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Interrupt Handling
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4-7
4
The assignments of the PCI and ISA interrupts supported by the PIB are as
follows:
Notes
1. Internally generated by the PIB.
2. Bit 4 of ISA Clock Divisor Register in the PIB must be set to 0 to
support external keyboard interrupt (from the ISASIO device).
Table 4-4. PIB PCI/ISA Interrupt Assignments
PRI
ISA
IRQ
PCI
IRQ
Co
n
tr
o
ll
er
Edge
/Leve
l
Po
la
ri
ty
Interrupt Source
No
te
s
1
IRQ0
INT1
Edge
High
Timer 1 / Counter 0
2
IRQ1
Edge
High
Keyboard
3-10
IRQ2
Edge
High
Cascade Interrupt from INT2
3
IRQ8_
INT2
Edge
Low
ABORT Switch Interrupt
4
IRQ9
Level
High
Z8536 CIO
Z85230 ESCC
5
IRQ10
PIRQ0_
Level
Low
PCI-Ethernet Interrupt
6
IRQ11
Level
Low
Not Used
7
IRQ12
Edge
High
Mouse
8
IRQ13
Edge
High
Not Used
9
IRQ14
PIRQ2_
Level
Low
PCI-SCSI Interrupt
10
IRQ15
PIRQ3_
Level
Low
PMC Interrupt
11
IRQ3
INT1
Edge
High
COM2 (Async Serial Port 2)
12
IRQ4
Edge
High
COM1 (Async Serial Port 1)
13
IRQ5
Level
High
Peripheral Parallel Port Interrupt
14
IRQ6
Edge
High
Floppy Interrupt
15
IRQ7
Edge
High
Host Parallel Port Interrupt