main:
      # Set PWM duty to ~50% and enable
      LUI   $t0, 0xFFFF
      ORI   $t0, $t0, 0x0000      # $t0 = FAN_DUTY addr
      ORI   $t1, $zero, 128       # duty = 128
      SW    $t1, 0($t0)

      LUI   $t2, 0xFFFF
      ORI   $t2, $t2, 0x0008      # $t2 = FAN_CTRL addr
      ORI   $t3, $zero, 1         # enable = 1
      SW    $t3, 0($t2)

loop:   LUI   $t4, 0xFFFF
      ORI   $t4, $t4, 0x0004      # tach addr
      LW    $t5, 0($t4)           # read tach_count (optional)
      J     loop
      NOP