Transcend Information TS32M~1GCF80

80X CompactFlash Card

Transcend Information Inc.

Bit 4 (-HS2): this bit is the negation of bit 2 in the Drive/Head register.

Bit 3 (-HS1): this bit is the negation of bit 1 in the Drive/Head register.

Bit 2 (-HS0): this bit is the negation of bit 0 in the Drive/Head register.

Bit 1 (-nDS1): this bit is 0 when drive 1 is active and selected.

Bit 0 (-nDS0): this bit is 0 when the drive 0 is active and selected.

5.6 CF-ATA Command Description

This section defines the software requirements and the format of the commands the host sends to the CompactFlash

Storage Cards. Commands are issued to the CompactFlash Storage Card by loading the required registers in the

command block with the supplied parameters, and then writing the command code to the Command Register. The

manner in which a command is accepted varies. There are three classes (see Table 38: CF-ATA Command Set) of

command acceptance, all dependent on the host not issuing commands unless the CompactFlash Storage Card is not

busy (BSY=0). All commands listed in this specification shall be implemented.

 Upon receipt of a Class 1 command, the CompactFlash Storage Card sets BSY within 400 nsec.

 Upon receipt of a Class 2 command, the CompactFlash Storage Card sets BSY within 400 nsec, sets up the sector

buffer for a write operation, sets DRQ within 700 µsec, and clears BSY within 400 nsec of setting DRQ.

 Upon receipt of a Class 3 command, the CompactFlash Storage Card sets BSY within 400nsec, sets up the sector

buffer for a write operation, sets DRQ within 20 msec (assuming no re-assignments), and clears BSY within 400

nsec of setting DRQ.