Reviewing System Features 3-5Interrupt ControllerThe interrupt controller operates as an interrupt managerfor the entire system environment. The controller acceptsrequests from peripherals, issues interrupt requests to theprocessor, resolves interrupt priorities, and provides vectorsfor the processor to determine which interrupt routine toexecute. The interrupt controller has priority assignmentmodes that can be reconfigured at any time during systemoperations.The interrupt levels are described in the following table.Interrupt-level assignments 0 through 15 are in order ofdecreasing priority. See “The Setup Utility” in Chapter 2for information on changing the interrupts using the Setuputility.Interrupt Level AssignmentsINTERRUPT PRIORITY INTERRUPT DEVICEIRQ00 Counter/TimerIRQ01 KeyboardIRQ02 Cascade (INT output from slave)IRQ03 COM2 and COM4IRQ04 COM1 and COM3IRQ05 Audio (if present)IRQ06 Diskette Drive ControllerIRQ07 Parallel Port 1IRQ08 Real-time clockIRQ09 S3 Video and USBIRQ10 AvailableIRQ11 AvailableIRQ12 PS/2 mouse
