5. Advanced Interrupt Controller (AIC)

The core features of the Advanced Interrupt Controller are:

  • 32 Internal or External Interrupt Sources

  • 8-level Priority Controller

  • Level Sensitive or Edge Triggered

  • Programmable Polarity for External Sources

Moreover, all PIO lines can be used to generate a PIO interrupt. However, the PIO lines can only generate level change interrupts, that is, positive as well as negative edges will generate an interrupt. The PIO interrupt itself (PIO to AIC line) is usually programmed to be level-sensitive. Otherwise interrupts will be lost if multiple PIO lines source an interrupt simultaneously.

On the Stamp9G20 IRQ0, IRQ2 and the FIQ are available. The list of peripheral identifiers, which are used to program the AIC can be found in Table B.1, “Peripheral Identifiers”