CLOCK

1.数字钟以1Hz的频率工作，其输入频率为1MHz。

2.数字钟显示时、分、秒信息。

这些显示信息在6个7
段数码管上完成。

3.通过按键设置时、分信息。

并且具有对数字钟的复位功能。

4.复位键将时、分、秒清零，并做好重新计数的准备。

5.按键具有预置时、分的功能。

分别对当前的时和分信息做递增设置和递减设置。

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
--实体定义部分
entity clock is
port(
clk : in std_logic;
rst : in std_logic;
inc_min : in std_logic;
sub_min : in std_logic;
inc_hour : in std_logic;
sub_hour : in std_logic;
sel : out std_logic_vector(2 downto 0);
q : out std_logic_vector(7 downto 0));
end clock;
--信号定义：
architecture Behavioral of clock is
signal sec_counter1:std_logic_vector(3 downto 0);
signal sec_counter2:std_logic_vector(3 downto 0);
signal min_counter1:std_logic_vector(3 downto 0);
signal min_counter2:std_logic_vector(3 downto 0);
signal hour_counter1:std_logic_vector(3 downto 0);
signal hour_counter2:std_logic_vector(3 downto 0);
signal divcounter : std_logic_vector(3 downto 0);
signal div_clk : std_logic;
signal scancounter : std_logic_vector(1 downto 0);
signal scan_clk : std_logic;
signal scan_out : std_logic_vector(2 downto 0);
signal secseg1,secseg2,minseg1,minseg2,hourseg1,hourseg2:std_logic_vector(7downto 0); begin
--计数时钟，对外部输入时钟分频，此处只适用于仿真，实际进行时间计数时，分频后时钟应该满足1HZ。

process(rst,clk)
begin
if(rst='0')then
divcounter<="0000";
div_clk<='0';
elsif(rising_edge(clk)) then
if(divcounter="1111") then
divcounter<="0000";
div_clk<=not div_clk;
else
divcounter<=divcounter+'1';
end if;
end if;
end process;
--仿真时数码管扫描时钟，实际中需根据具体情况进行调解时钟频率
process(rst,clk)
begin
if(rst='0')then
scancounter<="00";
scan_clk<='0';
elsif(rising_edge(clk)) then
if(scancounter="11") then
scancounter<="00";
scan_clk<=not scan_clk;
else
scancounter<=scancounter+'1';
end if;
end if;
end process;
--时钟计数部分主进程
--时钟复位
clock:process(div_clk,rst)
begin
if(rst='0')then
sec_counter1<=X"0";
sec_counter2<=X"0";
min_counter1<=X"0";
min_counter2<=X"0";
hour_counter1<=X"0";
hour_counter2<=X"0";
--手动调分，递增
elsif(rising_edge(div_clk))then
if(inc_min='0') then
if(min_counter1=X"9") then
min_counter1<=X"0";
if(min_counter2>=X"5") then
min_counter2<=X"0";
else
min_counter2<=min_counter2+1;
end if;
else
min_counter1<=min_counter1+1;
end if;
--手动调分，递减
elsif(sub_min='0') then
if(min_counter1=X"0") then
min_counter1<=X"9";
if(min_counter2=X"0")then
min_counter2<=X"5";
else
min_counter2<=min_counter2-1;
end if;
else
min_counter1<=min_counter1-1;
end if;
--手动调时，增时
elsif(inc_hour='0') then
if(hour_counter2=X"2")then
if(hour_counter1=X"3")then
hour_counter1<=X"0";
hour_counter2<=X"0";
else
hour_counter1<=hour_counter1+1;
end if;
else
if(hour_counter1=X"9") then
hour_counter1<=X"0";
hour_counter2<=hour_counter2+1;
else
hour_counter1<=hour_counter1+1;
end if;
end if;
--手动调时，减时
elsif(sub_hour='0') then
if(hour_counter1=X"0")then
if(hour_counter2=X"0")then
hour_counter1<=X"3"; hour_counter2<=X"2";
else
hour_counter2<=hour_counter2-1;
hour_counter1<=X"9";
end if;
else
hour_counter1<=hour_counter1-1;
end if;
--时分秒正常计数
else
if(sec_counter1>=X"9") then
sec_counter1<=X"0";
if(sec_counter2>=X"5") then
sec_counter2<=X"0";
if(min_counter1>=X"9") then
min_counter1<=X"0";
if(min_counter2>=X"5") then
min_counter2<=X"0";
if(hour_counter2=X"2") then
if(hour_counter1=X"3") then
hour_counter1<=X"0";
hour_counter2<=X"0";
else
hour_counter1<=hour_counter1+1;
end if;
else
if(hour_counter1=X"9") then
hour_counter1<=X"0";
hour_counter2<=hour_counter2+1;
else
hour_counter1<=hour_counter1+1;
end if;
end if;
else
min_counter2<=min_counter2+1;
end if;
else
min_counter1<=min_counter1+1;
end if;
else
sec_counter2<=sec_counter2+1;
end if;
else
sec_counter1<=sec_counter1+1;
end if;
end if;
end if;
end process clock;
--生成扫描时钟
process(rst,scan_clk)
begin
if (rst='0') then
scan_out<="000";
elsif(rising_edge(scan_clk)) then
if(scan_out="101")then
scan_out<="000";
else
scan_out<=scan_out+1;
end if;
end if;
end process;
--扫描输出进程
process(scan_out)
begin
case scan_out is
when "000" => q<=secseg1; sel<="000";
when "001" => q<=secseg2; sel<="001";
when "010" => q<=minseg1; sel<="010";
when "011" => q<=minseg2; sel<="011";
when "100" => q<=hourseg1; sel<="100";
when "101" => q<=hourseg2; sel<="101";
when others => q<="11111111";sel<="111";
end case;
end process;
--秒低位显示
second_counter1:process(sec_counter1)
begin
case sec_counter1 is
when "0000" => secseg1<="10111111";
when "0001" => secseg1<="10000110";
when "0010" => secseg1<="11011011";
when "0011" => secseg1<="11001111";
when "0100" => secseg1<="11100110";
when "0101" => secseg1<="11101101";
when "0110" => secseg1<="11111101";
when "0111" => secseg1<="10000111";
when "1000" => secseg1<="11111111";
when "1001" => secseg1<="11101111";
when others => secseg1<="11111111";
end case;
end process second_counter1;
--秒高位显示
second_counter2:process(sec_counter2)
begin
case sec_counter2 is
when "0000" => secseg2<="00111111";
when "0001" => secseg2<="00000110";
when "0010" => secseg2<="01011011";
when "0011" => secseg2<="01001111";
when "0100" => secseg2<="01100110";
when "0101" => secseg2<="01101101";
when others => secseg2<="01111111";
end case;
end process second_counter2;
--分低位显示
minute_counter1:process(min_counter1)
begin
case min_counter1 is
when "0000" => minseg1<="10111111";
when "0001" => minseg1<="10000110";
when "0010" => minseg1<="11011011";
when "0011" => minseg1<="11001111";
when "0100" => minseg1<="11100110";
when "0101" => minseg1<="11101101";
when "0110" => minseg1<="11111101";
when "0111" => minseg1<="10000111";
when "1000" => minseg1<="11111111";
when "1001" => minseg1<="11101111";
when others => minseg1<="11111111";
end case;
end process minute_counter1;
--分高位显示
minute_counter2:process(min_counter2)
begin
case min_counter2 is
when "0000" => minseg2<="00111111";
when "0001" => minseg2<="00000110";
when "0010" => minseg2<="01011011";
when "0011" => minseg2<="01001111";
when "0100" => minseg2<="01100110";
when "0101" => minseg2<="01101101";
when others => minseg2<="01111111";
end case;
end process minute_counter2;
--小时低位显示
hor_counter1:process(hour_counter1)
begin
case hour_counter1 is
when "0000" => hourseg1<="10111111";
when "0001" => hourseg1<="10000110";
when "0010" => hourseg1<="11011011";
when "0011" => hourseg1<="11001111";
when "0100" => hourseg1<="11100110";
when "0101" => hourseg1<="11101101";
when "0110" => hourseg1<="11111101";
when "0111" => hourseg1<="10000111";
when "1000" => hourseg1<="11111111";
when "1001" => hourseg1<="11101111";
when others => hourseg1<="11111111";
end case;
end process;
--小时高位显示
hor_counter2:process(hour_counter2)
begin
case hour_counter2 is
when "0000" => hourseg2<="00111111";
when "0001" => hourseg2<="00000110";
when "0010" => hourseg2<="01011011";
when others => hourseg2<="01111111";
end case;
end process;
end Behavioral;。