Set Features Command - Seagate ST400FM0012 Product Manual

4.3.2

Set Features command

This command controls the implementation of various features that the drive supports. When the drive receives
this command, it sets BSY, checks the contents of the Features register, clears BSY and generates an inter-
rupt. If the value in the register does not represent a feature that the drive supports, the command is aborted.
Power-on default has the read look-ahead and write caching features enabled. The acceptable values for the
Features register are defined as follows:
Table 8: Set Features command values
02 Enable write cache (default).
H
03 Set transfer mode (based on value in Sector Count register).
H
Sector Count register values:
00 Set PIO mode to default (PIO mode 2).
H
01 Set PIO mode to default and disable IORDY (PIO mode 2).
H
08 PIO mode 0
H
09 PIO mode 1
H
0A PIO mode 2
H
0B PIO mode 3
H
0C PIO mode 4 (default)
H
20 Multiword DMA mode 0
H
21 Multiword DMA mode 1
H
22 Multiword DMA mode 2
H
40 Ultra DMA mode 0
H
41 Ultra DMA mode 1
H
42 Ultra DMA mode 2
H
43 Ultra DMA mode 3
H
44 Ultra DMA mode 4
H
45 Ultra DMA mode 5
H
46 Ultra DMA mode 6
H
10 Enable use of SATA features
H
02 DMA Setup FIS Auto-Activate optimization
H
03 Device-initiated interface power state transitions
H
06 Software Settings Preservation
H
55 Disable read look-ahead (read cache) feature
H
66 Disable reverting to power-on defaults
H
82 Disable write cache
H
90 Disable use of SATA features
H
02 DMA Setup FIS Auto-Activate optimization
H
03 Device-initiated interface power state transitions
H
06 Software Settings Preservation
H
AA Enable read look-ahead (read cache) feature (default).
H
CC Enable reverting to power-on defaults
H
At power-on, or after a hardware or software reset, the default values of the features are as
Note.
indicated above.
Pulsar.2 Product Manual, Rev. A 39