Intel Desktop Board D945PLRN Technical Product Specification
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2.4 Interrupts
The interrupts can be routed through either the Programmable Interrupt Controller (PIC) or the
Advanced Programmable Interrupt Controller (APIC) portion of the ICH7 component. The PIC is
supported in Windows 98 SE and Windows ME and uses the first 16 interrupts. The APIC is
supported in Windows 2000 and Windows XP and supports a total of 24 interrupts.
Table 12. Interrupts
IRQ System
Resource
NMI
I/O channel check
0
Reserved, interval timer
1
Reserved, keyboard buffer full
2
Reserved, cascade interrupt from slave PIC
3 User
available
4 COM1
(Note 1)
5 User
available
6 Diskette
drive
7 LPT1
(Note 1)
8 Real-time
clock
9 User
available
10 User
available
11 User
available
12
Onboard mouse port (if present, else user available)
13
Reserved, math coprocessor
14
Primary Parallel ATA/Serial ATA – Legacy Mode (if present, else user available)
15
Secondary Parallel ATA/Serial ATA – Legacy Mode (if present, else user available)
16
(Note 2)
User available (through PIRQA)
17
(Note 2)
User available (through PIRQB)
18
(Note 2)
User available (through PIRQC)
19
(Note 2)
User available (through PIRQD)
20
(Note 2)
User available (through PIRQE)
21
(Note 2)
User available (through PIRQF)
22
(Note 2)
User available (through PIRQG)
23
(Note 2)
User available (through PIRQH)
Notes:
1. Default, but can be changed to another IRQ.
2. Available in APIC mode only.
