Machine Checks/Interrupts - Compaq AlphaServer ES45 Service Manual

5.3

Machine Checks/Interrupts

The exceptions that result from hardware system errors are called
machine checks/interrupts. They occur when a system error is detected
during the processing of a data request.
During the error-handling process, errors are first handled by the appropriate
PALcode error routine and then by the associated operating system error
handler. PALcode transfers control to the operating system through the PAL
handler.
Table 5–3 lists the machine checks/interrupts that are related to error events.
The designations — 630, 670, 620, 660, and 680 — indicate a system control
block (SCB) offset to the fatal system error handler for Tru64 UNIX and
OpenVMS.
Table 5–3 Machine Checks/Interrupts
Error Type
CPU Correctable Error (630)
Generic Alpha 21264 (EV68 )
correctable errors.
CPU Uncorrectable Error
(670)
Fatal microprocessor
machine check errors that
result in a system crash.
Error Descriptions
B-cache probe hit single-bit ECC error
D-cache tag parity error on issue
I-cache tag or data parity error
D-cache victim single-bit ECC error
B-cache single-bit ECC fill error to I-stream or D-stream
Memory single-bit ECC fill error to I-stream or D-
stream
PAL detected bugcheck error
Operating system detected bugcheck error
EV68 detected second D-cache store EEC error
EV68 detected D-cache tag parity error in pipeline 0 or 1
EV68 detected duplicate D-cache tag parity error
EV68 detected double-bit ECC memory fill error
EV68 detected double-bit probe hit EEC error
EV68 detected B-cache tag parity error
Error Logs 5-19