Sector(s) and Write Multiple) to the host as soon as the device has received all of the data in its buffer. The device
assumes responsibility to write the data subsequently onto the disk.
• Writing data after completed acknowledgment of a write command, soft reset, or COMRESET
does not affect its operation but power off terminates writing operation immediately and
unwritten data is lost.
• Flush cache, Soft reset, Standby, Standby Immediate, and Sleep are executed after the comple-
tion of writing to disk media on enabling write cache function. The host system can confirm
the completion of Write Cache operation by issuing Flush Cache command, Soft reset, Standby
command, Standby Immediate command, or Sleep command, and then confirming the comple-
tion of the issued command.

10.13 Reassign Function

The Reassign Function is used with read commands and write commands. The sectors of data for reassignment are
prepared as the spare data sector. The one entry can register 256 consecutive sectors maximum.
This reassignment information is registered internally, and the information is available right after completing the
reassign function. Also the information is used on the next power on reset or hard reset.
If the number of the spare sector reaches 0 sector, the reassign function will be disabled automatically.
The spare tracks for reassignment are located at regular intervals from Cylinder 0. As a result of reassignment, the
physical location of logically sequenced sectors is dispersed.
A
A
Travelstar 5K100 (Serial ATA) Hard Disk Drive Specification
B+A
67
B
B+A
B