taxi.vhd

在FPGA上实现的出租车计价器VHDL源代码

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
entity taxi is
port ( f_1,clk_50,f_in,clk:in std_logic;                                                  
       start :in std_logic;                               
       waiting:in std_logic;                                             
       cha3,cha2,cha1,cha0:out std_logic_vector(3 downto 0);
       km2, km1,km0:out std_logic_vector(3 downto 0);               
       min1,min0: out std_logic_vector(3 downto 0));       
end taxi;
architecture behav of taxi is
signal f_15,f_100m: std_logic:='0';                       
signal q_15:integer range 0 to 15;
signal temp:integer range 0 to 31;               
signal w:integer range 0 to 59;  
signal k2,k1,k0:std_logic_vector(3 downto 0):="0000";            
signal m1:std_logic_vector(3 downto 0):="0000";               
signal m0:std_logic_vector(3 downto 0):="0000";                
signal change,temp1,cha ,ch_min: integer range 0 to 10000;
signal c0,c1,c2,c3:std_logic_vector(3 downto 0):="0000";
signal a:std_logic:='0';                        
begin
p0:process(f_in)
begin
  if f_in'event and f_in='1'then
        if q_15=15 then 
           q_15<=0;
           f_15<='1';          
          else 
           q_15<=q_15+1;
           f_15<='0';
        end if;      
   end if;
end process;
p1:process(f_15)
begin
    if f_15'event and f_15='1' then
        if temp=31 then
            temp<=0;
            f_100m<='1';
        else
            temp<=temp+1;
            f_100m<='0';
        end if;
    end if;
end process;
p2:process(f_100m,f_1,start,waiting)
begin
    if f_100m'event and f_100m='1' then
    if start='0' then  
        k0<="0000";k1<="0000";k2<="0000";a<='0';
        change<=0;
    elsif start='1' and waiting ='0' then     
      if k0="1001" then k0<="0000";                    
        if k1="1001" then k1<="0000";
            if k2="1001" then k2<="0000";
            else k2<=k2+1;
            end if;
        else k1<=k1+1;
        end if;
      else k0<=k0+1;
      end if;
      if k2&k1&k0>"00100000" and k2&k1<="1010" then
        if k0="0000" or k0="0101" then
           change<=change+10;
        end if;
      elsif k2&k1&k0>"10100000" then
          if k0="0000" or k0="0101" then
            change<=change+10;         
      end if;
   end if;   
   end if;
   end if;
end process;
p3:process(f_1)
begin
  if f_1'event and f_1='1' then
    if start='0' then 
       w<=0;m1<="0000";m0<="0000";ch_min<=0;
    elsif waiting='1' then 
      if w=59 then w<=0;                             
        if m0="1001" then m0<="0000";                 
          if m1<="0101" then m1<="0000";
          else m1<=m1+1;
               ch_min<=ch_min+10;
          end if;
        else 
          m0<=m0+1;
          ch_min<=ch_min+10;          
        end if;        
      else w<=w+1;
      end if;         
  end if;
  end if;
end process;
p4:process(clk_50,clk)
begin     
 if clk_50'event and  clk_50='1' then
    if ch_min>20 then
        cha<=change+100+ch_min-30;
        else
        cha<=change+100;
    end if;
end if;
if clk'event and clk='1' then
    if start='0' then 
        temp1<=0;c0<="0000";c1<="0000";
        c2<="0000";c3<="0000";
    elsif temp1<cha then
      if c0="1001" then c0<="0000";              
         if c1="1001" then c1<="0000";
            if c2="1001" then c2<="0000";
               if c3="1001" then c3<="0000";
                 else c3<=c3+1;temp1<=temp1+1;
                 end if;
                else c2<=c2+1;temp1<=temp1+1;
                end if;
             else c1<=c1+1;temp1<=temp1+1;       
             end if;
       else 
         c0<=c0+1;
         temp1<=temp1+1;
       end if;   
    end if;
    cha3<=c3;
    cha2<=c2;
    cha1<=c1;
    cha0<=c0;
    km2<=k2;
    km1<=k1;
    km0<=k0;
    min1<=m1;
    min0<=m0;
    end if;
end process;
end behav;