Fujitsu MHJ2181AT, MHK2120AT, MHK2090AT, MHK2060AT manual Execute Device Diagnostic X’90’

Interface

At command completion (I/O registers contents to be read)

1F7H(ST)	Status information
1F6H(DH)	×	×	×	DV	Max head/LBA [MSB]
1F5H(CH)	Max. cylinder [MSB]/Max. LBA
1F4H(CL)	Max. cylinder [LSB]/Max. LBA
1F3H(SN)	Max. sector/Max. LBA [LSB]
1F2H(SC)	xx
1F1H(ER)	Error information

(18) EXECUTE DEVICE DIAGNOSTIC (X’90’)

This command performs an internal diagnostic test (self-diagnosis) of the device. This command usually sets the DRV bit of the Drive/Head register is to 0 (however, the DV bit is not checked). If two devices are present, both devices execute self-diagnosis.

If device 1 is present:

∙

∙

∙

∙

∙

Both devices shall execute self-diagnosis.

The device 0 waits for up to 5 seconds until device 1 asserts the PDIAG- signal.

If the device 1 does not assert the PDIAG- signal but indicates an error, the device 0 shall append X’80’ to its own diagnostic status.

The device 0 clears the BSY bit of the Status register and generates an interrupt. (The device 1 does not generate an interrupt.)

A diagnostic status of the device 0 is read by the host system. When a diagnostic failure of the device 1 is detected, the host system can read a status of the device 1 by setting the DV bit (selecting the device 1).

When device 1 is not present:

∙

∙

The device 0 posts only the results of its own self-diagnosis.

The device 0 clears the BSY bit of the Status register, and generates an interrupt.

Table 5.6 lists the diagnostic code written in the Error register which is 8-bit code.

If the device 1 fails the self-diagnosis, the device 0 “ORs” X’80’ with its own status and sets that code to the Error register.

5-46 C141-E088-01EN