kevin_timer.vhd

FPGA 上的数字秒表及完整的显示功能。

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


entity kevin_timer is 
	port ( rst : in std_logic;
		   clk : in std_logic;
		   segA : out std_logic_vector (7 downto 0);
		   segB : out std_logic_vector (7 downto 0);
		   segC : out std_logic_vector (7 downto 0);
		   segD : out std_logic_vector (7 downto 0);
		   segE : out std_logic_vector (7 downto 0);
		   segF : out std_logic_vector (7 downto 0);
		   segG : out std_logic_vector (7 downto 0);
		   segH : out std_logic_vector (7 downto 0) );
end entity;


architecture timer of kevin_timer is
	
	--these signals are for number counting:
	signal cunt : integer range  0 to 99999;
	signal cunt_centisec : integer range 0 to 99;
    signal cunt_second   : integer range 0 to 59;
	signal cunt_minute   : integer range 0 to 59;
    signal cunt_hour	 : integer range 0 to 23;

	--these signals are for display:
  signal cunt_centisec_l : integer range 0 to 9;
  signal cunt_centisec_h : integer range 0 to 9;
	signal cunt_second_l   : integer range 0 to 9;
	signal cunt_second_h   : integer range 0 to 9;
	signal cunt_minute_l   : integer range 0 to 9;
	signal cunt_minute_h   : integer range 0 to 9;
	signal cunt_hour_l     : integer range 0 to 9;
  signal cunt_hour_h     : integer range 0 to 9;

begin

-- this is the calculation for timer:
	process ( rst, clk)
	begin
		if (rst='0') then 
			cunt<=0;
			cunt_centisec<=0;
			cunt_second<=0;
			cunt_minute<=0;
			cunt_hour<=0;
		elsif(clk'event and clk='1') then
			if (cunt=99999) then												
				cunt<=0;
				if (cunt_centisec=99) then
					cunt_centisec<=0;
					if (cunt_second=59) then
						cunt_second<=0;
						if (cunt_minute=59) then
							cunt_minute<=0;
							if (cunt_hour=23) then
								cunt_hour<=0;
							else cunt_hour<=cunt_hour+1;
							end if;
						else cunt_minute<=cunt_minute+1;
						end if;
					else cunt_second<=cunt_second+1;
					end if;
				else cunt_centisec<=cunt_centisec+1;
				end if;
			else cunt<=cunt+1;
			end if;
		end if;
	end process;
	

-- this is for the dis8play calculation:
	process (cunt_centisec, cunt_second, cunt_minute, cunt_hour )
	begin
		cunt_centisec_h <= cunt_centisec/10;
		cunt_centisec_l <= cunt_centisec - cunt_centisec_h*10;
		cunt_second_h   <= cunt_second/10;
		cunt_second_l   <= cunt_second - cunt_second_h*10;
		cunt_minute_h   <= cunt_minute/10;
		cunt_minute_l   <= cunt_minute - cunt_minute_h*10;
		cunt_hour_h		<= cunt_hour/10;
		cunt_hour_l		<= cunt_hour - cunt_hour_h*10;
	end process;


-- this is for display:
	process (cunt_centisec_h, cunt_centisec_l, cunt_second_h,   cunt_second_l, cunt_minute_h,	 
	 cunt_minute_l, cunt_hour_h,     cunt_hour_l)
	begin
			case cunt_centisec_l is 
				when 0	=>		segH<="11111100";
				when 1	=>		segH<="01100000";
				when 2	=>		segH<="11011010";
				when 3	=>		segH<="11110010";
				when 4	=>		segH<="01100110";
				when 5	=>		segH<="10110110";
				when 6	=>		segH<="10111110";
				when 7	=>		segH<="11100000";
				when 8	=>		segH<="11111110";
				when 9	=>		segH<="11110110";
				when others =>  segH<="00000000";
			end case;
	
	        case cunt_centisec_h is 
				when 0	=>		segG<="11111100";
				when 1	=>		segG<="01100000";
				when 2	=>		segG<="11011010";
				when 3	=>		segG<="11110010";
				when 4	=>		segG<="01100110";
				when 5	=>		segG<="10110110";
				when 6	=>		segG<="10111110";
				when 7	=>		segG<="11100000";
				when 8	=>		segG<="11111110";
				when 9	=>		segG<="11110110";
				when others =>  segG<="00000000";
			end case;
			
			case cunt_second_l is 
				when 0	=>		segF<="11111101";
				when 1	=>		segF<="01100001";
				when 2	=>		segF<="11011011";
				when 3	=>		segF<="11110011";
				when 4	=>		segF<="01100111";
				when 5	=>		segF<="10110111";
				when 6	=>		segF<="10111111";
				when 7	=>		segF<="11100001";
				when 8	=>		segF<="11111111";
				when 9	=>		segF<="11110111";
				when others =>  segF<="00000001";
			end case;
			
			case cunt_second_h is 
				when 0	=>		segE<="11111100";
				when 1	=>		segE<="01100000";
				when 2	=>		segE<="11011010";
				when 3	=>		segE<="11110010";
				when 4	=>		segE<="01100110";
				when 5	=>		segE<="10110110";
				when 6	=>		segE<="10111110";
				when 7	=>		segE<="11100000";
				when 8	=>		segE<="11111110";
				when 9	=>		segE<="11110110";
				when others =>  segE<="00000000";
			end case;
			
			
			case cunt_minute_l is 
				when 0	=>		segD<="11111101";
				when 1	=>		segD<="01100001";
				when 2	=>		segD<="11011011";
				when 3	=>		segD<="11110011";
				when 4	=>		segD<="01100111";
				when 5	=>		segD<="10110111";
				when 6	=>		segD<="10111111";
				when 7	=>		segD<="11100001";
				when 8	=>		segD<="11111111";
				when 9	=>		segD<="11110111";
				when others =>  segD<="00000001";
			end case;
				
			
			case cunt_minute_h is 
				when 0	=>		segC<="11111100";
				when 1	=>		segC<="01100000";
				when 2	=>		segC<="11011010";
				when 3	=>		segC<="11110010";
				when 4	=>		segC<="01100110";
				when 5	=>		segC<="10110110";
				when 6	=>		segC<="10111110";
				when 7	=>		segC<="11100000";
				when 8	=>		segC<="11111110";
				when 9	=>		segC<="11110110";
				when others =>  segC<="00000000";
			end case;
			
			case cunt_hour_l is
				when 0	=>		segB<="11111101";
				when 1	=>		segB<="01100001";
				when 2	=>		segB<="11011011";
				when 3	=>		segB<="11110011";
				when 4	=>		segB<="01100111";
				when 5	=>		segB<="10110111";
				when 6	=>		segB<="10111111";
				when 7	=>		segB<="11100001";
				when 8	=>		segB<="11111111";
				when 9	=>		segB<="11110111";
				when others =>  segB<="00000001";
			end case;
			
			case cunt_hour_h is 
				when 0	=>		segA<="11111100";
				when 1	=>		segA<="01100000";
				when 2	=>		segA<="11011010";
				when 3	=>		segA<="11110010";
				when 4	=>		segA<="01100110";
				when 5	=>		segA<="10110110";
				when 6	=>		segA<="10111110";
				when 7	=>		segA<="11100000";
				when 8	=>		segA<="11111110";
				when 9	=>		segA<="11110110";
				when others =>  segA<="00000000";
			end case;
	
	end process;
			
end architecture;