VHDL实现动态数码管显示的数字钟设计

library ieee;
use  ieee.std_logic_1164.all;
use  ieee.std_logic_arith.all;
use  ieee.std_logic_unsigned.all;

entity clock is  
port (clk,clr,a,c,e,f,g: in std_logic;
            led_sel:out  std_logic_vector(2 downto 0);
            led:out      std_logic_vector(0 to 6);
            p:in         std_logic_vector(3 downto 0);
            b:in         std_logic_vector(1 downto 0);
            d:out        std_logic );
end entity clock;

architecture bhv of clock is  
      signal      m: integer range 0 to 999;
      signal      hou1,hou0,min1,min0,sec1,sec0,s2: std_logic_vector(3 downto 0);
      signal      rhou1,rhou0,rmin1,rmin0,rsec1,rsec0: std_logic_vector(3 downto 0);
      signal      s1: std_logic_vector(2 downto 0);
      signal      clk1,clk2,d1,d2:std_logic;
      signal n :  integer range 0 to 1;
        begin

p1:process(clk)        --二分频
      begin
        if (rising_edge(clk)) then
                if n=1 then n<=0;clk2<='1';
                else  n<=n+1;clk2<='0'; 
            end if;
            end if ;

      end process;
p2:process(clk)        
      begin
        if (rising_edge(clk)) then
                if m=999 then m<=0;clk1<='1';
                else m<=m+1; clk1<='0'; 
            end if;
            end if ;
      end process P2;
p3: process(clk1,clr)        ---时间设置
          begin
        if (clr='1') then sec0<="0000";sec1<="0000";
                          min0<="0000";min1<="0000";
                          hou0<="0000";hou1<="0000";      
        elsif rising_edge(clk1) then
          if a='1' then                --校时
              if     b="00" then hou1<=p;
              elsif  b="01" then hou0<=p; 
              elsif  b="10" then min1<=p; 
              elsif  b="11" then min0<=p; 
          end  if;
          end  if;
          if sec0>="1001" then 
                sec0<="0000";
              if sec1>="0101" then
                    sec1<="0000";
                  if min0>="1001" then 
                        min0<="0000";
                    if min1>="0101" then
                          min1<="0000";