chui.vhd

波形发生器之疏密波的产生

--捶 (等宽度等间隔的正负脉冲组输出，此脉冲比较规律)
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_ARITH.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;

entity chui is
  port(clk:in std_logic;
       outp:out integer range 0 to 1023);
end chui;

ARCHITECTURE rtl OF chui IS
signal data:integer;
signal tmp:integer range 63 downto 0;
begin
    outp<=data;
 process(clk)
 begin
    if(clk'event and clk='1') then
       
           tmp<=tmp+1;
 case tmp is
    when 00=>data<=0;
	when 01=>data<=0;
	when 02=>data<=0;
	when 03=>data<=1023;
	when 04=>data<=1023;
	when 05=>data<=1023;
	when 06=>data<=1023;
	when 07=>data<=1023;
	when 08=>data<=0;
	when 09=>data<=0;
	when 10=>data<=0;
	when 11=>data<=1023;
	when 12=>data<=1023;
	when 13=>data<=1023;
	when 14=>data<=1023;
	when 15=>data<=1023;
	when 16=>data<=0;
	when 17=>data<=0;
	when 18=>data<=0;
	when 19=>data<=1023;
	when 20=>data<=1023;
	when 21=>data<=1023;
	when 22=>data<=1023;
	when 23=>data<=1023;
	when 24=>data<=0;
	when 25=>data<=0;
	when 26=>data<=0;
	when 27=>data<=1023;
	when 28=>data<=1023;
	when 29=>data<=1023;
	when 30=>data<=1023;
	when 31=>data<=1023;
	when 32=>data<=0;
	when 33=>data<=0;
	when 34=>data<=0;
	when 35=>data<=1023;
	when 36=>data<=1023;
	when 37=>data<=1023;
	when 38=>data<=1023;
	when 39=>data<=1023;
	when 40=>data<=0;
	when 41=>data<=0;
	when 42=>data<=0;
	when 43=>data<=1023;
	when 44=>data<=1023;
	when 45=>data<=1023;
	when 46=>data<=1023;
	when 47=>data<=1023;
	when 48=>data<=0;
	when 49=>data<=0;
	when 50=>data<=0;
	when 51=>data<=1023;
	when 52=>data<=1023;
	when 53=>data<=1023;
	when 54=>data<=1023;
	when 55=>data<=1023;
	when 56=>data<=0;
	when 57=>data<=0;
	when 58=>data<=0;
	when 59=>data<=1023;
	when 60=>data<=1023;
	when 61=>data<=1023;
	when 62=>data<=1023;
	when 63=>data<=1023;
    when others=>null;
end case; 
end if;
end process;
end rtl;