EEPW论坛

实验一、流水灯实验！
初学者必学的实验！在此次中为大家书写实验代码，已经经过测试的，可以移植 FPGA，稍微的差别就是建立工程中，得根据开发板的具体管脚而相应的配置！！

--本实验为LED流水灯实验。

LIBRARY IEEE;                                                 
USE IEEE.STD_LOGIC_1164.ALL;                    
USE IEEE.std_logic_unsigned.ALL;                  
ENTITY LampsSequencer is                                       
     PORT(
          clk:in STD_LOGIC;                                  
          led1:out STD_LOGIC_VECTOR(7 DOWNTO 0));    
END LampsSequencer;
                                            
ARCHITECTURE light OF LampsSequencer IS           
SIGNAL clk1,CLK2:std_logic;                                      
BEGIN                                                                 
P1:PROCESS (clk)                                             
VARIABLE count:INTEGER RANGE  0 TO 999999;
BEGIN                                                               
    IF clk'EVENT AND clk='1' THEN                            --当时钟脉冲上升沿到来时执行下面语句
       IF count<=499999 THEN                          
          clk1<='0';                                          --当count<=499999时divls=0并且count加1
          count:=count+1;                         
        ELSIF count>=499999 AND count<=999999 THEN            --当ount>=499999 并且 count<=999998时
               clk1<='1';                                            --                            
               count:=count+1;                                --clk1=1并且count加1
        ELSE count:=0;                                        --当count>=499999时清零count1
        END IF;                                                     
     END IF;                                         
END PROCESS ;       
P3:PROCESS(CLK1)  
begin
   IF clk1'event AND clk1='1'THEN 
 clk2<=not clk2;
 END IF;
END PROCESS P3;    
---------------------------------------------------------
P2:PROCESS(clk2)                                             
variable count1:INTEGER RANGE 0 TO 16;                         --定义的整型变量用做计数器
BEGIN                                                                --                                                
IF clk2'event AND clk2='1'THEN                                 --当时钟脉冲上升沿到来时执行下面语句
   if count1<=16 then                                          --当COUNT1<=9时执行下面语句
      if count1=15 then                                        --当COUNT1=8时，COUNT1清零
         count1:=0;                                                 --
      end if;                                                            --
      CASE count1 IS                                             --CASE语句给输出LED1赋值
      WHEN 0=>led1<="11111110";                        --依次点亮发光二极管
      WHEN 1=>led1<="11111100";                        --
      WHEN 2=>led1<="11111000";                        --
      WHEN 3=>led1<="11110000";                        --
      WHEN 4=>led1<="11100000";                        --
      WHEN 5=>led1<="11000000";                        --
      WHEN 6=>led1<="10000000";                        --
      WHEN 7=>led1<="00000000";
      WHEN 8=>led1<= "01111111";                        --依次点亮发光二极管
      WHEN 9=>led1<= "00111111";                        --
      WHEN 10=>led1<="00011111";                        --
      WHEN 11=>led1<="00001111";                        --
      WHEN 12=>led1<="00000111";                        --
      WHEN 13=>led1<="00000011";                        --
      WHEN 14=>led1<="00000001";                        --
      WHEN 15=>led1<="00000000";                        --                       --
      WHEN OTHERS=>led1<="11111111";             
      END CASE;                                                    
      count1:=count1+1;                                  
    end if;                                                                    
end if;                                                                       
end process;                             
END light;