IBM IC25N020ATDA04 - Travelstar 20 GB Hard Drive - Diagnostic and Reset Considerations; Figure 62. Reset Error Register Values

11.2 Diagnostic and Reset considerations
The Set Max password, the Set Max security mode and the Set Max unlock counter are not retained over
a Power On Reset but are retained over a Hard Reset or Soft Reset.
For each Reset and Execute Device Diagnostic, the diagnostic is done as follows:
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
that the device is 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 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.
Soft 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 activi-
ty. If Device 1 is not present, Device 0 does not Assert DASP- at POR.
Power On Reset, Hard Reset
In each case—Power On Reset [Hard Reset], Soft Reset, and the Execute Device Diagnostic
command—the Device 0 Error register value is interpreted using the table below.
0xh
No
(not read)
No
01h
Yes
(not read)
No
8xh
No
No
Yes
81h
Yes
No
Yes
0xh
No
Yes
Yes
01h
Yes
Yes
Yes
Error
Register
Device 0
Passed
PDIAG-
Asserted?
Device 1
present?
Figure 62. Reset error register values
The "x" indicates the appropriate Diagnostic Code for the Power on, RESET-, Soft Reset, or Device
Diagnostic error.
Travelstar 48GH, 30GN & 15GN hard disk drive specifications
80