counting output pulse(project)

[Altera_Forum]

Hi everyone,  

 I would like to count the number of pulse outputting to a device, so that ,at some point, i can stop it from outputting. However i dont know how to do that..   I thought of using time to control the output signal, however it fails.  This question has been bothering me for 2-3 weeks, i still can't figure out. I hope you guys can help me. Thank you so much.   For more information,  I am actually building a system using FPGA to trigger the stepper motor in my lab. However, i want to stop the motor at some points, say 180 degree.  I have done all the calculation. In order to make it rotate 180 degree, i need to have 50 pulse outputting from FPGA.   Please help me. What should i do. Thank you

[Altera_Forum]

But why is it difficult to count 50 pulses. You need to explain the difficulty. are pulses equal in period?

[Altera_Forum]

kaz,  

 yes pulses are equal in period,  like,, i need to stop it at some point, say 50 pulses...however i dont know how to do it , u have any idea?

[Altera_Forum]

--- Quote Start ---  kaz,   yes pulses are equal in period,  like,, i need to stop it at some point, say 50 pulses...however i dont know how to do it , u have any idea?  --- Quote End ---    50 pulses each n clocks (per pulse period) then you need to count 0 ~ 50n-1. reset counter at start and then enable counter when pulse is high only.  I don't see what is so hard about it.

[Altera_Forum]

oh sorry, but i am just a beginner, i tried 

should i use "repeat"?   i can only use a counter to divide the frequency... and then i got stuck

[Altera_Forum]

Hi Sam, 

 Please use this as reference.  module pulse_atN(Clk, Reset, Pulse, N);    parameter WIDTH = 10;   input Clk, Reset;  input [WIDTH-1:0] N;   reg [WIDTH-1:0] Nlast;      reg [WIDTH-1:0] Count;    output Pulse;    assign Pulse = (Count == N-1) && (N != 0);      always @ (posedge Clk, posedge Reset)  begin : PULSE_GENERATOR  if(Reset)  Count <= 0;  else  begin  // nonblocking so check occurs with old Nlast  Nlast <= N;    if(Nlast != N)  Count <= 0;  else if(Count == N-1)  begin  Count <= 0;  Pulse = 1;   end  else  begin  Count <= Count + 1;  Pulse = 0;   end  end  end   endmodule

[Altera_Forum]

module pulse_atN(Clk, Reset, Pulse, N);  

  parameter WIDTH = 10;   input Clk, Reset;  input [WIDTH-1:0] N;   reg [WIDTH-1:0] Nlast;   reg [WIDTH-1:0] Count;    output Pulse;    assign Pulse = (Count == N-1) && (N != 0);    always @ (posedge Clk, posedge Reset)  begin : PULSE_GENERATOR  if(Reset)  Count <= 0;  else  begin  // nonblocking so check occurs with old Nlast  Nlast <= N;    if(Nlast != N)  Count <= 0;  else if(Count == N-1)  begin  Count <= 0;  Pulse = 1;  end  else  begin  Count <= Count + 1;  Pulse = 0;  end  end  end   endmodule

[Altera_Forum]

Hi Sam, 

 Please refer this example if might help.  http://www.edaboard.com/thread280011.html