Appendix D. Interrupt Request And Direct Memory Access Channel Assignments - IBM NetVista User Manual

Appendix D. Interrupt request and direct memory access
channel assignments
The following tables list the IRQ and DMA channel assignments.
Note: The default settings for COM 1 (IRQ 4), COM 2 (IRQ 3), and LPT 1 (IRQ 7)
© Copyright IBM Corp. 2002
Table 4. IRQ channel assignment
IRQ System resource
NMI Critical system error
SMI System-management interrupt for power management
0 Timer
1 Keyboard
2 Cascade interrupt from slave PIC
3 COM2 (some models only)
4 COM1
5 Available to user
6 Diskette controller
7 LPT1
8 Real-time clock
9 Video, ACPI
10 Available to user
11 Available to user
12 Mouse port
13 Math coprocessor
14 Primary IDE (if present)
15 Secondary IDE (if present)
can be changed to another IRQ.
Table 5. DMA channel assignments
DMA Data width
0 8 bits
1 8 bits
2 8 bits
3 8 bits
4
5 16 bits
6 16 bits
7 16 bits
System resource
Open
Open
Diskette drive
Parallel port (for ECP or EPP)
Reserved (cascade channel)
Open
Open
Open
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