Technical data

CHALLENGE/Onyx Diagnostic Road Map 2-39
If you suspect this, check the termination voltage supplied by the System Controller. Use
the Voltage Status menu on the front panel. It should read 1.6 volts. If it does not, it is likely
that backplane voltage droop is causing the errors.
You can also use the sysctrlrd command to examine the voltages. Log in as root and enter
the following command from the shell prompt:
/usr/etc/sysctlrd -p
To resolve this problem and ensure reliable system operation, apply deviation DA798 to
increase the termination voltage for the System Controller. This deviation raises the
termination voltage from 1.5 volts to 1.6 volts.
2.7.9 MC3 SIMM Failure
The following message is a sign of possible MC3 SIMM failure:
HARDWARE ERROR STATE:
+ MC3 in slot 1
+ MA EBus Error register: 0x4
+ 2: My EBus Data Error
+ MA Leaf 1 Error Status Register: 0x2
+ 1: Read Uncorrectable (Multiple Bit) Error
+ MA Leaf 1 Bad Memory Address: 0x1df47b80
+ IP19 in slot 2
+ CC in IP19 Slot 2, cpu 3
+ CC ERTOIP Register: 0x10
+ 4:Parity Error on Data from D-chip
The MC3 is showing Read Uncorrectable (Multiple Bit) Error, meaning the MC3
had an ECC error in its SIMM and therefore purposely encoded a response to the IP19 with
parity error set. Therefore, the IP19 error message Parity Error on Data from D-chip
is a result of the MC3 ECC problem and so is the MC3 My EBus Data Error. The ECC in
the MC3 SIMM is the problem.
2.7.10 VME Bus Error on PIO Read
Occasionally there is a VME bus error on a PIO read. It occurs when a driver performs a
PIO read on a VME device that does not respond. The VME bus times out, and the
following error message is displayed: