Set Features (Efh) - Western Digital Blue WD20SPZX Technical Reference Manual

4.4

Set Features (EFh)

The Set Features command enables or disables the features listed in the following
table
FUNCTION
Enable read look-ahead
Disable read look-ahead
Enable write cache
Disable write cache
Set Transfer Mode
Enable use of Serial ATA Feature
Disable use of Serial ATA Feature
Enable the PUIS feature set
Disable the PUIS feature set
PUIS feature set device spinup
Enable/disable reverting to defaults
1
Changes are only valid while power remains applied to the drive. After power is cycled, the drive
reverts to the default settings.
ATA Command Set
FEATURES
REGISTER
1
AAh
1
55h
1
02h
1
82h
03h
10h
90h
1
06h
1
86h
1
07h
1
66h
WESTERN DIGITAL CONFIDENTIAL
- 55 -
SECTOR COUNT REGISTER
Don't care
Don't care
Don't care
Don't care
Don't care
02h-DMA Setup FIS Auto-Activate optimization
03h-Device-initiated interface power state
transitions
06h-Software Settings Preservation
02h-DMA Setup FIS Auto-Activate optimization
03h-Device-initiated interface power state
transitions
06h-Software Settings Preservation
Don't care
Don't care
Don't care
Don't care