Chapter 3
Hardware
CoreModule 720
Reference Manual
21
Interrupt Channel Assignments
The interrupt channel assignments are shown in
Table 3-1
.
Legend:
D = Default, O = Optional, X = Fixed
Memory Map
The following table provides the common PC/AT memory allocations. These are DOS-level addresses. The
OS typically hides these physical addresses by way of memory management.
Table 3-1. Interrupt Channel Assignments
Device vs IRQ No.
0
1
2
3
4
5
6
7
8
9
10 11
12
13
14
15
Timer X
Secondary Cascade
X
COM0
O D
COM1
D O
COM2
O
D
COM3
O O
D
O
RTC
X
Math Coprocessor
X
PCI INTA
Automatically Assigned
PCI INTB
Automatically Assigned
PCI INTC
Automatically Assigned
PCI INTD
Automatically Assigned
USB
Automatically Assigned
Video
Automatically Assigned
NOTE
The IRQs for USB and Video are automatically assigned by the BIOS Plug and
Play logic. Local IRQs assigned during initialization can not be used by external
devices.
Table 3-2. Memory Map
Base Address
Function
00000000h - 0009FFFFh
Conventional Memory
000A0000h - 000AFFFFh
Graphics Memory
000B0000h -
000B7FFFh
Mono Text Memory
000B8000h -
000BFFFFh
Color Text Memory
000C0000h -
000CFFFFh
Standard Video BIOS
000D0000h - 000DFFFFh
DVMT Memory
000E0000h -
000EFFFFh
PCI Express Base Memory
000F0000h -
000FFFFFh
System Flash and PCI Resources