2.5.3 I
nterrupt assi
gnments
Standard i
nterrupt assi
gnments
IRQ | Priority | Standard Function |
|
0 | 1 | System Timer |
|
1 | 2 | Keyboard Controller |
|
2 | — |
| |
3* | 11 | Communications Port (COM2) |
|
4* | 12 | Communications Port (COM1) |
|
5* | 13 | IRQ holder for PCI steering |
|
6 | 14 | Floppy Disk Controller |
|
7* | 15 | Printer Port (LPT1) |
|
8 | 3 | System CMOS/Real Time Clock |
|
9* | 4 | IRQ holder for PCI steering |
|
10* | 5 | IRQ holder for PCI steering |
|
11* | 6 | IRQ holder for PCI steering |
|
12* | 7 | PS/2 Compatible Mouse Port |
|
13 | 8 | Numeric Data Processor |
|
14 | 9 | Primary IDE Channel |
|
15 | 10 | Secondary IDE Channel |
|
* These IRQs are usually available for ISA or PCI devices.
PCI
Bus Number, I
DSEL,
and I
RQ assi
gnments
Description | INTA INTB | INTC | INTD | REQ# | GNT# |
| |
|
|
|
|
|
|
|
|
PATA Controller | PIRQA# | — | — | — | — | — |
|
SATA Controller | PIRQD# | — | — | — | — | — |
|
SMBus Controller | PIRQB# | — | — | — | — |
|
|
USB1 UHCI Controller #1 | PIRQH# | — | — | — | — |
|
|
USB1 UHCI Controller #2 | PIRQD# | — | — | — | — | — |
|
USB 2.0 EHCI Controller | PIRQH# | — | — | — | — | — |
|
BMC5721 #1 | PIRQA# | — | — | — | — | — |
|
BMC5721 #2 | PIRQB# | — | — | — | — | — |
|
ATI RAGE XL | PIRQD# | — | — | — | REQ1# | GNT1# |
|
Adaptec 7901 | PXIRQ2 | — | — | — | PXREQ2 | PXGNT2 |
|
PCI Express Slot 1 (x16) | PIRQA# | — | — | — | — | — |
|
PCIX Slot 2 | PXIRQ0 | PXIRQ1 | PXIRQ2 | PXIRQ3 | PXREQ0 | PXGNT0 |
|
PCIX Slot 3 | PXIRQ4 | PXIRQ5 | PXIRQ6 | PXIRQ7 | PXREQ1 | PXGNT1 |
|
PCI Slot 4 | PIRQE# | PIRQF# | PIRQG# | PIRQH# | REQ0# | GNT0# |
|
Chapter 2: Hardware information |