Power Management - Seagate ST5660A Product Manual

ST5660A Product Manual, Rev. A

1.9.2 Power management

This drive provides and uses power-management modes which reduce
power consumption. The level of drive activity for each power-manage-
ment mode is described below.
You can customize the power-management modes using the AT inter-
face commands that control the power modes. These commands are
described in the Seagate ATA Interface Reference Manual , publication
number 36111- xxx .
Note. If you install the ST5660A as a slave with a master drive that does
not support power management (for example, a Seagate
ST1239A drive), do not send power-management commands to
the ST5660A.
1.9.2.1 Power-management modes 1.9.2.1
The drive supports the following power-management modes:
• Spinup. The drive brings the spindle and discs up to operating speed.
Power in this mode is defined as the average power during the first
10 seconds of spinup. The drive enters this mode during startup and
from the Standby mode.
• Seeking. The drive moves the read/write heads to a specific location
on the disc surface in preparation for reading from or writing to the
disc. Read/write electronics are powered down and servo electronics
are active. The power measured during this mode is the average
power while executing random seeks with a 2-revolution (26.6 msec)
dwell between Seek commands.
• Read/write. The drive reads from or writes to the disc. Read/write
electronics are active and the servo is on track. The drive enters this
mode from the Idle mode.
• Idle. The heads are parked in the shipping zone. The spindle is
spinning and the cache buffer remains enabled, and the drive accepts
all commands and returns to the Seeking or Read/write modes when
it receives a command that requires disc access.
• Standby. The spindle is stopped, the heads are parked in the landing
zone, the actuator is latched, and some of the drive electronics are
powered down. The drive sets a status flag indicating to the computer
that it is ready to access the disc. When the drive receives a command
that does not require disc access, the drive remains in the Standby
mode. When the drive receives a command that requires disc access,
it spins up and performs the command.
7