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11.46 Set Features (EFh)
Com m and Block Output Registers
Register
7
6
Data
-
-
Feature
V
V
Sector Count
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 212 Set Features Command (EFh)
The Set Feature command is to establish the following parameters which affect the execution of certain features as
shown in below table.
ABT will be set to 1 in the Error Register if the Feature register contains any undefined values.
Output Parameters To The Device
Feature
Destination code for this command
02H
Enable write cache
03H
Set transfer mode based on value in sector count register
05H
Enable Advanced Power Management
06H
Enable Power-up in Standby feature set
07H
Power-Up In Standby feature set device spin-up
10H
Enable use of Serial ATA feature
43H
Set Maximum Host Interface Sector Time
4Ah
Extended Power Conditions
55H
Disable read look-ahead feature
66H
Disable reverting to power on defaults
82H
Disable write cache
85H
Disable Advanced Power Management
86H
Disable Power-up in Standby mode
90H
Disable use of Serial ATA feature
AAH
Enable read look-ahead feature
CCH
Enable reverting to power on defaults
Note.
After power on reset or hard reset, the device is set to the following features as default.
Write cache
Read look-ahead
Reverting to power on defaults
Release interrupt
5
4
3
2
1
0
-
-
-
-
-
-
V
V
V
V
V
V
Note.1
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
1
D
-
-
-
-
1
0
1
1
1
1
3
2
1
0
0
ABT
T0N AMN
0
V
0
0
: Enable
: Enable
: Disable
: Disable
Western Digital Hard Disk Drive OEM Specification
Com m and Block Input Registers
Register
7
6
Data
-
-
...See Below ...
Error
Sector Count
-
-
Sector Number
-
-
Cylinder Low
-
-
Cylinder High
-
-
Device/Head
-
-
...See Below ...
Status
Status Register
7
6
5
4
BSY
RDY
DF
DSC DRQ COR
0
V
0
-
242
5
4
3
2
1
0
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
3
2
1
0
IDX
ERR
-
0
-
V
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