Why is this an issue?

This rule checks that all output ports are connected. An unconnected port may point out a missing implementation.

How to fix it

Code examples

Noncompliant code example

With detectPartiallyUnconnected parameter set to false:

entity top is
  port (
    clk : in  std_logic;
    i1  : in  std_logic;
    i2  : in  std_logic;
    o1  : out std_logic;
    o2  : out std_logic; -- Noncompliant: Unconnected
    o3  : out std_logic_vector(1 downto 0) -- Compliant: Partially connected (bit offset #0)
  );
end entity;

architecture rtl of top is begin
  process (clk) is
  begin
    if rising_edge(clk) then
      o1 <= i1;
      o3(0) <= i2;
    end if;
  end process;
end architecture;

With detectPartiallyUnconnected parameter set to true:

entity top is
  port (
    clk : in  std_logic;
    i1  : in  std_logic;
    i2  : in  std_logic;
    o1  : out std_logic;
    o2  : out std_logic; -- Noncompliant: Unconnected
    o3  : out std_logic_vector(1 downto 0) -- Noncompliant: Partially unconnected (bit offset #1)
  );
end entity;

architecture rtl of top is begin
  process (clk) is
  begin
    if rising_edge(clk) then
      o1 <= i1;
      o3(0) <= i2;
    end if;
  end process;
end architecture;