xxout.vhd

来自「步进电机8细分CPLD相序及外部DA输出 实际细分数可达64细分 使用Atm」· VHDL 代码 · 共 30 行

library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_arith.all;
use IEEE.std_logic_unsigned.all;
entity xxout is
    port (        
          clk:in std_logic;
          flag: buffer STD_LOGIC   
 );
end xxout;
architecture behave of xxout is
begin   
  -- <<enter your statements here>>    
    P1:process(clk) 
    variable first :std_logic;              
    begin            
       if clk'event and clk='1'  then           
           if (first='0')  then
                flag<='0';
                first:='1';
           else 
                flag<='1';
           end if;        
        end if;
    end process;           
end behave;