Reviewing System Interrupts B-1
Reviewing System
Interrupts
INTERRUPT CONTROLLER
The interrupt controller accepts requests from peripherals,
issues interrupt requests to the processor, resolves interrupt
priorities, and provides vectors for the processor to
determine which interrupt routine to execute. The interrupt
controller has priority assignment modes that can be
reconfigured at any time during system operations.
The interrupt levels are described in the following table.
Interrupt-level assignments 0 through 15 are in order of
decreasing priority. See Chapter 4, Setting System
Parameters, for information on changing the interrupts
using Setup.
Interrupt Level Assignments
INTERRUPT PRIORITY
INTERRUPT DEVICE
IRQ00
Counter/Timer
IRQ01
Keyboard
IRQ02
Cascade (INT output from slave)
IRQ03
COM2 and COM4
IRQ04
COM1 and COM3
IRQ05
Parallel Port 2/Audio (if present)
IRQ06
Diskette Drive Controller
IRQ07
Parallel Port 1
B
