Hitachi HCS721075CLA332 Feature Control Command action code 0004h, Feature Control command Inputs

9.18.3.3Feature Control Command (action code : 0004h)

Inputs: (Key Sector)

Word	Name	Value	Description
0	Action Code	0004h	Set or return the state of drive features described in 0
1	Function Code	0001h	Set state for a feature
		0002h	Return the current state of a feature
		0003h	Return feature option flags
2	Feature Code	Word	See 0 for a list of the feature codes
3	State	Word	Feature code dependent value
4	Option Flags	Word	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.
255:5	reserved	0000h

Table 59 Feature Control command (Inputs)

Outputs: (TF Data)

Command Block Input Registers (Success)

Error	00h
Sector Count	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.
Sector Number	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.
Cylinder Low	reserved
Cylinder High	reserved
Device/Head	reserved
Status	50h

Table 60 Feature Control command (Outputs)

Hitachi hard disk drive specifications

95