BDM-610000050 Rev A Chapter 4: Using the cpuModule 55
Hardware Interrupts
The CMX58886CX cpuModule supports the standard PC interrupts listed in Table38. Interrupts not in use by
hardware on the cpuModule itself are listed as available. Similarly, if the operating system is using APIC, more
IRQs will be available.
For external devices that require Legacy/ISA interrupts , a serial interrupt signal is available which permits access
to the CPU’s hardware interrupts. One pair of Legacy/ISA DMA request/grant signals are also available. For more
information on the serial interrupt signal, and the DMA request/grand pair, refer to Bridge Link (CN4) in
Chapter3, Connecting the cpuModule
Note If you add any expansion modules or other peripherals to the system, you must ensure they do not
use interrupts needed by the cpuModule, or malfunctions will occur.

Table 38 Hardware Interrupts Used on the CMX58886CX cpuModule

Interrupt Normal Use
0Timer 0
1Keyboard
2 Cascade of IRQ 8–15
3COM2
4COM1
5 Available
61
1. Floppy disk interrupt, INT6, is available for use if no floppy
disk is present in the system and floppy disk is disabled in
Setup.
Floppy
7Printer
8Real Time Clock
9 Available, routed to IRQ 2
10 Available
11 Available
12 Bus Mouse
142
2. Hard disk interrupt , INT14, is availa ble for u se if no h ard disk
drive is present in the system and hard disk is disabled in
Setup.
Primary IDE hard disk3
3. IRQs 14 and 15 may be available if the IDE controller is
configured in Native Mode (refer to IDE Controller
Configuration—page 61)
15 ATA/IDE Disk Chip socket
Note The cpuModule has onboard PCI devices that will claim IRQ lines. In some instances, a PCI device
will claim an IRQ line that is re quired b y a lega cy devi ce. To reser ve an IRQ for a leg acy de vice, re fer to t he
PnP/PCI Configuration Setup fields in the BIOS.