ATAPI Interface Chapter 5
Seagate Travan 40 Product Manual Page 95
EXECUTE DEVICE DIAGNOSTIC (ATA Command 90)
This command shall perform the internal diagnostic tests implemented by the device.
The DEV bit in the Device/Head register is ignored. Both devices, if present, shall
execute this command regardless of which device is selected.
If the Host issues an EXECUTE DEVICE DIAGNOSTIC command while a device is
in or going to a power management mode except Sleep, then the device shall
execute its EXECUTE DEVICE DIAGNOSTIC sequence.
Error information is returned as a diagnostic code in the Error register.
Host Taskfile Registers—Inputs
Data Bits
Host
Taskfile
Register
7 6 5 4 3 2 1 0 HEX
Features N/A N/A
Sector Count N/A N/A
Sector
Number N/A N/A
Byte Count
High N/A N/A
Byte Count
Low N/A N/A
Device/Head rsvd LBA rsvd DEV SAM LUN (not used)
Command command 90
Host Taskfile Registers—Outputs
Data Bits
Host
Taskfile
Register
7 6 5 4 3 2 1 0 HEX
Error diagnostic code (see below) 01
Sector Count ATAPI ‘signature’ 01
Sector
Number ATAPI ‘signature’ 01
Byte Count
High ATAPI ‘signature’ EB
Byte Count
Low ATAPI ‘signature’ 14
Device/Head ATAPI ‘signature’ 00
Status BSY RDY rsvd DSC DRQ Corr rsvd CHK 00