using gtkwave

[re1418ma]

hi i installed systemc in microsoft visual studio and i wrote some code now i want to see output wave in gtkwave

how should i export my code to see waves in gtkwave?

 

[Eyck]

Actually SystemC provided sc_trace(...) functions where you register your signals and variables for tracing. Running the simulation yields a .vcd file which you can open in gtkwave.

You may have a look into https://github.com/Minres/SystemC-Components-Test/blob/master/examples/transaction_recording/scv_tr_recording_example.cpp

In sc_main() you will find sc_trace_file *tf = sc_create_vcd_trace_file("my_db");

sc_trace_file *tf = sc_create_vcd_trace_file("my_db");

This opens the waveform database. At the end you have to call

sc_close_vcd_trace_file(tf);

to properly close the database. 'tf' is a handle to the database, if you follow the code you will see how to trace signals (or variables),

Best

 

[re1418ma]

thanks for the reply i wrote this code

#include "systemc.h"

SC_MODULE(and_gate){

 sc_in<bool> a, b;
 sc_out<bool> c; 

 void and_gate_p(){
  next_trigger(5, SC_NS);
  c.write(a.read() & b.read());
 }
 SC_CTOR(and_gate){
  SC_METHOD(and_gate_p);
  sensitive << a << b;
 }
};

int sc_main(int argc, char* argv[]){
 sc_signal<bool> a, b, c;
 and_gate and1("and_gate_and1");
 and1.a(a);
 and1.b(b);
 and1.c(c);

 sc_trace_file *tf = sc_create_vcd_trace_file("and_gate");

 tf->set_time_unit(1, SC_NS);

 sc_trace(tf, a, "a");
 sc_trace(tf, b, "b");
 sc_trace(tf, c, "c");

 a = 0;
 b = 0;
 sc_start(1.0, SC_NS);

 a = 0;
 b = 1;
 sc_start(1.0, SC_NS);

 a = 1;
 b = 0;
 sc_start(1.0, SC_NS);

 a = 1;
 b = 1;
 sc_start(1.0, SC_NS);

 sc_stop();

 
 sc_close_vcd_trace_file(tf);

 cout << "Finished at time " << sc_time_stamp() << endl;

 return 0;
}

and still  getting error and i have no idea how to solve the problem

[Roman Popov]

2 hours ago, re1418ma said:

thanks for the reply i wrote this code

..

Your code is not correct.  Why did you put   next_trigger(5, SC_NS) inside a method? Remove it, and you will get correct waveform for and gate.

[re1418ma]

the gate must have delay of 5ns

removing that statement and still getting error

[Roman Popov]

Quote

removing that statement and still getting error

I've removed  next_trigger and simulated your code. Check attached waveform.

Quote

the gate must have delay of 5ns

Check how to model delay line here:

 

[re1418ma]

thanks for reply i removed next_trigger and code build succeeded this seems stupid question where vcd trace file located?

[Roman Popov]

Just now, re1418ma said:

thanks for reply i removed next_trigger and code build succeeded this seems stupid question where vcd trace file located?

In the working directory (active directory when you launch the executable). Search for "and_gate.vcd"

[re1418ma]

i've searched whole my computer and only found object and source code

[Roman Popov]

3 minutes ago, re1418ma said:

i've searched whole my computer and only found object and source code

I don't work on Windows. But as far as I remember executable should be somewhere in project sub-directory called "Release" or "Debug". Sorry, can't help you more here.

[re1418ma]

you helped a lot sir and for final question i read the post about delay and make some changes

 #include "systemc.h"

SC_MODULE(and_gate){

 sc_in<bool> a, b;
 sc_out<bool> c;

 void and_gate_p(){
     while(true){
         wait(5,SC_NS);
  c.write(a.read() & b.read());
     }
 }
 SC_CTOR(and_gate){
  SC_THREAD(and_gate_p);
  sensitive << a << b;
 }
};

int sc_main(int argc, char* argv[]){
 sc_signal<bool> a, b, c;
 and_gate and1("and_gate_and1");
 and1.a(a);
 and1.b(b);
 and1.c(c);

 sc_trace_file *tf = sc_create_vcd_trace_file("and_gate");

 tf->set_time_unit(1, SC_NS);

 sc_trace(tf, a, "a");
 sc_trace(tf, b, "b");
 sc_trace(tf, c, "c");

 a = 0;
 b = 0;
 sc_start(1.0, SC_NS);

 a = 0;
 b = 1;
 sc_start(1.0, SC_NS);

 a = 1;
 b = 0;
 sc_start(1.0, SC_NS);

 a = 1;
 b = 1;
 sc_start(1.0, SC_NS);

 sc_stop();

 
 sc_close_vcd_trace_file(tf);

 cout << "Finished at time " << sc_time_stamp() << endl;

 return 0;
}

is it correct?

[Roman Popov]

3 minutes ago, re1418ma said:

SC_MODULE(and_gate){

 sc_in<bool> a, b;
 sc_out<bool> c;

 void and_gate_p(){
     while(true){
         wait(5,SC_NS);
  c.write(a.read() & b.read());
     }
 }
 SC_CTOR(and_gate){
  SC_THREAD(and_gate_p);
  sensitive << a << b;
 }
};

is it correct?

No. If you want to model a gate with a delay to output you will need to attach a delay line (check AmeyaVS code on a thread I've referenced before) to output signal.  

But first I suggest you to learn what each line in your code does, and understand why it does not work.