rtd cpuModule CMi36786HX, User Manual

Page: 73 / 116

CMi36786HX RTD Embedded Technologies, Inc.
65
Hardware Interrupts
The cpuModule supports the standard PC interrupts listed in Table 36 on page 65. Interrupts not in
use by hardware on the cpuModule itself are listed as 'available'. These interrupts are also assigned
by the BIOS to Plug and Play and PCI devices. Even if there are no PC/104-Plus modules installed,
the interrupts will be assigned to on board peripherals, such as USB or parallel ports. The BIOS can-
not automatically detect ISA bus (PC/104) cards that are using interrupts (including aDIO and the
Watchdog timer), so it may inadvertently assign another resource to an ISA interrupt. To prevent
this from happening, any interrupt that is being used for an ISA resource should be set to “Legacy
ISA” in the BIOS Setup utility under PnP/PCI configuration. See
PNP/PCI Configuration Setup
Fields on page 60 for details.
If you add any PC/104 modules or other peripherals to the
system you must ensure they
do not use interrupts needed
by the cpuModule, or malfunctions will occur
Table 36: Hardware Interrupts Used on the cpuModule
Interrupt Normal Use Source
0 Timer 0 On-board ISA device
1 Keyboard On-board ISA device
2 Cascade of IRQ 8-15 On-board ISA device
3 COM2 On-board ISA device
4 COM1 On-board ISA device
5 available XT bus
6
Floppy
a
a. IRQ6 is available for use if no floppy disk is present in the sys-
tem and floppy disk is disabled in Setup.
XT bus
7 Printer On-board ISA device
8 Real Time Clock On-board ISA device
9 available, routed to IRQ
2 XT bus
10 available AT bus
11 available AT bus
12
Bus mouse
b
b. IRQ12 is available if there is no PS/2 mouse in the system, and
the PS/2 mouse controller is disabled in the BIOS setup.
On-board ISA device
14
primary IDE hard disk
c AT bus
15 available
sometimes used as
secondary IDE hard disk AT bus