Specifications

5.7.8 Ready Immediate command
When the drive receives this command (command codes E1
H
and F9
H
),
it sets BSY and enters Active mode. If the drive is in Standby mode, the
spinup routine is executed. (If the drive is in either Active mode or Idle
mode, the spindle is already up to speed, and the spinup routine is
skipped.) Then, the drive clears BSY and generates an interrupt. This
interrupt is generated even if the drive is not fully in Active mode.
5.7.9 Sleep command
This command (command code E6
H
) tells the drive to enter Sleep mode
immediately. When the drive receives this command, it sets BSY, enters
Sleep mode, clears BSY and generates an interrupt. After the final
interrupt is generated, all successive interrupts are ignored. When a soft
reset is sent from the host, the drive leaves Sleep mode and makes a
transition to Standby mode. If a hard reset is sent from the host, the drive
returns to Active mode. After a soft reset is received, the drive exits Sleep
mode with all emulation and translation parameters intact.
5.7.10 Standby Immediate command
This command (command code E0
H
) causes the drive to enter Standby
mode. When the drive receives this command, it asserts Busy in the host
Status register, initiates entry into Standby mode, negates Busy, and
generates an interrupt.
If the drive is in Active mode or Idle mode, it spins down to enter Standby
mode. The drive does not wait to complete the spindown before gener-
ating the interrupt.
64 ATA Interface Reference Manual, Rev. C