Specifications

Upon command completion, the Command Block registers contain the
cylinder, head, and sector number of the last sector written.
If an error occurs during a write of more than one sector, writing
terminates at the sector where the error occurs. The Command Block
registers contain the cylinder, head, and sector number of the sector
where the error occurred. If the no-retry command code (31
H
) is issued,
some or all of the error recovery procedures normally used with this
command may be skipped.
5.4.22 Write Verify
This command (command code 3C
H
) is similar to the Write Sectors
command, except that each sector is verified immediately after being
written. The verify operation is a read without transfer and a check for
data errors. Any errors encountered during the verify operation are
posted. Multiple sector Write Verify commands write all the requested
sectors and then verify all the requested sectors before generating the
final interrupt.
5.5 ATA standard power management commands
The ATA standard command set includes five commands that allow
power management for low-power systems. Power management has
been used primarily in 2.5-inch and smaller drives. However, selected
Seagate 3.5-inch drives support some or all of the power management
commands listed here. These commands switch the drive between four
primary modes of operation, Active mode, Idle mode, Standby mode, and
Sleep mode, as shown in Figure 9.
Active mode. The drive is in Active mode during the read/write and seek
operations.
Idle mode. At power-on, the drive sets the idle timer to enter Idle mode
after five seconds of inactivity. In some cases, the idle timer delay can
be set using the system setup utility. In Idle mode, the spindle remains
up to speed. The heads are parked over the landing zone, away from the
data, for maximum data safety. The buffer remains enabled, and the drive
accepts all commands and returns to Active mode any time disc access
is necessary.
Standby mode. The drive enters Standby mode when a Standby Imme-
diate command has been received from the host. The drive can also enter
Standby mode after a specifiable length of time has elapsed with the
drive in Idle mode. The standby timer delay is system dependent, and is
usually established by the user with a system utility such as Setup. In
ATA Interface Reference Manual, Rev. C 55