Set Features Command - Seagate BARRACUDA XT SERIES SATA ST32000641AS 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 com-
mand, it sets BSY, checks the contents of the Features register, clears BSY and generates an interrupt. 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 7: 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
55 Disable read look-ahead (read cache) feature.
H
82 Disable write cache
H
90 Disable use of SATA features
H
AA Enable read look-ahead (read cache) feature (default).
H
F1 Report full capacity available
H
Note. At power-on, or after a hardware or software reset, the default values of the features are as indicated above.
Barracuda XT Series SATA Product Manual, Rev. C 27