5.3.2Set 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

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

55H

Disable read look-ahead (read cache) feature.

82H

Disable write cache

AAH

Enable read look-ahead (read cache) feature (default).

F1H

Report full capacity available

Note. At power-on, or after a hardware or software reset, the default values of the features are as indi- cated above.

5.3.3S.M.A.R.T. commands

S.M.A.R.T. provides near-term failure prediction for disc drives. When S.M.A.R.T. is enabled, the drive moni- tors predetermined drive attributes that are susceptible to degradation over time. If self-monitoring determines that a failure is likely, S.M.A.R.T. makes a status report available to the host. Not all failures are predictable. S.M.A.R.T. predictability is limited to the attributes the drive can monitor. For more information on S.M.A.R.T. commands and implementation, see the Draft ATA-8 Standard.

28

Momentus XT Product Manual, Rev. D

Page 34
Image 34
Seagate ST750LX003, 100665905, ST500LX003 manual Set Features command values, 3 S.M.A.R.T. commands