# VHDL1061: Clock names should be preserved across the design ## Summary ```{raw} html

Reliability	Security	Maintainability	Code attribute	Effort to fix	Tags

MEDIUM	-	HIGH	Intentionality \| Clear	30min	synthesis, cnes-custom, bug-finder, cnes-custom-cne-02300, clock, linty-ultra

``` ## Description ```{raw} html

To better understand clock usage, clock names should be preserved across the design.

Noncompliant code example

With prefixToIgnore and suffixToIgnore parameters not set:

entity top is
  port(
    clk : in std_logic;
    ...
  )
end;

entity fly is
  port(
    i_myclock : in std_logic; -- Noncompliant: 'i_myclock' should be 'clk' instead
    ...
  )
end;

architecture rtl of top is
begin
  fly_i1 : entity work.fly(rtl)
  port map(
    i_myclock => clk, -- Noncompliant: 'i_myclock' should be 'clk' instead
    ...
  );
end;

With prefixToIgnore set to (i|o|io)_:

entity top is
  port(
    clk : in std_logic;
    ...
  )
end;

entity fly is
  port(
    i_myclock : in std_logic; -- Noncompliant: 'i_myclock' should be either 'clk' or 'i_clk'
    ...
  )
end;

architecture rtl of top is
begin
  fly_i1 : entity work.fly(rtl)
  port map(
    i_myclock => clk, -- Noncompliant: 'i_myclock' should be either 'clk' or 'i_clk'
    ...
  );
end;

Compliant solution

With prefixToIgnore and suffixToIgnore parameters not set:

entity top is
  port(
    clk : in std_logic;
    ...
  )
end;

entity fly is
  port(
    clk : in std_logic; -- Compliant
    ...
  )
end;

architecture rtl of top is
begin
  fly_i1 : entity work.fly(rtl)
  port map(
    clk => clk, -- Compliant
    ...
  );
end;

With prefixToIgnore set to (i|o|io)_:

entity top is
  port(
    clk : in std_logic;
    ...
  )
end;

entity fly is
  port(
    i_clk : in std_logic; -- Compliant
    ...
  )
end;

architecture rtl of top is
begin
  fly_i1 : entity work.fly(rtl)
  port map(
    i_clk => clk, -- Compliant
    ...
  );
end;

``` ## Parameters No parameters. ```{raw} html ```