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1 smi# priority, Table 73. relative priority of exceptions and int – Intel 386 User Manual

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7-7

SYSTEM MANAGEMENT MODE

7.3.2.1

SMI# Priority

When more than one exception or interrupt is pending at an instruction boundary, the processor
services them in a predictable order. The priority among classes of exception and interrupt sourc-
es is shown in Table 7-3. The processor first services a pending exception or interrupt from the
class that has the highest priority, transferring execution to the first instruction of the handler.
Lower priority exceptions are discarded; lower priority interrupts are held pending. Discarded ex-
ceptions are reissued when the interrupt handler returns execution to the point of interruption.
SMI# has the following relative priority, where 1 is highest and 11 is lowest:

Table 7-3. Relative Priority of Exceptions and Interrupts

1

(Highest priority)

Double Fault

2

Segmentation Violation

3

Page Fault

4

Divide-by-zero

5

SMI#

6

Single-step

7

Debug

8

ICE Break

9

NMI

10

INTR

11

(Lowest Priority)

I/O Lock