Subversion Repositories z80soc

-- 3.57 Mhz clock from a 50 Mhz input
-- Ronivon C. costa
-- 03/2008 
------------------------------------------------------------------
library IEEE;
use  IEEE.STD_LOGIC_1164.all;
use  IEEE.STD_LOGIC_ARITH.all;
use  IEEE.STD_LOGIC_UNSIGNED.all;
 
ENTITY Clock_357Mhz IS
	PORT (
		clock_50Mhz				: IN	STD_LOGIC;
		clock_357Mhz			: OUT	STD_LOGIC);
	END Clock_357Mhz;
 
ARCHITECTURE rtl OF Clock_357Mhz IS
 
	SIGNAL counter: STD_LOGIC_VECTOR(3 DOWNTO 0); 
	SIGNAL clock_357Mhz_int : STD_LOGIC;
 
BEGIN
 
	PROCESS (clock_50Mhz)
	BEGIN
		IF clock_50Mhz'EVENT and clock_50Mhz = '1' THEN
			IF counter < "1110" THEN
				counter <= counter + 1;
			ELSE
				counter <= "0000";
				clock_357Mhz_int <= not clock_357Mhz_int;
			END IF;
		END IF;
 
	clock_357Mhz <= clock_357Mhz_int;
 
	END PROCESS;
END rtl;