Intel IA-32 - Manual (Page 191)

Vol. 3A 5-15
INTERRUPT AND EXCEPTION HANDLING
through Section 4.8.6, “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 6.3, “Task Switching”).
5.12.1 Exception- or Interrupt-Handler Procedures
An interrupt gate or trap gate references an exception- or interrupt-handler procedure that runs
in the context of the currently executing task (see Figure 5-3). 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 5-3. Interrupt Procedure Call
IDT
Interrupt or
Code Segment
Segment Selector
GDT or LDT
Segment
Interrupt
Vector
Base
Address
Destination
Procedure
Interrupt
+
Descriptor
Trap Gate
Offset