Seagate ST9160823AS ユーザーズマニュアル

30

Momentus 7200.2 SATA Product Manual, Rev. E

This command controls the implementation of various features that the drive supports. When the drive receives 
this command, it sets BSY, checks the contents of the Features register, clears BSY and generates an inter-
rupt. If the value in the register does not represent a feature that the drive supports, the command is aborted. 
Power-on default has the read look-ahead and write caching features enabled. The acceptable values for the 
Features register are defined as follows:

4

Ultra DMA mode 4 is supported.

8

Ultra DMA mode 0 is currently active.

9

Ultra DMA mode 1 is currently active.

10

Ultra DMA mode 2 is currently active.

11

Ultra DMA mode 3 is currently active.

12

Ultra DMA mode 4 is currently active.

13

Ultra DMA mode 5 is currently active.

13

1 = 80-conductor cable detected, CBLID above V

IH

 

 

0 = 40-conductor cable detected, CBLID below V

IL

02

H

Enable write cache (default).

03

H

Set transfer mode (based on value in Sector Count register).
Sector Count register values:

00

H

Set PIO mode to default (PIO mode 2).

01

H

Set PIO mode to default and disable IORDY (PIO mode 2).

08

H

PIO mode 0

09

H

PIO mode 1

0A

H

PIO mode 2 

0B

H

PIO mode 3

0C

H

PIO mode 4 (default)

20

H

Multiword DMA mode 0

21

H

Multiword DMA mode 1

22

H

Multiword DMA mode 2

40

H

Ultra DMA mode 0

41

H

Ultra DMA mode 1

42

H

Ultra DMA mode 2

43

H

Ultra DMA mode 3

44

H

Ultra DMA mode 4

45

H

Ultra DMA mode 5

41

H

Enable the Free Fall Protection feature (default on ST9160823ASG and ST980813ASG models)

 

(C1

H

 below disables the Free Fall Protection feature)

55

H

Disable read look-ahead (read cache) feature.

82

H

Disable write cache

AA

H

Enable read look-ahead (read cache) feature (default).