Power Management Features; Power Mode; Power Management Commands; Standby/Sleep Command Completion Timing - IBM IC25N040ATCS04 - Travelstar 40 GB Hard Drive Specifications

11.6 Power management features

The power management feature set permits a host to modify the behavior in a manner which reduces the
power required to operate. The power management feature set provides a set of commands and a timer
that enables a device to implement low power consumption modes.
The drive implements the following set of functions:
1. A Standby timer
2. Idle command
3. Idle Immediate command
4. Sleep command
5. Standby command
6. Standby Immediate command

11.6.1 Power Mode

Sleep Mode The lowest power consumption when the device is powered on occurs in Sleep Mode.
When in sleep mode, the device requires a reset to be activated.
Standby Mode The device interface is capable of accepting commands, but since the media may not
be immediately accessible, there is a delay while waiting for the spindle to reach
operating speed.
Idle Mode Refer to 11.7, "Adaptive Battery Life Extender (ABLE-3) feature" on page 82.
Active Mode The device is in execution of a command or accessing the disk media with the read
look-ahead function or the write cache function.

11.6.2 Power management commands

The Check Power Mode command allows a host to determine if a device is currently in, going to, or leav-
ing standby mode.
The Idle and Idle Immediate commands move a device to idle mode immediately from the active or stand-
by modes. The idle command also sets the standby timer count and starts the standby timer.
The sleep command moves a device to sleep mode. The device's interface becomes inactive at the
completion of the sleep command. A reset is required to move a device out of sleep mode. When a device
exits sleep mode it will enter standby mode.
The Standby and Standby Immediate commands move a device to standby mode immediately from the
active or idle modes. The standby command also sets the standby timer count.

11.6.3 Standby/Sleep command completion timing

1. Confirm the completion of writing cached data in the buffer to media.
2. Unload the heads on the ramp.
3. Set the DRDY bit and the DSC bit in Status Register.
4. Set the INTRQ (completion of the command).
5. Activate the spindle break to stop the spindle motor.
6. Wait until the spindle motor is stopped.
7. Perform the post process.
Travelstar 60GH & 40GN hard disk drive specifications
80