Fujitsu MPB3052AT User Manual download pdf (Page 102)

C141-E045-02EN 5 - 37

(16) 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 1 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.

Table 5.6 Diagnostic code

Code Result of diagnostic

X‘01’

X‘03’

X‘05’

X‘8x’

No error detected.

Data buffer compare error

ROM sum check error

Failure of device 1

1 2 ... 97 98 99 100 101 102 103 104 105 106 107 ... 179 180

No comments

Fujitsu MPB3052AT User Manual Page 102