System information

AlphaServer 800 Service Guide
5-4
System Machine Check (SCB: 660)
A system machine check is a system- or processor-detected error that occurred as a
result of an “off-chip” request to the system. The following conditions cause
PALcode to build the 660/670 machine check logout frame and invoke the 660 error
handler.
• CIA-detected noncorrectable ECC error
• CIA-detected command/address parity error
• CIA-detected nonexistent memory reference
• PCI bus parity error
• PCI command/address parity error
• PCI master abort
• PCI target abort
• Scatter/gather invalid translations table entry
• I/O timeout
• System overtemperature (event)
• Unexpected IPL 23 interrupt request
Processor-Detected Correctable Errors (SCB: 630)
Processor-detected correctable errors are generic Alpha 21164A microprocessor
correctable errors. The error-handling code should be common across all platforms
that use the Alpha 21164A. The following conditions cause PALcode to invoke the
operating system 630 error handler:
• Single-bit I-stream ECC error
• Single-bit D-stream ECC error
System-Detected Nonfatal Error (SCB: 620)
These nonfatal errors are AlphaServer 800-specific correctable errors. The following
conditions cause the PALcode to invoke the operating system 620 error handler:
• DMA read errors
• High temperature warning (event)
• Fan warning/failure (event)—This event is fatal and noncorrectable, though
reported as nonfatal. The OS then shuts the system down.