Datasheet

Execute Drive Diagnostic
This command performs self-diagnostics on various internal components of the card. Results of the test are reported
in the Error Register. Note that the bit definitions for the Error Register do not apply in this command; rather, the
value in the Error Register is a diagnostic code, defined in Table 1 below.
Execute Drive Diagnostics Command Issued by Host
Task File Register 7 6 5 4 3 2 1 0
COMMAND 90h
DRIVE/HEAD nu nu nu D nu
CYLINDER HI nu
CYLINDER LOW nu
SECTOR START nu
SECTOR COUNT nu
FEATURES nu
Command Block specified upon completion/termination of Execute Drive Diagnostics command (90h)
Task File Register 7 6 5 4 3 2 1 0
BSY DRDY DWF DSC DRQ CORR IDX ERR
STATUS 0 1 0 1 V V 0 V
DRIVE/HEAD na na na na na
CYLINDER HI na
CYLINDER LOW na
SECTOR na
SECTOR COUNT na
ERROR Diagnostic Code. See Table 1 below
Table 1. Execute Drive Diagnostic Return Codes
Code Description
01h No error detected
02h Formatter device error
03h Sector buffer error
04h ECC logic error
05h Controller microprocessor error