计数器锁存器、可逆计数器、任意进制计数器、分频器源程序代码

锁存器、可逆计数器、任意进制计数器、分频器源程序代码. txt你站在那不要动等我飞奔过去 雨停了 天晴了 女人你慢慢扫屋我为你去扫天下了

你是我的听说现在结婚很便宜 民政局9块钱搞定我请你吧你个笨蛋啊遇到这种事要站在我后面 跟我走总有一天你的名字会出现在我家的户口本上。 3.6.3锁存器

LIBRARY ieee;

USE ieee. std_l ogic_1164.ALL;

ENTIT Y keep IS

PORT (clk,cr,cd:IN std_l ogic;d:IN std_l ogic_vector(3 DOWNTO 0) ;q:OUT std_l ogic_vecto r(3 DOWNT O 0) ) ;

END;

ARCHI TECTURE w1 OF keep IS

BEGIN

PROCE SS(clk,cr)

BEGIN

IF cr=' 1'THEN q<=(OTHER S=>'0' ) ;

ELSIF rising_edge(clk) THEN

IF cd=' 1' THEN q<=d;

END IF;

END IF;

END PROCE SS;

END;

3.6.6可逆计数器

LIBRARY ieee;

USE ieee. std_l ogic_1164.ALL;

USE ieee. std_l ogic_unsigned.ALL;

ENTIT Y cross IS

PORT (clk,cr, s:IN std_l ogic;q:OUT std_l ogic_vecto r(3 DOWNT O 0) ;co,bo:OUT std_l ogic) ;

END;

ARCHI TETURE w2 OF cross IS

SIGNA L po:std_l ogic_vector(3 DOWNTO 0) ;

BEGINp1:PROCE SS(clk,cr)

BEGIN

IF cr=' 1' THEN po<="0000";

ELSIF clk 'EVENT AND clk='0' THEN

IF s='0' THEN

IF po=9 THEN po<="0000";

ELSE po<=po+1 ;

END IF;

ELSE IF po=0 THEN po<="1001";

ELSE po<=po-1 ;

END IF;

END IF;

END IF;

END PROCE SS;p2:PROCE SS(s)

BEGIN

IF s='0' THEN co<= po(3) AND po(0) ;

ELSE co<='0' ;bo<=NOT po(3) AND NOT po(2) AND NOT po(1)

AND NOT po(0) ;

END IF;q<=po;

END PROCE SS;

END;

3.6.7任意进制计数器

LIBRARY ieee;

USE ieee. std_l ogic_1164.ALL;

USE ieee. std_l ogic_unsigned.ALL;

ENTIT Y count 60 IS

PORT (clk,cr: IN std_l ogic;qh,pl:BUFFE R std_l ogic_vecto r(3 DOWNT O 0) ;co:OUT std_l ogic) ;

END;

ARCHI TECTURE w1 OF count 60 IS

BEGIN

PROCE SS(clk,cr)

BEGIN

IF cr=' 1' THEN qh<="0000";pl<="0000";

ELSIF clk 'EVENT AND clk='0' THEN

IF qh=5 AND pl=8 THEN co<=' 1' ;

ELSE co<='0' ;

END IF;

IF pl=9 THEN pl<="0000";

IF qh=5 THEN qh<="0000";

ELSE qh<=qh+1 ;

END IF;

ELSE pl<=pl+1 ;

END IF;

END IF;

END PROCE SS;

END;

3.6.8数控分频器

LIBRARY ieee

USE ieee. std_l ogic_1164.ALL;

USE ieee. std_l ogic_unsigned.ALL;

ENTIT Y count_n IS

PORT (clk:IN std_l ogic;d:IN std_l ogic_vector(7 DOWNTO 0) ;co:OUT std_l ogic) ;

END;

ARCHI TECTURE w1 OF count_n IS

BEGIN

PROCE SS(clk)

VARIA BLE q:std_l ogic_vecto r(7 DOWNTO 0) ;BEGIN

IF clk 'EVENT AND clk =' 1' THEN

IF q=d-1 THEN q:=(OTHER S=>'0' ) ;co<=' 1' ;ELSE q:=q+1 ;co<='0' ;

END IF;

END IF;

END PROCE SS;

END;