八位数码管的动态显示VHDL程序

use ieee.std_logic_1164.all;

use ieee.std_logic_arith.all;

use ieee.std_logic_unsigned.all;

--------------------------------------------------------------------

entity seg_display is

port( clk : in std_logic; --定义动态扫描时钟信号reset : in std_logic; --定义复位信号

ledag : out std_logic_vector(6 downto 0); --定义数码管的七段输出信号

del : out std_logic_vector(2 downto 0) --定义八位数码管位置显示信号);

end seg_display;

--------------------------------------------------------------------

architecture whphtao of seg_display is

signal clk1Khz : std_logic; --数码管扫描时钟

signal clk1hz : std_logic; --计数时钟

signal cq : std_logic_vector(3 downto 0);--计数值

begin

PROCESS(clk) --产生1hz信号

variable cnt : INTEGER RANGE 0 TO 49999999;

BEGIN

IF clk='1' AND clk'event THEN

IF cnt=49999999 THEN cnt:=0;

ELSE

IF cnt<25000000 THEN clk1hz<='1';

ELSE clk1hz<='0';

END IF;

cnt:=cnt+1;

END IF;

END IF;

end process;

PROCESS(clk) --产生1Khz信号

variable cnt1 : INTEGER RANGE 0 TO 49999;

BEGIN

IF clk='1' AND clk'event THEN

IF cnt1=49999 THEN cnt1:=0;

ELSE

IF cnt1<25000 THEN clk1khz<='1';

ELSE clk1khz<='0';

END IF;

cnt1:=cnt1+1;

END IF;

end process;

process(clk1hz,reset)

variable cqi : std_logic_vector(3 downto 0);

begin

if reset='0' then cqi:=(others =>'0');-- 计数器异步复位

elsif clk1hz'event and clk1hz='1' then--检测时钟上升沿

if cqi<15 then cqi:=cqi+1;

else cqi:=(others =>'0');

end if;

--end if;

end if;

cq<=cqi;--计数值向端口输出

end process;

process(clk1KHZ) --数码管动态扫描

variable dount :std_logic_vector(2 downto 0);

begin

if clk1kHZ'event and clk1kHZ='1' then--检测时钟上升沿dount:=dount+1;--计数器dount累加

end if;

del<=dount;

end process;

process(cq)--数码管显示

begin

case cq is

when "0000" => ledag <="0111111";

when "0001" => ledag <="0000110";

when "0010" => ledag <="1011011";

when "0011" => ledag <="1001111";

when "0100" => ledag <="1100110";

when "0101" => ledag <="1101101";

when "0110" => ledag <="1111101";

when "0111" => ledag <="0000111";

when "1000" => ledag <="1111111";

when "1001" => ledag <="1101111";

when "1010" => ledag <="1110111";

when "1011" => ledag <="1111100";

when "1100" => ledag <="0111001";

when "1101" => ledag <="1011110";

when "1110" => ledag <="1111001";

when "1111" => ledag <="1110001";

when others => null;

end case;

end process;

end whphtao;