jianzhong.vhd

最基本的vhdl程序

 entity jianzhong is
  port(clk,clr,s0,s1,s2,s3,s4,s5,s6:in bit;
       ds:buffer bit_vector (3 downto 0);
       y:buffer bit_vector (7 downto 0));
end jianzhong;
architecture zhong of jianzhong is
     signal a,c:integer range 0 to 9;
     signal b,d:integer range 0 to 5;
     signal f:bit_vector (2 downto 0);
 begin   
   x1:process(s0,s1,s2,s3,s4,s5,s6,clr)
                variable i:integer range 0 to 1000;
         begin 
         --   if clk'event and clk='1' and clk'last_value='0' then
          --   if i<1000 then i:=i+1;
          --   else i:=0;
                 
                        if s0='0' then f<="001";              
                     elsif s1='0' then f<="010";
                     elsif s2='0' then f<="011";
                     elsif s3='0' then f<="100";  
                     elsif s4='0' then f<="101"; 
                     elsif s5='0' then f<="110";
                     elsif s6='0' then f<="111";
                     elsif clr='0' then f<="000";
                     end if;
             -- end if;
        -- end if;
       end process;
   x2:process(clk,clr)
         variable i:integer range 0 to 1000;
       begin 
         if clr='0' then a<=0;b<=0;c<=0;d<=0;
		 elsif clk'event  and  clk'last_value='0' and clk='1' then
           if i<1000 then i:=i+1;
             else i:=0;
                 if a<9 then a<=a+1;
			     else a<=0;
                      if b<5 then b<=b+1;
			          else b<=0;
                            if c<9 then c<=c+1;
			                else c<=0;
                                if d<5 then d<=d+1;
			                    else d<=0;
                                end if;
                             end if;
                       end if;
                 end if;
                end if;
              end if;
       
       end process;
        

	x3:process(clk,f)
       variable t: integer range 0 to 3;
	   begin 
	        if f="001" then y<="11111101" ;ds<="0000";
	     elsif f="010" then y<="01100001";ds<="0000";
	     elsif f="011" then y<="11011011";ds<="0000";

	     elsif f="100" then y<="11110011";ds<="0000";
         elsif f="101" then y<="01100111";ds<="0000";
         elsif f="110" then y<="10110111";ds<="0000";
         elsif f="111" then y<="10111111";ds<="0000";
         elsif f="000" then
		   if clk'event  and  clk'last_value='0' and clk='1' then
		        t:=t+1;
		     if t=1  then   
			    if    a=0  then y<="11111101" ;ds<="1110";
		        elsif a=1  then y<="01100001" ;ds<="1110";
                elsif a=2  then y<="11011011" ;ds<="1110";
                elsif a=3  then y<="11110011" ;ds<="1110";
                elsif a=4  then y<="01100111" ;ds<="1110";
                elsif a=5  then y<="10110111" ;ds<="1110";
                elsif a=6  then y<="10111111" ;ds<="1110";
                elsif a=7  then y<="11100001" ;ds<="1110";
                elsif a=8  then y<="11111111" ;ds<="1110";
                elsif a=9  then y<="11110111" ;ds<="1110";
                end if;
              elsif t=2  then      

                   if b=1  then y<="01100001" ;ds<="1101";
                elsif b=2  then y<="11011011" ;ds<="1101";
                elsif b=3  then y<="11110011" ;ds<="1101";
                elsif b=4  then y<="01100111" ;ds<="1101";
                elsif b=5  then y<="10110111" ;ds<="1101";
				elsif b=0  then y<="11111101" ;ds<="1101";
				end if;
			elsif t=3 then
				
				   if c=1  then y<="01100001" ;ds<="1011";
                elsif c=2  then y<="11011011" ;ds<="1011";
                elsif c=3  then y<="11110011" ;ds<="1011";
                elsif c=4  then y<="01100111" ;ds<="1011";
                elsif c=5  then y<="10110111" ;ds<="1011";
                elsif c=6  then y<="10111111" ;ds<="1011";
                elsif c=7  then y<="11100001" ;ds<="1011";
                elsif c=8  then y<="11111111" ;ds<="1011";
                elsif c=9  then y<="11110111" ;ds<="1011";
				elsif c=0  then y<="11111101" ;ds<="1011";
                end if;
			else
				if    d=1  then y<="01100001" ;ds<="0111";
                elsif d=2  then y<="11011011" ;ds<="0111";
                elsif d=3  then y<="11110011" ;ds<="0111";
                elsif d=4  then y<="01100111" ;ds<="0111";
                elsif d=5  then y<="10110111" ;ds<="0111";
				elsif d=0  then y<="11111101" ;ds<="0111";
				end if;
			end if;
		 end if;  
		end if;   
   end process;
end zhong;