Fujitsu MHA2021AT, MHA2032AT manual Host Commands

5.3 Host Commands

At command issuance (I/O registers setting contents)

1F7H(CM)	1	1	1	1	1	0	0	0
1F6H(DH)	×	×	´	DV	xx
1F5H(CH)	xx
1F4H(CL)	xx
1F3H(SN)	xx
1F2H(SC)	xx
1F1H(FR)	xx

At command completion (I/O registers contents to be read)

1F7H(ST)	Status information
1F6H(DH)	×	×	×	DV	xx
1F5H(CH)	xx
1F4H(CL)	xx
1F3H(SN)	xx
1F2H(SC)	xx
1F1H(ER)	Error information

(21) IDLE (X’97’ or X’E3’)

Upon receipt of this command, the device sets the BSY bit of the Status register, and enters the idle mode. Then, the device clears the BSY bit, and generates an interrupt. The device generates an interrupt even if the device has not fully entered the idle mode. If the spindle of the device is already rotating, the spin-up sequence shall not be implemented.

By using this command, the automatic power-down function is enabled and the timer immediately starts the countdown. When the timer reaches the specified value, the device enters standby mode.

Enabling the automatic power-down function means that the device automatically enters the standby mode after a certain period of time. When the device enters the idle mode, the timer starts countdown. If any command is not issued while the timer is counting down, the device automatically enters the standby mode. If any command is issued while the timer is counting down, the timer is initialized and the command is executed. The timer restarts countdown after completion of the command execution.

The period of timer count is set depending on the value of the Sector Count register as shown below.

C141-E042-01EN 5-47