150
Western Digital Hard Disk Drive OEM Specification
11.12
Idle (E3h/97h)
Com m and Block Output Registers
Com m and Block Input Registers
Register
7
6
5
4
3
2
1
0
Register
7
6
5
4
3
2
1
0
Data
-
-
-
-
-
-
-
-
Data
-
-
-
-
-
-
-
-
Feature
-
-
-
-
-
-
-
-
Error
...See Below ...
Sector Count
V
V
V
V
V
V
V
V
Sector Count
-
-
-
-
-
-
-
-
Sector
Number
-
-
-
-
-
-
-
-
Sector Number
-
-
-
-
-
-
-
-
Cylinder Low
-
-
-
-
-
-
-
-
Cylinder Low
-
-
-
-
-
-
-
-
Cylinder High
-
-
-
-
-
-
-
-
Cylinder High
-
-
-
-
-
-
-
-
Device/Head
1
-
1
D
-
-
-
-
Device/Head
-
-
-
-
-
-
-
-
Command
1
1
1
0
0
0
1
1
Status
...See Below ...
Error Register
Status Register
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
CRC
UNC
0
IDN
0
ABT
T0N
AMN
BSY
RDY
DF
DSC
DRQ
COR
IDX
ERR
0
0
0
0
0
V
0
0
0
V
0
V
-
0
-
V
Table 123 Idle Command (E3h/97h)
The Idle command causes the device to enter Idle mode immediately, and set auto power down timeout parameter
(standby timer). And then the timer starts counting down.
When the Idle mode is entered, the device is spun up to operating speed. If the device is already spinning, the s pin
up sequence is not executed.
During Idle mode the device is spinning and ready to respond to host commands immediately.
Output Parameters To The Device
Sector Count
Timeout Parameter. If zero, then the automatic power down sequence is disabled. If non-zero,
then the automatic power down sequence is enabled, and the timeout interval is shown below:
Value
Description
----------
-------------------------
0
Timer disabled
1-240
Value * 5
241-251
(Value-240) * 30 minutes
252
21 minutes
253
8 hours
254
Aborted
255
21 minutes 15 seconds
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.