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11.52 Standby (E2h/96h)
Com m and Block Output Registers
Register
7
6
Data
-
-
Feature
-
-
Sector Count
V
V
Sector Number
-
-
Cylinder Low
-
-
Cylinder High
-
-
Device/Head
1
-
Command
1
1
Error Register
7
6
5
4
CRC
UNC
0
IDN
0
0
0
0
Table 243 Standby Command (E2h/96h)
The Standby command causes the device to enter the Standby Mode immediately, and set auto power down timeout
parameter (standby timer).
When the Standby mode is entered, the drive is spun down but the interface remains active. If the drive is already
spun down, the spin down sequence is not executed.
During the Standby mode the device will respond to commands, but there is a delay while waiting for the spindle to
reach operating speed.
The automatic power down sequence is enabled and the timer starts counting down when the drive returns to Idle
mode.
If the EPC feature set is enabled, device enters into the Standby_Z power condition.
Output Parameters To The Device
Sector Count
Timeout Parameter. If zero, the timeout interval (Standby Timer) is NOT disabled. If non-zero,
then the automatic power down sequence is enabled, and the timeout interval is shown blow:
When the automatic power down sequence is enabled, the drive will enter Standby mode automatically if the timeout
interval expires with no drive access from the host. The timeout interval will be reinitialized if there is a drive access
before the timeout interval expires.
5
4
3
2
1
0
-
-
-
-
-
-
-
-
-
-
-
-
V
V
V
V
V
V
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
1
D
-
-
-
-
1
0
0
0
1
0
3
2
1
0
0
ABT
T0N
AMN
0
V
0
0
Western Digital Hard Disk Drive OEM Specification
Com m and Block Input Registers
Register
7
6
Data
-
-
Error
Sector Count
-
-
Sector Number
-
-
Cylinder Low
-
-
Cylinder High
-
-
Device/Head
-
-
Status
Status Register
7
6
5
4
BSY
RDY
DF
DSC
0
V
0
V
Value
Description
------------
-------------------------------
0
Timer disabled
1-240
Value * 5 seconds
241-251
(Value-240) * 30 minutes
252
21 minutes
253
8 hours
254
Aborted
21 minutes 15 seconds
255
278
5
4
3
2
1
-
-
-
-
-
...See Below ...
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
...See Below ...
3
2
1
0
DRQ COR
IDX
ERR
-
0
-
V
0
-
-
-
-
-
-
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