Polling vs. interrupts

• Software must repeatedly check for the brake pedal port

• Use automatic detection capability of processor

• Connect brake pedal to interrupt port or input capture port

  • register interrupt handler
    • poke (InterruptVector, brakePedalHandler)
  • interrupt handler
    • brakePressed = true
    • poke (InterruptReg, ClearInterruptFlag)

micro

controller

int

port

brake pedal pressed

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