Intel 253668-032US User Manual
6-16 Vol. 3
INTERRUPT AND EXCEPTION HANDLING
“Returning from a Called Procedure”). If index points to a task gate, the processor
executes a task switch to the exception- or interrupt-handler task in a manner similar
to a CALL to a task gate (see Section 7.3, “Task Switching”).
executes a task switch to the exception- or interrupt-handler task in a manner similar
to a CALL to a task gate (see Section 7.3, “Task Switching”).
6.12.1
Exception- or Interrupt-Handler Procedures
An interrupt gate or trap gate references an exception- or interrupt-handler proce-
dure that runs in the context of the currently executing task (see Figure 6-3). The
segment selector for the gate points to a segment descriptor for an executable code
segment in either the GDT or the current LDT. The offset field of the gate descriptor
points to the beginning of the exception- or interrupt-handling procedure.
dure that runs in the context of the currently executing task (see Figure 6-3). The
segment selector for the gate points to a segment descriptor for an executable code
segment in either the GDT or the current LDT. The offset field of the gate descriptor
points to the beginning of the exception- or interrupt-handling procedure.
Figure 6-3. Interrupt Procedure Call
IDT
Interrupt or
Code Segment
Segment Selector
GDT or LDT
Segment
Interrupt
Vector
Base
Address
Address
Destination
Procedure
Interrupt
+
Descriptor
Trap Gate
Offset