Advantech ADAM-5240, Руководство пользователя

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23 Chapter 2
2.12 Interrupt Setting
When the interrupt occurs from MCX314AS, the interrupt signal of
MCX314AS will be changed from high to low. Because the PCI bus
interrupt is high level sensitive, the ADAM-5240 inverse the signal and
latch the signal to adapt the PCI bus INTA. The Fig- 3.17 shows the inter-
rupt structure of the ADAM-5240. We suggest users who want to pro-
gram their own interrupt service routine (ISR) should follow the
procedures:
Step 1: When interrupt occurs. (Hardware)
Step 2: Program will jump to ISR. (Software)
Step 3: In ISR program the first thing have to do is clear interrupt for pre-
venting hanging up the PCI bus.
Step 4: In ISR program the last thing have to do is read nRR3 of
MCX314AS for accepting next interrupt occurs.
Figure 2.16: Circuit Diagram of Interrupt Setting