EmbDev.net

Forum: FPGA, VHDL & Verilog pwm modulation/demodulation


pwm modulation/demodulation
von alper y. (alperyazir)

Rate this post
• ▲ useful
▼ not useful 
hi everyone. I need help about vhdl code of spartan3e.
i wanna communicate two FBGAs. For example, i am using rotary switch to 
produce pwm(it arranges my duty cycles. and i produce my pwm from my 1st 
FBGA and use it 2nd FBGA. i tried but it didnt happened.
please help me ??

my codes is:
1
library IEEE;

2
use IEEE.STD_LOGIC_1164.ALL;

3
use IEEE.STD_LOGIC_UNSIGNED.ALL;

4
5
entity rotaryEncoder is

6
Port ( 

7
      clk  : in    STD_LOGIC; -- C9

8
      RotA : in    STD_LOGIC; -- K18 PULLUP

9
      RotB : in    STD_LOGIC; -- G18 PULLUP

10
      data : inout STD_LOGIC_VECTOR(7 DOWNTO 0); -- E12

11
      leds : inout STD_LOGIC_VECTOR(7 DOWNTO 0);

12
      sout : inout std_logic;

13
      sin  : in std_logic);

14
 end rotaryEncoder;

15
16
 architecture rotaryEncoder of rotaryEncoder is

17
 signal sta       : STD_LOGIC_VECTOR(1 downto 0);

18
 signal prr       : STD_LOGIC_vector(1 downto 0);

19
 signal rotary_in : STD_LOGIC_vector(1 downto 0);

20
 signal RotA1     : STD_LOGIC;

21
 signal RotB1     : STD_LOGIC;

22
 signal s1        :std_logic;

23
 signal s2        :std_logic;

24
 signal s3        :std_logic;

25
 signal s4        :std_logic;

26
 signal s5        :std_logic_vector(3 downto 0);

27
 signal s6        :std_logic;

28
 signal s7        :std_logic_vector(1 downto 0);

29
 signal cmp        :std_logic_vector(3 downto 0);

30
 signal xcount3   : std_logic_vector(7 downto 0);

31
 signal xcount1   : std_logic_vector(8 downto 0);

32
 signal reg       :std_logic_vector(7 downto 0);

33
 

34
 begin

35
 rotary_filter: 

36
 process(clk)    

37
  begin                   

38
    if clk'event and clk='1' then  

39
    rotary_in <= RotA & RotB;      

40
        case rotary_in is  

41
42
          when "00" => RotA1 <= '0';     RotB1 <= RotB1;   

43
          when "01" => RotA1 <= RotA1;   RotB1 <= '0';      

44
          when "10" => RotA1 <= RotA1;   RotB1 <= '1';     

45
          when "11" => RotA1 <= '1';     RotB1 <= RotB1;   

46
          when others => RotA1 <= RotA1; RotB1 <= RotB1;                

47
        end case;                    

48
    end if;                        

49
 end process rotary_filter;     

50
51
 direction:

52
  process(clk) is begin

53
      if(rising_edge(clk)) then

54
        case sta & RotA1 & RotB1 is

55
    when "0001" => prr <= "01"; sta <="01"; -- 01 turn right

56
          when "0010" => prr <= "00"; sta <="10"; -- 00 turn left

57
    when "0111" => prr <= "01"; sta <="11"; -- 10 null

58
    when "0100" => prr <= "00"; sta <="00";

59
    when "1000" => prr <= "10"; sta <="00";

60
    when "1011" => prr <= "10"; sta <="11";

61
    when "1110" => prr <= "10"; sta <="10";

62
    when "1101" => prr <= "10"; sta <="01";

63
    when others => null;

64
        end case;

65
          if(prr="00") then

66
            data<=data+1; prr<="10";

67
          elsif(prr="01") then

68
            data<=data-1; prr<="10";

69
          else

70
            null;

71
          end if;

72
       end if;

73
   end process;

74
75
  TRNS:process(clk) is begin 

76
    if clk'event and clk='1' then

77
      

78
        if(xcount1<="000000000") then

79
        sout<='1';

80
        elsif(xcount1="000000001") then

81
        sout<='1';

82
        elsif(xcount1="000000010") then

83
        sout<='0';

84
        elsif(xcount1="000000011") then

85
        sout<='0';

86
87
        elsif((xcount1<=data)and(xcount1>"000000011")) then

88
            sout<='1';

89
        elsif(xcount1<="100000011") then

90
          sout<='0';

91
        elsif(xcount1="100000011") then

92
        xcount1<="000000000";  

93
        end if;

94
    xcount1<= xcount1 + 1;

95
    end if;

96
 end process;

97
 

98
 RCV:process(clk,sin,s1,s2,s3,s4,s5,s6,s7)is begin

99
       if(rising_edge(clk)) then

100
        

101
          s1<=sin;

102
         s2<=s1;

103
         s3<=s2;

104
         s4<=s3;

105
          s5<=s1&s2&s3&s4;

106
          s7<=s6&sin;

107
         if(s5="0011") then

108
        s6<='1';

109
        end if;

110
        if(s7="11") then

111
        

112
            leds<=leds;

113
            reg<=xcount3;

114
        else

115
            leds<=reg-3;

116
        end if;

117
        xcount3<= xcount3 + 1;

118
        

119
        if(xcount3="11111111") then

120
          xcount3<="00000000";

121
        end if;

122
         if(reg="11111111") then

123
         reg<="00000000";

124
         end if;

125
      end if;

126
    end process;

127
 end rotaryEncoder;


  


  




  

    Report post Edit Move Thread sperren Anmeldepflicht aktivieren Anpinnen Delete topic Thread mit anderem zusammenführen Quote selected text Reply Reply with quote
  







      

      



  

    Re: pwm modulation/demodulation
  


  

    

      von
      
        Lothar M.
            (Company: Titel)
        (lkmiller)
        (Moderator)
      
      


      
    


    

      
    

    

    

  
  


  

  Rate this post
  

  •
  
  ▲ useful 
  

  ▼ not useful 
  		
  

  


  

      
Did you simulate your design? How does the testbench look like? And: 
what's the problem at all? What does not "happen"? What do you expect? 
And what do you get?

  


  




  

    Report post Edit Delete Quote selected text Reply Reply with quote
  







      

      



  

    Re: pwm modulation/demodulation
  


  

    

      von
      
        Manni (Guest)
      
      


      
    


    

      
    

    

    

  
  


  

  Rate this post
  

  •
  
  ▲ useful 
  

  ▼ not useful 
  		
  

  


  

      
I am again surprised, how complex a AB-decoding can be done. I never 
learned about that and therefor was very new to it, when I had to do it 
the first time. What I am doing:

I sample the incoming value with a frequency which is low enough, that 
bouncing has no effect anymore and decide, if the value changed. When it 
inreased or had an overrun, I am adding 1 to my result, in the other 
case i substracted one. Allways worked sufficiently.

  


  




  

    Report post Edit Delete Quote selected text Reply Reply with quote
  








    

    

       Watch this topic

      |
         Disable multi-page view

    

        


Please log in before posting. Registration is free and takes only a minute.



  Existing account

  


  
  

  
    

      

        
          
        
        
          
        
      

      

        
          
        
        
          
        
      

    


    
    
    





  Do you have a Google/GoogleMail account? No registration required!

  Log in with Google account
  





  No account? Register here.