Vol. 3A 6-51

INTERRUPT AND EXCEPTION HANDLING

Interrupts 32 to 255—User Defined Interrupts

Exception Class

Not applicable.

Description

Indicates that the processor did one of the following things:

•

Executed an INT n instruction where the instruction operand is one of the vector numbers from 32 through 255.

•

Responded to an interrupt request at the INTR pin or from the local APIC when the interrupt vector number 
associated with the request is from 32 through 255.

Exception Error Code

Not applicable.

Saved Instruction Pointer

The saved contents of CS and EIP registers point to the instruction that follows the INT n instruction or instruction 
following the instruction on which the INTR signal occurred.

Program State Change

A program-state change does not accompany interrupts generated by the INT n instruction or the INTR signal. The 
INT n instruction generates the interrupt within the instruction stream. When the processor receives an INTR 
signal, it commits all state changes for all previous instructions before it responds to the interrupt; so, program 
execution can resume upon returning from the interrupt handler.