GameBoy\Core::runInterrupt PHP Method

    public function runInterrupt()
    {
        $bitShift = 0;
        $testbit = 1;
        $interrupts = $this->memory[0xffff] & $this->memory[0xff0f];
        while ($bitShift < 5) {
            //Check to see if an interrupt is enabled AND requested.
            if (($testbit & $interrupts) == $testbit) {
                $this->IME = false;
                //Reset the interrupt enabling.
                $this->memory[0xff0f] -= $testbit;
                //Reset the interrupt request.
                //Set the stack pointer to the current program counter value:
                $this->stackPointer = $this->unswtuw($this->stackPointer - 1);
                $this->memoryWrite($this->stackPointer, $this->programCounter >> 8);
                $this->stackPointer = $this->unswtuw($this->stackPointer - 1);
                $this->memoryWrite($this->stackPointer, $this->programCounter & 0xff);
                //Set the program counter to the interrupt's address:
                $this->programCounter = 0x40 + $bitShift * 0x8;
                //Interrupts have a certain clock cycle length:
                $this->CPUTicks += 5;
                //People say it's around 5.
                break;
                //We only want the highest priority interrupt.
            }
            $testbit = 1 << ++$bitShift;
        }
    }