Why is this an issue?

Combinational loops lead to unpredictable design. Thus, they must be removed.

How to fix it

Code examples

Noncompliant code example

process (clk)
begin
  if rising_edge(clk) then
    a <= not(a);
  end if;
end process;

process (b)
begin
  b <= not(b) -- Noncompliant
end process;