Diagnostic And Reset Considerations; Figure 76. Reset Error Register Values - IBM DTLA-305040 - Deskstar 41.1 GB Hard Drive Specifications

10.2 Diagnostic and reset considerations

For each Reset and Execute Device Diagnostic the diagnostic is done as follows:
Power On Reset
DASP- is read by Device 0 to determine if Device 1 is present. If Device 1 is present, Device 0
shall read PDIAG- to determine when it is valid to clear the BSY bit and whether Device 1 has
powered on or reset without error. Otherwise Device 0 clears the BSY bit whenever it is ready
to accept commands. Device 0 may assert DASP- to indicate device activity.
Hard Reset, Soft Reset
If Device 1 is present Device 0 shall read PDIAG- to determine when it is valid to clear the BSY
bit and whether Device 1 has reset without any errors. Otherwise Device 0 shall simply reset
and clear the BSY bit. DASP- is asserted by Device 0 (and Device 1 if it is present) in order to
indicate device active.
Execute Device Diagnostic
If Device 1 is present, Device 0 shall read PDIAG- to determine when it is valid to clear the BSY
bit and if Device 1 passed or failed the EXECUTE DEVICE DIAGNOSTIC command. Otherwise
Device 0 shall simply execute its diagnostics and then clear the BSY bit. DASP- is asserted by
Device 0 (and Device 1 if it is present) in order to indicate the device is active.
In all the above cases Power on, RESET-, Soft reset, and the EXECUTE DEVICE DIAGNOSTIC
command the Device 0 Error register as shown in the figure below.
Device 1
present? Asserted?
Yes
Yes
Yes
Yes
No (not read)
No (not read)
'x' indicates the appropriate Diagnostic Code for the Power on, RESET–, Soft Reset, or Device
Diagnostic error.

Figure 76. Reset error register values

PDIAG– Device 0
Passed
Yes Yes
Yes No
No Yes
No No
Yes
No
Deskstar 40GV & 75GXP hard disk drive specifications
Error
Register
01h
0xh
81h
8xh
01h
0xh
77