I/O Address Space; I/O Channel Check; Irq; Irq15 - American Megatrends Apollo User Manual

Onboard I/O Support,

Memory Addresses

the PCI expansion slots. The ISA expansion slots use the 16-bit memory addresses to access up to 16 MB.

I/O Channel Check

I/O Address Space

compatible I/O.
Seven DMA Channels
device sizes.
Fifteen Interrupt Levels
Priority Label Typical Interrupt Source
1

IRQ 0

Interval Timer 1, Counter 0 OUT
2 IRQ 1

Keyboard

3-10 IRQ 2 Used internally for IRQ 8 through IRQ 15
3 IRQ 8 Real-Time-Clock
4 IRQ 9 PCI/PnP or ISA
5 IRQ 10 PCI/PnP or ISA
6 IRQ 11 PCI/PnP or ISA
7 IRQ 12 Onboard PS/2 Mouse or PCI/PnP or ISA
8 IRQ 13 Coprocessor Error (internal)
9 IRQ 14 Hard disk drive, local bus IDE controller, or
PCI/PnP. or ISA
10 IRQ 15 PCI/PnP or ISA
11 IRQ 3 Serial Port 2, PCI/PnP, or ISA
12 IRQ 4 Serial Port 1, PCI/PnP, or ISA
13 IRQ 5 Parallel Port 2, PCI/PnP or ISA
14 IRQ 6 Floppy disk controller
15 IRQ 7 Parallel Port 1, PCI/PnP or ISA
8
Continued
The motherboard uses 32-bit memory addresses to access 4 gigabytes of memory address space on
The motherboard supports the use of the I/O channel check to generate NMIs.
The Apollo Pentium PCI motherboard uses I/O addresses 0100h through 03FFh for ISA-
The motherboard has seven DMA channels. Any DMA channel can be set for 8 or 16-bit DMA
The NMI takes precedence over all 15 hardware interrupts.
Apollo Motherboard User's Guide