def METHOD_NAME(self, port_num):
    # Check for invalid port_num
    if port_num < self.port_start or port_num > self.port_end:
        return False
    if port_num > 16:
        cpld_addr = 33
    else:
        cpld_addr = 32
    file_path = "/sys/bus/i2c/devices/1-00" + \
        str(cpld_addr) + "/port" + str(port_num) + "/port" + str(port_num) + "_lpmode"
    try:
        reg_file = open(file_path)
    except IOError as e:
        print("Error: unable to open file: %s" % str(e))
    content = reg_file.readline().rstrip()
    # content is a string containing the hex representation of the register
    reg_value = int(content, 16)
    # LPMode is active high
    if reg_value == 0:
        return False
    return True