-- GENERADOR DE FRECUENCIAS.
-- Autor: Iván López Espejo.
LIBRARY ieee;
USE ieee.std_logic_1164.ALL;

ENTITY GenFrec IS
    PORT
    (
        Frecuencia    : IN      STD_LOGIC_VECTOR(3 DOWNTO 0);
        CLK           : IN      STD_LOGIC;
        CLKOut        : OUT     STD_LOGIC
    );
END GenFrec;

ARCHITECTURE arq OF GenFrec IS

    SIGNAL   Modula   : INTEGER RANGE 0 TO 12588 := 0;
    SIGNAL   Contador : INTEGER RANGE 0 TO 12588 := 0;
    SIGNAL   Valor    : STD_LOGIC;

BEGIN

        WITH Frecuencia SELECT
            Modula <= 12588 WHEN "1111",
                      6294  WHEN "1110",
                      4196  WHEN "1101",
                      3147  WHEN "1100",
                      2518  WHEN "1011",
                      2098  WHEN "1010",
                      1799  WHEN "1001",
                      1574  WHEN "1000",
                      1399  WHEN "0111",
                      1259  WHEN "0110",
                      1145  WHEN "0101",
                      1049  WHEN "0100",
                       969  WHEN "0011",
                       900  WHEN "0010",
                       840  WHEN "0001",
                       787  WHEN "0000",
                         0  WHEN OTHERS;
   
    PROCESS (CLK,Modula,Valor)
       
    BEGIN
        IF CLK'event AND CLK = '1' THEN
            IF Contador < Modula THEN
                Contador <= Contador + 1;
            ELSE
                Contador <= 0;
                Valor <= not Valor;
                CLKOut <= Valor;
            END IF;
        END IF;
    END PROCESS;

END arq;