xx.txt

有用的单片机程序,包括8279和E2ROM的读写

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

--将CS电平截成一个上升沿的CS
--使用条件：CLK时钟的工作频率远高于拿此当上升沿的工作时钟的频率
entity XX is
    Port (CLK,CS:IN STD_LOGIC;  
          OUTPUT: OUT STD_LOGIC );
end XX;

architecture Behavioral of XX is
SIGNAL TEMP1,TEMP2:STD_LOGIC;
begin
process(clk,CS) is
 begin
 if clk'event and clk='1' then
 temp1<=cs;
 temp2<=temp1;
 end if;
end process;
PROCESS(TEMP1,TEMP2) IS
 BEGIN
  IF TEMP1='1' AND TEMP2='0' THEN OUTPUT<='1';
  else output<='0';
  END IF;
  END PROCESS;
end Behavioral;