fir_vhdl/utils.vhd

-- *********************** Divers fonction utiles ***************************


LIBRARY ieee; 
USE ieee.std_logic_1164.ALL;


PACKAGE utils IS
  PROCEDURE horloge ( SIGNAL h: OUT std_logic; th, tb : time); 
  PROCEDURE horloge_retard ( SIGNAL h : OUT std_logic; periode : time ;
                             retard : time); 
END utils;
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PACKAGE BODY utils IS
  PROCEDURE horloge ( SIGNAL h : OUT std_logic; th, tb : time) IS 
  BEGIN 
    LOOP 
      h <= '0', '1' AFTER tb; 
      WAIT FOR tb + th ; 
    END LOOP; 
  END;
  
  PROCEDURE horloge_retard ( SIGNAL h : OUT std_logic; periode : time ;
                             retard : time) IS 
  BEGIN 
    h <= '0'; 
    WAIT FOR retard; 
    LOOP 
      h <= '1' , '0' AFTER periode/2 ; 
      WAIT FOR periode; 
    END LOOP; 
  END; 
END utils;