XL500S
ATA Command Set
2679-701211-A06
RELEASED 10/21/10 (WD CONFIDENTIAL)
39
4.4
Set Features (EFh)
The Set Features command enables or disables the features listed in the following table
FUNCTION
FEATURES
REGISTER
SECTOR COUNT REGISTER
Enable read look-ahead
1
AAh
Don’t care
Disable read look-ahead
1
55h
Don’t care
Enable write cache
1
02h
Don’t care
Disable write cache
1
82h
Don’t care
Set Transfer Mode
03h
Don’t care
Enable use of Serial ATA Feature
10h
02h-DMA Setup FIS Auto-Activate optimization
03h-Device-initiated interface power state transitions
06h-Software Settings Preservation
Disable use of Serial ATA Feature
90h
02h-DMA Setup FIS Auto-Activate optimization
03h-Device-initiated interface power state transitions
06h-Software Settings Preservation
Set Acoustic Mode
2
42h
80h
Set Performance Mode
2
42h
FEh
Disable Automatic Acoustic Management
2
C2h
Don’t care
Enable the PUIS feature set
1
06h
Don’t care
Disablethe PUIS feature set
1
86h
Don’t care
PUIS feature set device spinup
1
07h
Don’t care
Enable/disable reverting to defaults
1
66h
Don’t care
1
Changes are only valid while power remains applied to the drive. After power is cycled, the drive reverts to the default
settings.
2
Changes are valid through power cycles and hard resets.