clock_6.vhd

FPGA和VHDL的全过程和源码

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity clock_6 is
port(clk:in std_logic; --时钟输入20MHz
     clr:in std_logic; --清零端
      en:in std_logic; --暂停信号
    mode:in std_logic; --控制信号，用于选择模式
     inc:in std_logic; --置数信号
    seg7:out std_logic_vector(6 downto 0); --7段显示控制信号(abcdefg)
    scan:out std_logic_vector(5 downto 0)); --数码管地址选择信号
end clock_6;
architecture one of clock_6 is
signal state:std_logic_vector(1 downto 0); --定义4种状态
signal qhh,qhl,qmh,qml,qsh,qsl:std_logic_vector(3 downto 0); --小时、分、秒的高位和低位
signal data:std_logic_vector(3 downto 0);
signal cnt:integer range 0 to 5; --扫描数码管的计数器
signal clk1khz,clk1hz,clk2hz:std_logic; --1KHz、1Hz、2Hz的分频信号
signal blink:std_logic_vector(2 downto 0); --闪烁信号
signal inc_reg:std_logic;
signal sec,min:integer range 0 to 59;
signal hour:integer range 0 to 23;
begin
--1KHz的分频，用于扫描数码管地址
process(clk)
variable count:integer range 0 to 9999;
begin
if clk'event and clk='1' then
	if count=9999 then clk1khz<=not clk1khz;count:=0;
	else count:=count+1;
	end if;
end if;
end process;
--1Hz的分频，用于计时
process(clk1khz)
variable count:integer range 0 to 499;
begin
if clk1khz'event and clk1khz='1' then
	if count=499 then clk1hz<=not clk1hz;count:=0;
	else count:=count+1;
	end if;
end if;
end process;
--2Hz的分频，用于数码管闪烁
process(clk1khz)
variable count:integer range 0 to 249;
begin
if clk1khz'event and clk1khz='1' then
	if count=249 then clk2hz<=not clk2hz;count:=0;
	else count:=count+1;
	end if;
end if;
end process;
--模式转换
process(mode,clr)
begin
if clr='0' then
	state<="00";
elsif mode'event and mode='0' then
	state<=state+1;
end if;
end process;
--状态控制
process(clk1hz,state,en,clr,hour,sec,min)
begin
if en='0' then
	hour<=hour;
	min<=min;
	sec<=sec;
elsif clr='0' then
	hour<=0;
	min<=0;
	sec<=0;
elsif clk1hz'event and clk1hz='1' then
	case state is
	when "00"=>	if sec=59 then sec<=0; --模式0，正常计时
					if min=59 then min<=0;
						if hour=23 then hour<=0;
						else hour<=hour+1;end if;
					else min<=min+1;end if;
				else sec<=sec+1;
				end if;
	when "01"=>	if inc='0' then --模式1，设定小时时间
					if inc_reg='0' then inc_reg<='1';
						if hour=23 then hour<=0;
						else hour<=hour+1;end if;
					end if;
				else inc_reg<='0';
				end if;
	when "10"=>	if inc='0' then --模式2，设定分钟时间
					if inc_reg='0' then inc_reg<='1';
						if min=59 then min<=0;
						else min<=min+1;end if;
					end if;
				else inc_reg<='0';
				end if;
	when "11"=>	if inc='0' then --模式3，设定秒钟时间
					if inc_reg='0' then inc_reg<='1';
						if sec=59 then sec<=0;
						else sec<=sec+1;end if;
					end if;
				else inc_reg<='0';
				end if;
	end case;
end if;
end process;
--当进行时间设定时，令数码管闪烁
process(state,clk2hz)
begin
	case state is
		when "00"=>blink<="000";
		when "01"=>blink<=(2=>clk2hz,others=>'0');
		when "10"=>blink<=(1=>clk2hz,others=>'0');
		when "11"=>blink<=(0=>clk2hz,others=>'0');
	end case;
end process;
--秒计数的十进制转BCD码
process(sec)
begin
	case sec is
		when 0|10|20|30|40|50=>qsl<="0000";
		when 1|11|21|31|41|51=>qsl<="0001";
		when 2|12|22|32|42|52=>qsl<="0010";
		when 3|13|23|33|43|53=>qsl<="0011";
		when 4|14|24|34|44|54=>qsl<="0100";
		when 5|15|25|35|45|55=>qsl<="0101";
		when 6|16|26|36|46|56=>qsl<="0110";
		when 7|17|27|37|47|57=>qsl<="0111";
		when 8|18|28|38|48|58=>qsl<="1000";
		when 9|19|29|39|49|59=>qsl<="1001";
		when others=>null;
	end case;
	case sec is
		when 0|1|2|3|4|5|6|7|8|9=>qsh<="0000";
		when 10|11|12|13|14|15|16|17|18|19=>qsh<="0001";
		when 20|21|22|23|24|25|26|27|28|29=>qsh<="0010";
		when 30|31|32|33|34|35|36|37|38|39=>qsh<="0011";
		when 40|41|42|43|44|45|46|47|48|49=>qsh<="0100";
		when 50|51|52|53|54|55|56|57|58|59=>qsh<="0101";
		when others=>null;
	end case;
end process;
--分计数的十进制转BCD码
process(min)
begin
	case min is
		when 0|10|20|30|40|50=>qml<="0000";
		when 1|11|21|31|41|51=>qml<="0001";
		when 2|12|22|32|42|52=>qml<="0010";
		when 3|13|23|33|43|53=>qml<="0011";
		when 4|14|24|34|44|54=>qml<="0100";
		when 5|15|25|35|45|55=>qml<="0101";
		when 6|16|26|36|46|56=>qml<="0110";
		when 7|17|27|37|47|57=>qml<="0111";
		when 8|18|28|38|48|58=>qml<="1000";
		when 9|19|29|39|49|59=>qml<="1001";
		when others=>null;
	end case;
	case min is
		when 0|1|2|3|4|5|6|7|8|9=>qmh<="0000";
		when 10|11|12|13|14|15|16|17|18|19=>qmh<="0001";
		when 20|21|22|23|24|25|26|27|28|29=>qmh<="0010";
		when 30|31|32|33|34|35|36|37|38|39=>qmh<="0011";
		when 40|41|42|43|44|45|46|47|48|49=>qmh<="0100";
		when 50|51|52|53|54|55|56|57|58|59=>qmh<="0101";
		when others=>null;
	end case;
end process;
--小时计数的十进制转BCD码
process(hour)
begin
	case hour is
		when 0|10|20=>qhl<="0000";
		when 1|11|21=>qhl<="0001";
		when 2|12|22=>qhl<="0010";
		when 3|13|23=>qhl<="0011";
		when 4|14=>qhl<="0100";
		when 5|15=>qhl<="0101";
		when 6|16=>qhl<="0110";
		when 7|17=>qhl<="0111";
		when 8|18=>qhl<="1000";
		when 9|19=>qhl<="1001";
		when others=>null;
	end case;
	case hour is
		when 0|1|2|3|4|5|6|7|8|9=>qhh<="0000";
		when 10|11|12|13|14|15|16|17|18|19=>qhh<="0001";
		when 20|21|22|23=>qhh<="0010";
		when others=>null;
	end case;
end process;
process(clk1khz)
begin
if clk1khz'event and clk1khz='1' then
	if cnt=5 then cnt<=0;
	else cnt<=cnt+1;
	end if;
end if;
end process;
--数码管动态扫描
process(cnt,qhh,qhl,qmh,qml,qsh,qsl,blink)
begin
case cnt is
	when 0=>data<=qsl or (blink(0)&blink(0)&blink(0)&blink(0));scan<="000001";
	when 1=>data<=qsh or (blink(0)&blink(0)&blink(0)&blink(0));scan<="000010";
	when 2=>data<=qml or (blink(1)&blink(1)&blink(1)&blink(1));scan<="000100";
	when 3=>data<=qmh or (blink(1)&blink(1)&blink(1)&blink(1));scan<="001000";
	when 4=>data<=qhl or (blink(2)&blink(2)&blink(2)&blink(2));scan<="010000";
	when 5=>data<=qhh or (blink(2)&blink(2)&blink(2)&blink(2));scan<="100000";
	when others=>null;
end case;
end process;
--7段译码
process(data)
begin
case data is
	when "0000"=>seg7<="1000000";
	when "0001"=>seg7<="1111001";
	when "0010"=>seg7<="0100100";
	when "0011"=>seg7<="0110000";
	when "0100"=>seg7<="0011001";
	when "0101"=>seg7<="0010010";
	when "0110"=>seg7<="0000010";
	when "0111"=>seg7<="1111000";
	when "1000"=>seg7<="0000000";
	when "1001"=>seg7<="0010000";
	when others=>seg7<="1111111";
end case;
end process;
end one;