void setup() {
  volatile char *outf, *dirf;
  volatile long i;
  dirf = (volatile char*)0x30;  // Set the direction register address
  *dirf = 0xff;  // Set all pins as output
  outf = (volatile char*)0x31;  // Set the output register address

  *outf = 0x00;  // Ensure all LEDs are off initially

  while (1) {
    for (int mask = 0x01; mask <= 0x80; mask <<= 1) {
      *outf |= mask;  // Turn on the current LED
      for (i = 0; i < 100000; i++);  // Delay
    }
    
    // Optionally, you can reset the sequence by turning off all LEDs and starting over
    *outf = 0x00;
    for (i = 0; i < 100000; i++);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
}