Owner`s manual

4.4 Machine Checks
A machine check exception is reported through SCB vector 04 (hex) whenan
error condition is detected. The frame pushed on the stack for a machine
check indicates the type of error and provides internal state information
that helps to identify the cause of the error. The machine check stack frame
is shown in Figure 4–64 and its parameters are described in Table 4–5.
Table 4–6 lists and describes the machine check codes.
Software must acknowledge machine checks by writing a zero to IPR38,
MCESR, as a second machine check causes an ERR_MCHK_MCHK console
halt.
Figure 4–64: Machine Check Stack Frame
3
1 1
Parameter Byte Count (18 hex) :SP
Machine Check Code
VA
VIBA
ICCS..SISR
Internal State
24 23 20 18 17 16 15 8 7 4 3
DELTA−PC AT DL RN
msb−p216−89
R
0
0
OPCODE
SC
Unused Unused
31 21
PC
PSL
4–36 VAX 6000 Model 500 Mini-Reference