measure.vhd

一些很好的FPGA设计实例

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

--测量部分；
entity measure is
    Port (clk   : in std_logic;	  --1Hz扫描频率；
	       clk10 : in std_logic;    --1kHz扫描频率；
s df    
			 start : in std_logic;	  --使能信号；
			 dina  : in std_logic;	  --停车信号；
			 dinb  : in std_logic;	  --路程脉冲信号；
			 distance : out std_logic_vector(15 downto 0); --总行车路程；
			 stime : out std_logic_vector(15 downto 0);   --总停车时间；
			 rtime : out std_logic_vector(15 downto 0);   --总行车时间；
			 amoney: out std_logic_vector(15 downto 0));	--计费；
end measure;

architecture Behavioral of measure is

signal stime_all      : std_logic_vector(15 downto 0);
signal rtime_all		 : std_logic_vector(15 downto 0);
signal distance_all   : std_logic_vector(7 downto 0);
signal money_distance : std_logic_vector(15 downto 0);
signal money_stime    : std_logic_vector(15 downto 0);
signal money_all      : std_logic_vector(15 downto 0);

begin
--------------------------------------------------------------------------------------------------------
---                      路程测量
--------------------------------------------------------------------------------------------------------
process(dinb,start,dina)
variable cnt_bdistance : integer range 0 to 3;
begin
   if start='1' then	cnt_bdistance:=0;
	   money_distance<="0000000000000000";
		distance_all<="00000000";
   elsif dinb'event and dinb='1' then	 
	   if  dina='0' then
	      if cnt_bdistance<2 then cnt_bdistance:=cnt_bdistance+1;	 --基本路程3公里；
	      else money_distance<=money_distance+15;                   --超过3公里，每公里按1.5元收费；
		   end if;

		   if distance_all(3 downto 0)="1001" then distance_all(3 downto 0)<="0000";		--总的行车路程；
		      if distance_all(7 downto 4)="1001" then distance_all(7 downto 4)<="0000";
			   else distance_all(7 downto 4)<=distance_all(7 downto 4)+1;
			   end if;
         else distance_all(3 downto 0)<=distance_all(3 downto 0)+1;
			end if;
		end if;
   end if;
end process;

distance<="11111111"&distance_all;

--------------------------------------------------------------------------------------------------------
---                      时间测量
--------------------------------------------------------------------------------------------------------

process(clk,start)
variable cnt_time1 : integer range 0 to 60;
variable cnt_time2 : integer range 0 to 60;							 --2分钟计时；
begin
   if start='1' then cnt_time1:=0;cnt_time2:=0;
	   money_stime<="0000000000000000";
		stime_all<="0000000000000000";
	elsif clk'event and clk='1' then
	   if dina='1' then
	      if cnt_time2<59 then cnt_time2:=cnt_time2+1;     --超过2分钟，每分钟按1.1元收费；
		   elsif cnt_time1<59 then cnt_time1:=cnt_time1+1;
		   else cnt_time1:=0;money_stime<=money_stime+11;
	   	end if;
      
		   if stime_all(3 downto 0)="1001" then stime_all(3 downto 0)<="0000";						 --停留的总时间（单位：秒）；
		      if stime_all(7 downto 4)="1001" then stime_all(7 downto 4)<="0000";
			   	if stime_all(11 downto 8)="1001" then stime_all(11 downto 8)<="0000";
				      if stime_all(15 downto 12)="1001" then stime_all(15 downto 12)<="0000";
				   	else stime_all(15 downto 12)<=stime_all(15 downto 12)+1;	end if;
			      else stime_all(11 downto 8)<=stime_all(11 downto 8)+1;end if;
		      else stime_all(7 downto 4)<=stime_all(7 downto 4)+1;end if;
         else stime_all(3 downto 0)<=stime_all(3 downto 0)+1;end if;
		end if;
   end if;
end process;

stime<=stime_all;

process(start,clk)
begin
   if start='1' then rtime_all<="0000000000000000";
	elsif clk'event and clk='1' then
		if rtime_all(3 downto 0)="1001" then rtime_all(3 downto 0)<="0000";						 --总行车时间（单位：秒）；
		   if rtime_all(7 downto 4)="1001" then rtime_all(7 downto 4)<="0000";
				if rtime_all(11 downto 8)="1001" then rtime_all(11 downto 8)<="0000";
				   if rtime_all(15 downto 12)="1001" then rtime_all(15 downto 12)<="0000";
					else rtime_all(15 downto 12)<=rtime_all(15 downto 12)+1;	end if;
				else rtime_all(11 downto 8)<=rtime_all(11 downto 8)+1;end if;
			else rtime_all(7 downto 4)<=rtime_all(7 downto 4)+1;end if;
      else rtime_all(3 downto 0)<=rtime_all(3 downto 0)+1;end if;
   end if;
end process;

rtime<=rtime_all;

--------------------------------------------------------------------------------------------------------
---                      价格换算（用BCD码显示价格）
--------------------------------------------------------------------------------------------------------
money_all<=100 + money_distance + money_stime;	      --100为10.0元（基本收费）；

process(start,clk10)
variable state : integer range 0 to 5;
variable mhh,mhl,mlh,mll : std_logic_vector(3 downto 0);
variable money : std_logic_vector(15 downto 0);
begin
   if start='1' then state:=0;
	   amoney<="0000000000000000";
	elsif clk10'event and clk10='1' then 
	   case state is
		when 0 =>
		         money:=money_all;
					mhh:="0000";
					mhl:="0000";
					mlh:="0000";
					mll:="0000";
					state:=1;
      when 1 =>
	            if money>999 then money:=money-1000;mhh:=mhh+1;
					else state:=2;
					end if;
					
      when 2 =>
		         if money>99 then money:=money-100;mhl:=mhl+1;
					else state:=3;
					end if;
					
      when 3 =>
					if money>9 then money:=money-10;mlh:=mlh+1;
					else state:=4;
					end if;
					
      when 4 =>
		         mll:=money(3 downto 0);
					state:=5;
      when 5 =>
					amoney<=mhh&mhl&mlh&mll;
					state:=0;
      when others =>
		         state:=0;
      end case;
   end if;
end process;
end Behavioral;