4.5 ATA Commands
C156-E205-01EN 4-35
4.5.10 SET FEATURES (EFh)
Table 4.31 SET FEATURES command
Bit
76543210
CM11101111
DHXXXDEVXXXX
CHXXXXXXXX
CLXXXXXXXX
SNXXXXXXXX
SC Setting value
FR Setting value
The SET FEATURES command changes the ODD operating mode to the mode
set in the SC and FR registers. If the specified value is not supported by the ODD
or an invalid value, the ODD reports Aborted Command.
Table 4.32 FR register setting value
Setting
value
Function Default
value
02 Enables the write cache. *
03 Supports data transfer depending on the value of the SC register. See Table
4.33.
31
31 Disables the media status notification function. *
55 Disables the read ahead cache.
66 Does not reset various setting values to the power-on default value by
software reset. (The media status notification function is reset normally.)
*
82 Disables the write cache.
95 Enables the media status notification function.
AA Enables the read ahead cache. *
CC Returns various setting values to the power-on default value by software
reset.