code: def mass_erase():
      
      # Send DNLOAD with first byte=0x41
      __dev.ctrl_transfer(0x21, __DFU_DNLOAD, 0, __DFU_INTERFACE,
                          "\x41", __TIMEOUT)
  
      # Execute last command
      if get_status() != __DFU_STATE_DFU_DOWNLOAD_BUSY:
          raise Exception("DFU: erase failed")
  
      # Check command state
      if get_status() != __DFU_STATE_DFU_DOWNLOAD_IDLE:
          raise Exception("DFU: erase failed")
docs: Performs a MASS erase (i.e. erases the entire device.