www.seagate.com

Serial ATA Interface

Table 9 Bit Descriptions (continued)

 

 

6

Ultra DMA mode 6 is supported.

8Ultra DMA mode 0 is currently active.

9Ultra DMA mode 1 is currently active.

10Ultra DMA mode 2 is currently active.

11Ultra DMA mode 3 is currently active.

12Ultra DMA mode 4 is currently active.

13Ultra DMA mode 5 is currently active.

14Ultra DMA mode 6 is currently active.

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 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 10 Set Features command values

02H

Enable write cache (default).

03H

Set transfer mode (based on value in Sector Count register).

 

Sector Count register values:

 

 

 

00H Set PIO mode to default (PIO mode 2).

 

01H Set PIO mode to default and disable IORDY (PIO mode 2).

 

08H PIO mode 0

 

09H PIO mode 1

 

0AH PIO mode 2

 

0BH PIO mode 3

 

0CH PIO mode 4 (default)

 

20H Multiword DMA mode 0

 

21H Multiword DMA mode 1

 

22H Multiword DMA mode 2

 

40H Ultra DMA mode 0

 

41H Ultra DMA mode 1

 

42H Ultra DMA mode 2

 

43H Ultra DMA mode 3

 

44H Ultra DMA mode 4

 

45H Ultra DMA mode 5

 

46H Ultra DMA mode 6

06H

Enable the PUIS feature set,

Video 3.5 HDD Product Manual, Rev. H

37

Page 37
Image 37
Seagate ST4000VM000 manual Set Features command, Ultra DMA mode 6 is supported