Standby/Sleep Command Completion Timing; Standby Timer; Status; Interface Capability For Power Modes - IBM IC25N020ATDA04 - Travelstar 20 GB Hard Drive Specifications

The Idle and Idle Immediate commands move a device to idle mode immediately from the active or
standby 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 com-
pletion 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.

11.5.3 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.

11.5.4 Standby timer

The standby timer provides a method for the device to automatically enter standby mode from either
active or idle mode following a host programmed period of inactivity. If the device is in the active or idle
mode, the device waits for the specified time period and if no command is received, the device automa-
tically enters the standby mode.
If the value of the SECTOR COUNT register on Idle command or the Standby command is set to "00h",
the device will automatically set the standby timer to 109 minutes.

11.5.5 Status

In the active, idle, and standby modes, the device shall have the RDY bit of the status register set. If the
BSY bit is not set, the device shall be ready to accept any command.
In sleep mode, the device interface is not active. A host shall not attempt to read the device's status or
issue commands to the device.

11.5.6 Interface Capability for Power Modes

Each power mode affects the physical interface as defined in the following table:
Mode
Active
Idle
Standby
Sleep

Figure 64. Power conditions

Ready (RDY) is not a power condition. A device may post ready at the interface even though the media
may not be accessible.
BSY RDY
x x
o 1
o 1
x x
Travelstar 48GH, 30GN & 15GN hard disk drive specifications
Interface
active
Yes
Yes
Yes Inactive
No Inactive
84
Media
Active
Active