1-4 Technical Information
INTERRUPT CONTROLLER
The interrupt controller operates as an interrupt manager for the entire AT system
environment. The 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 Table 1-3. Interrupt-level assignments 0 through 15 are
in order of decreasing priority. See Section 2 of the PowerMate Ve Series Service and
Reference Manual for information on changing the interrupts using Setup.
Table 1-3 Interrupt Level Assignments
Interrupt
Assignment
IRQ 0
Counter/Timer
IRQ 1
Keyboard
IRQ 2(9)
Cascade (INT output from slave)
IRQ 3
COM2 and COM4
IRQ 4
COM1 and COM3
IRQ 5
Parallel Port 2/Audio (if present)
IRQ 6
Diskette Drive Controller
IRQ 7
Parallel Port 1
IRQ 8
Real-time clock
IRQ 10
Available/Audio (if present)
IRQ 11
Network Interface Board
IRQ 12
PS/2 mouse
IRQ 13
Coprocessor
IRQ 14*
Primary IDE
IRQ 15*
Secondary IDE
