Specifications

Note. Power management commands for all other Seagate ATA-inter-

face drives that support power management are described in

Section 5.6.

Power-save mode and the power-save timer are used in regard to the

alternative Seagate power commands. These are functionally equivalent

to Idle Mode and the idle timer, respectively.

5.7.1 Check Idle Mode command

This command (command code FD

) reports whether the drive is cur-

rently in or making a transition to Idle mode. When the drive receives this

command, it sets BSY, loads the appropriate information into the Sector

Count register, clears BSY and generates an interrupt. Depending on

what state the drive is in or making a transition to, one of the following

values is sent:

= The drive is in, or entering, Idle mode.

= The drive is in, or entering, Active mode or Standby mode.

5.7.2 Check Standby Power Mode command

This command (command code E5

) returns a code for the power mode

the drive is currently in or making a transition to. When the drive receives

this command, it sets BSY, returns a value through the Sector Count

interrupt. The return values are as follows:

= The drive is in, or entering, Standby mode.

= The drive is in, or entering, Active mode or Power-Save mode.

5.7.3 Enable/Disable Auto Idle command

This command (command code FA

) enables and disables the Automat-

ic Idle feature of the drive. When the drive receives this command, it sets

BSY, switches to Idle mode and enables or disables the power-save timer

according to the value placed in the Sector Count register. The drive then

clears BSY and generates an interrupt.

If the value in the sector count is zero, the idle timer is disabled. If the

value is nonzero, the drive switches to Idle mode after the specified delay

time has elapsed. The delay time is specified in the Sector Count register

in 100-msec increments. The delay is reset to its initial value whenever

any command requiring a read, write or seek is received.

62 ATA Interface Reference Manual, Rev. C