def METHOD_NAME(self):
    """
    clear ctl address and ctl sts CSR
    write 0x4 value ctl address csr
    write 0x1 value ctl sts csr
    poll for status
    HSSI Read Data CSR [31:16] Maximum TX frame size
    HSSI Read Data CSR [15:0] Maximum Rx frame size
    """
    self.open(self._hssi_grps[0][0])
    hssi_feature_list = hssi_feature(self.read32(0, self.hssi_csr.HSSI_FEATURE_LIST))
    if self._port >= self.hssi_csr.HSSI_PORT_COUNT:
        print("Invalid input port number")
        self.close()
        return False
    enable = self.register_field_get(hssi_feature_list.port_enable,
                                     self._port)
    if enable == 0:
        print("Input port is not enabled or active")
        self.close()
        return False
    ctl_addr = hssi_ctl_addr(0)
    ctl_addr.sal_cmd = HSSI_SAL_CMD.GET_MTU.value
    # set port number
    ctl_addr.port_address = self._port
    res, value = self.read_reg(0, ctl_addr.value)
    if not res:
        self.close()
        print("Failed to read mtu")
        return False
    mask = 0
    width = 16
    for x in range(width):
        mask |= (1 << x)
    """HSSI Read Data CSR [15:0] Maximum Rx frame size"""
    print("Port{0} Maximum RX frame size:{1}".format(self._port,
                                                     value & mask))
    """HSSI Read Data CSR [31:16] Maximum Tx frame size"""
    print("Port{0} Maximum TX frame size:{1}".format(self._port,
                                                     value >> width))
    self.close()
    return True