Service manual

Error Logs 5-11
5.3 Error Log Examples and Analysis
The following sections provide examples and analysis of error logs.
5.3.1 MCHK 670 CPU-Detected Failure
The error log in Example 5-1 shows the following:
➊ CPU1 logged the error in a system with two CPUs.
➋ During a D-ref fill, the External Interface Status Register logged an
uncorrectable EEC error. (When a CPU chip does not find data it needs to
perform a task in any of its caches, it requests data from off the chip to fill
its D-caches. It performs a “D-ref fill.”) Bit<30> is clear, indicating that
the source of the error is the B-cache.
➌ Neither IOD CAP Error Register saw an error.
The error was detected by a CPU and the data was not on the system bus.
Otherwise, the IODs would have seen the error. Therefore, CPU1 is broken.
NOTE: The error log example has been edited to decrease its size; registers of
interest are in bold type. The “Horse” module referred to in the error log is the
system bus to PCI bus bridge module, the B3040 module. The “Saddle” module is
the PCI motherboard, the B3050 module. The “MC” bus is the system bus.
Refer to Table 5-9 for information on decoding commands, and refer to Table 5-10
for information on node IDs.