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.

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Seagate ST9640424AS, ST9750422AS, ST9750424AS, ST9750423ASG, ST9750420ASG, ST9640422AS Set Features command values
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ST9500428AS, ST9640422AS, ST9750423ASG, ST9750420AS, ST9750420ASG specifications

The Seagate ST9750422AS, ST9750423AS, ST9500423ASG, ST9640423ASG, and ST9500423AS are part of Seagate's popular lineup of SATA hard drives designed for consumer and enterprise applications. These drives are recognized for their reliability, performance, and advanced technologies, making them suitable for a variety of storage needs.

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