Keil™, An ARM® Company

MCBSTR9 User's Guide

Interrupt Functions

The STR91x devices provide support for handling interrupts from external and internal (on-chip) peripherals with its Vectored Interrupt Controller (VIC).

The VIC is responsible for:

  • Hardware handling of multiple interrupts
  • Arbitration of interrupt priorities
  • Interrupt vectorization

While most of the internal peripherals have their own interrupt vector and priority level, external peripherals (PIO, USB, software interrupt) share the same interrupt vector. The IRQ function for this vector is responsible for determining which external peripheral is the source of the interrupt.