Why is this an issue?

All declared ports should be given a mode.

How to fix it

Code examples

Noncompliant code example

port (
  no, test : in std_logic;
  clk_in : in std_logic;
  clk_out : out std_logic;
  clk_div : std_logic -- Noncompliant
);

Compliant solution

port (
  no, test : in std_logic;
  clk_in : in std_logic;
  clk_out : out std_logic;
  clk_div : out std_logic
);