Set Features Command - Seagate Barracuda 5400.1 ST320015A Product Manual

34
4.1.3

Set Features command

This command (EF
drive supports. When the drive receives this command, 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:
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 (default)
H
0B PIO mode 3
H
0C PIO mode 4
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
05 Enable advanced power management
H
55 Disable read look-ahead (read cache) feature.
H
82 Disable write cache.
H
Barracuda 5400.1 Product Manual, Rev. A
) controls the implementation of various features that the
H