c24.vhd

用VKDL语言编写的PWM控制程序很有用本例只做了5路PWM

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
entity c24 is
    Port ( clk : in std_logic;
         dout : out std_logic_vector(7 downto 0));
end c24;
architecture Behavioral of c24 is
signal count : std_logic_vector(7 downto 0);
begin
	process(clk)
	begin
	   if rising_edge(clk) then	   
		   if count(3 downto 0)="1001" then
			 count(3 downto 0)<="0000";
			count(5 downto 4)<=count(5 downto 4) +1;
         else
			count(3 downto 0)<=count(3 downto 0)+1;
         end if;
		 if count="00100011" then
		   count<="00000000";
         end if;
      end if;
    dout <= count;
   end process;
end Behavioral;