User Manual

CompactFlash

5. ATA Command Description

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

Memory Cards. Commands are issued to the CompactFlash 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 5-1) of command acceptance, all dependent

on the host not issuing commands unless the CompactFlash Card is not busy. (The BUSY bit in the status and

alternate status registers is 0.)

•

Upon receipt of a Class 1 command, the CompactFlash Card sets the BUSY bit within 400 nsec.

•

Upon receipt of a Class 2 command, the CompactFlash Memory Card sets the BUSY bit within 400

nsec, sets up the sector buffer for a write operation, sets DRQ within 700 µsec, and clears the BUSY

bit within 400 nsec of setting DRQ.

•

Upon receipt of a Class 3 command, the CompactFlash Memory Card sets the BUSY bit within 400

nsec, sets up the sector buffer for a write operation, sets DRQ within 20 msec (assuming no re-

assignments), and clears the BUSY bit within 400 nsec of setting DRQ.

5.1. ATA Command Set

Table 5-1 summarizes the ATA command set with the paragraphs that follow describing the individual commands

and the task file for each.

Table 5-1. ATA Command Set

Class COMMAND Code FR SC SN CY DH LBA

1 Check Power Mode E5h or 98h - - - - D -

1 Execute Drive Diagnostic 90h - - - - D -

1 Erase Sector(s) (Note 2) C0h - Y Y Y Y Y

2 Format Track 50h - Y - Y Y Y

1 Identify Drive ECh - - - - D -

1 Idle E3h or 97h - Y - - D -

1 Idle Immediate E1h or 95h - - - - D -

1 Initialize Drive Parameters 91h - Y - - Y -

1 Read Buffer E4h - - - - D -

1 Read Multiple C4h - Y Y Y Y Y

1 Read Long Sector 22h or 23h - - Y Y Y Y

1 Read Sector(s) 20h or 21h - Y Y Y Y Y

1 Read Verify Sector(s) 40h or 41h - Y Y Y Y Y

1 Recalibrate 1Xh - - - - D -

1 Request Sense (Note 1) 03h - - - - D -

1 Seek 7Xh - - Y Y Y Y

1 Set Features EFh Y - - - D -

1 Set Multiple Mode C6h - Y - - D -

1 Set Sleep Mode E6h or 99h - - - - D -

1 Stand By E2h or 96h - - - - D -

1 Stand By Immediate E0h or 94h - - - - D -