4.3.2 Embedded Characteristics

  • Controls the Interrupt Lines (nIRQ and nFIQ) of an Arm Processor
  • 50 Individually Maskable and Vectored Interrupt Sources
    • Source 0 is reserved for the fast interrupt input (FIQ)
    • Source 1 is reserved for system peripheral interrupts
    • Source 2 to Source 49 control up to 126 embedded peripheral interrupts or external interrupts
    • Programmable edge-triggered or level-sensitive internal sources
    • Programmable rising/falling edge-triggered or high/low level-sensitive external sources
  • 8-level Priority Controller
    • Drives the normal interrupt of the processor
    • Handles priority of the interrupt sources 1 to 49
    • Higher priority interrupts can be served during service of lower priority interrupt
  • Vectoring
    • Optimizes interrupt service routine branch and execution
    • One 32-bit vector register for all interrupt sources
    • Interrupt vector register reads the corresponding current interrupt vector or the current interrupt number
  • Protect Mode
    • Easy debugging by preventing automatic operations when protect models are enabled
  • Fast Forcing
    • Permits redirecting any normal interrupt source to the fast interrupt of the processor
  • General Interrupt Mask
    • Provides processor synchronization on events without triggering an interrupt
  • Register Write Protection