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Western Digital Hard Disk Drive OEM Specification
9.18.3.3 Feature Control Command (action code : 0004h)
Inputs: (Key Sector)
Set or return the state of drive features described in Table 67
Return the current state of a feature
Return feature option flags
See Table 67 for a list of the feature codes
Feature code dependent value
Bit15:1 = Reserved
If the function code is 0001h, setting bit 0 to one causes the
requested feature state change to be preserved across power
cycles.
If the function code is 0001h, setting bit 0 to zero causes the
requested feature state change to be volatile. A hard reset
causes the drive to revert to default, or last non-volatile
setting.
Table 65 Feature Control Command (Inputs)
Outputs: (TF Data)
Command Block Input Registers (Success)
If Function Code was 0002h, then this is the LSB of Feature State.
If Function Code was 0003h, then this is the LSB of Option Flags.
Otherwise, this field is reserved.
If Function Code was 0002h, then this is the MSB of Feature State.
If Function Code was 0003h, then this is the MSB of Option Flags.
Otherwise, this field is reserved.
Table 66 Feature Control Command (Outputs)