User Manual

ATA Command Description

CompactFlash

5.1.16. Seek—7XH

Table 5-20. Seek

Bit -> 7 6 5 4 3 2 1 0

Command (7) 7XH

C/D/H (6) 1 LBA 1 Drive Head (LBA 27-24)

Cyl High (5) Cylinder High (LBA 23-16)

Cyl Low (4) Cylinder Low (LBA 15-8)

Sec Num (3) X (LBA 7-0)

Sec Cnt (2) X

Feature (1) X

This command is effectively a NOP command to the CompactFlash Memory Card although it does perform a range

check of cylinder and head or LBA address and returns an error if the address is out of range.

5.1.17. Set Features—EFH

Table 5-21. Seat Features

Bit -> 7 6 5 4 3 2 1 0

Command (7) EFH

C/D/H (6) X Drive X

Cyl High (5) X

Cyl Low (4) X

Sec Num (3) X

Sec Cnt (2) Config

Feature (1) Feature

This command is used by the host to establish or select certain features. Table 5-22 defines all features that are

supported. Please note that the 9AH feature is unique to the CompactFlash Memory Card and are not part of the

ATA Specification.

Table 5-22. Features Supported

Feature

Operation

01H Enable 8-bit data transfer.

03H Set Transfer Mode based on value and Sector Count register.

55H Disable Read Look Ahead.

66H Disable Power on Reset (POR) establishment of defaults at Soft Reset.

69H Accepted for backward compatibility with the SDP Series but has no impact on the CF Memory Card.

81H Disable 8-bit data transfer.

96H Accepted for backward compatibility with the SDP Series but has no impact on the CF Memory Card.

9AH Accepted for backward compatibility with the SDP Series but has no impact on the CF Memory Card.

BBH 4 bytes of data apply on Read/Write Long commands.

CCH Enable Power on Reset (POR) establishment of defaults at Soft Reset.