jfq1.vhd

出租车计费系统的 实现

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
USE IEEE.STD_LOGIC_ARITH.ALL;
entity JFQ1 is
port (
         CLKS,CLK,COF,CON,RESET,KM,JIANCE:in std_logic;
         COUT1 :OUT STD_LOGIC;
         MONEY1,MONEY2:OUT  INTEGER RANGE 9 DOWNTO	0   );
end;
architecture behv of JFQ1 is
          
     SIGNAL CO1,CO2,CLKO: STD_LOGIC;    
BEGIN
      
     PROCESS(CLK,CLKS,JIANCE)
       BEGIN
       IF JIANCE='1' THEN CLKO<=CLK;
       ELSE CLKO<=CLKS;
       END IF;
      END PROCESS;
  PROCESS(CLKO,COF,CON,JIANCE)
      VARIABLE CNT1,CNT2:INTEGER RANGE 9 DOWNTO 0;
             BEGIN
 IF RESET='1' THEN CNT1:=0;CNT2:=0;
        ELSIF CLKO'EVENT AND CLKO='1' THEN
    IF CON='1' AND KM='1'
              THEN 
          IF JIANCE='0' THEN
            IF COF='0' THEN
             CNT1:=CNT1+4;  
                     IF  CNT1>9  THEN
                         CNT1:=CNT1-10;     
	                     CNT2:=CNT2+2;
                       ELSE CNT2:=CNT2+1;
                     END IF;
          ELSE  
             CNT1:=CNT1+1;
                 IF  CNT1>9  THEN
                     CNT1:=CNT1-10;     
	                 CNT2:=CNT2+3;
                     ELSE CNT2:=CNT2+2;
                    END IF; 
                  END IF; 
             
                ELSE 
                       CNT2:=CNT2+4;     
                        END IF;
          IF CNT2>9
                    THEN CO1<='1'; 
                     CNT2:=CNT2-10;
                    ELSE CO1<='0';
                 END IF;
   END IF;      
END IF;
MONEY1<=CNT1;
MONEY2<=CNT2;
COUT1<=CO1;
END PROCESS;
     

END ;