ADLINK PCI-7396 - Manual (Page 35)

Operation Theorem
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4.3.3 Dual Interrupt System
The PCI controller can receive two hardware IRQ requests. However, only
one IRQ will be sent to PCI bus, the two IRQ requests must be
distinguished by user’s interrupt service routine (ISR).
The two IRQ requests are named as INT1 and INT2. INT1 comes from COS
P1 & P2, P1C0, P1C3, or the event counter interrupt. INT2 comes from
COS P3 & P4, P2C0, P2C3, or the timer interrupt. The sources of INT1 and
INT2 is selectable by using the Interrupt Source Control (ISC) Register.
Figure 4.4 Dual Interrupt System of PCI-7396
PCI
Controller
INT #A
IRQ
Flip-
Flops
INT1
INT2
INT1
MUX
P1C0/~P1C3
COS P1 & P2
Event IRQ
P2C0/~P2C
COS P3 & P4
Timer IRQ
~P1C0
~P2C0
INT2
MUX
Clear IRQ