Specifications

INTERFACE COMMANDS
7 – 54
When enabling the Automatic Power Down sequence, the value placed in the Sector Count register is multiplied
by five seconds to obtain the Time-out Interval value. If no drive commands are received from the host within the
Time-out Interval, the drive automatically enters the STANDBY mode. The minimum value is 5 seconds.
TIMER VALUE TIME-OUT PERIOD
0 Time-out disabled
1 - 240 (value * 5) seconds
241 - 251 ((value - 240) * 30) minutes
252 21 minutes
253 Vendor unique period = 10 hours
254 Reserved
255 21 minutes, 15 seconds
While the drive is in STANDBY MODE, any commands received from the host are accepted and executed as
they would in normal operation, except that the spin motor is started if required to execute a disk command.
Under these conditions, the drive will set BSY when command processing would normally begin and will leave
BSY set until the drive comes up to speed and the disk command can be executed. Disk commands issued while
the drive is in STANDBY MODE, restarts the Time-out Interval after completing the command. A reset must be
issued before attempting to issue any commands while the drive in
SLEEP MODE.