SystemC vcd trace file cannot display the waveform

[krishna]

Hi All,

 I am starting the practical implementation of systemc code for 4 bit counter using d flip flop. It works properly as it is, But the problem is with the vcd trace file. The main module produces a vcd file of type .vcd format but when i tried to open it in the gtkwave viewer, the vcd file cannot be opened. There is no error message also for debugging the problem.

My systemc code is given below

//dff.cpp
 
#include <systemc.h>
 
SC_MODULE (dff) {
    sc_in <bool> clk;
    sc_in <bool> din;
    sc_out <bool> dout,;
 
    void dff_method()
    {
     	dout=din;
    }
    
    SC_CTOR (dff) {
        SC_METHOD (dff_method);
            sensitive_pos << clk;
    }
}

//main.cpp
 
#include <systemc.h>
#include "dff.cpp"
 
int sc_main(int argc, char* argv[])
{
sc_core::sc_report_handler::set_actions( "/IEEE_Std_1666/deprecated",
                                           sc_core::SC_DO_NOTHING );
sc_set_time_resolution(100, SC_PS);
sc_signal<bool> din1, dout1;
sc_signal<bool> din2, dout2;
sc_signal<bool> din3, dout3;
sc_signal<bool> din4, dout4;
sc_signal<bool> en;
sc_signal<bool> clk;
 
int i;
    
dff dff1("dff");
dff1.din(din1);
dff1.dout(dout1);
dff1.clk(clk);
 
dff dff2("dff");
dff2.din(din2);
dff2.dout(dout2);
dff2.clk(clk);
 
dff dff3("dff");
dff3.din(din3);
dff3.dout(dout3);
dff3.clk(clk);
 
dff dff4("dff");
dff4.din(din4);
dff4.dout(dout4);
dff4.clk(clk);
 
sc_trace_file *fp;                    // VCD file
fp=sc_create_vcd_trace_file("wave");
sc_trace(fp,clk,"clk");               // signals
sc_trace(fp,din1,"en");
sc_trace(fp,dout1,"dout_one");
sc_trace(fp,dout2,"dout_two");
sc_trace(fp,dout3,"dout_three");
sc_trace(fp,dout4,"dout_four");
en=1;
for(i=0;i<40;i++)
{
din1=en^dout1;
din2=((en&dout1)^dout2);
din3=(((en&dout1)&dout2)^dout3);
din4=((((en&dout1)&dout2)&dout3)^dout4);
clk=0;
sc_start(1, SC_NS);
clk=1;
sc_start(1, SC_NS);
cout<<" @ "<<sc_time_stamp()<<" dout: "<<dout4<<dout3<<dout2<<dout1<<endl;
}   
sc_close_vcd_trace_file(fp);
return 0;
}

and the vcd file is shown as below when opened in vi editior:

$date
     Oct 13, 2014       21:46:55
$end
 
$version
 SystemC 2.3.1-Accellera --- Oct  8 2014 22:37:31
$end
 
$timescale
     100 ps
$end
 
$scope module SystemC $end
$var wire    1  aaaaa  clk       $end
$var wire    1  aaaab  en       $end
$var wire    1  aaaac  dout_one       $end
$var wire    1  aaaad  dout_two       $end
$var wire    1  aaaae  dout_three       $end
$var wire    1  aaaaf  dout_four       $end
$upscope $end
$enddefinitions  $end
 
$comment
All initial values are dumped below at time 0 sec = 0 timescale units.
$end
 
$dumpvars
0aaaaa
0aaaab
0aaaac
0aaaad
0aaaae
0aaaaf
$end
 
#10
1aaaaa
 
#20
0aaaaa
1aaaab
 
#30
1aaaaa
1aaaac
 
#40
0aaaaa
0aaaab
 
#50
1aaaaa
0aaaac
1aaaad
 
#60
0aaaaa
1aaaab
 
#70
1aaaaa
1aaaac
 
#80
0aaaaa
0aaaab
 
#90
1aaaaa
0aaaac
0aaaad
1aaaae
 
#100
0aaaaa
1aaaab
 
#110
1aaaaa
1aaaac
 
#120
0aaaaa
0aaaab
 
#130
1aaaaa
0aaaac
1aaaad
 
#140
0aaaaa
1aaaab
 
#150
1aaaaa
1aaaac
 
#160
0aaaaa
0aaaab
 
#170
1aaaaa
0aaaac
0aaaad
0aaaae
1aaaaf
 
#180
0aaaaa
1aaaab
 
#190
1aaaaa
1aaaac
 
#200
0aaaaa
0aaaab
 
#210
1aaaaa
0aaaac
1aaaad
 
#220
0aaaaa
1aaaab
 
#230
1aaaaa
1aaaac
 
#240
0aaaaa
0aaaab
 
#250
1aaaaa
0aaaac
0aaaad
1aaaae
 
#260
0aaaaa
1aaaab
 
#270
1aaaaa
1aaaac
 
#280
0aaaaa
0aaaab
 
#290
1aaaaa
0aaaac
1aaaad
 
#300
0aaaaa
1aaaab
 
#310
1aaaaa
1aaaac
 
#320
0aaaaa
0aaaab
 
#330
1aaaaa
0aaaac
0aaaad
0aaaae
0aaaaf
 
#340
0aaaaa
1aaaab
 
#350
1aaaaa
1aaaac
 
#360
0aaaaa
0aaaab
 
#370
1aaaaa
0aaaac
1aaaad
 
#380
0aaaaa
1aaaab
 
#390
1aaaaa
1aaaac
 
#400
0aaaaa
0aaaab
 
#410
1aaaaa
0aaaac
0aaaad
1aaaae
 
#420
0aaaaa
1aaaab
 
#430
1aaaaa
1aaaac
 
#440
0aaaaa
0aaaab
 
#450
1aaaaa
0aaaac
1aaaad
 
#460
0aaaaa
1aaaab
 
#470
1aaaaa
1aaaac
 
#480
0aaaaa
0aaaab
 
#490
1aaaaa
0aaaac
0aaaad
0aaaae
1aaaaf
 
#500
0aaaaa
1aaaab
 
#510
1aaaaa
1aaaac
 
#520
0aaaaa
0aaaab
 
#530
1aaaaa
0aaaac
1aaaad
 
#540
0aaaaa
1aaaab
 
#550
1aaaaa
1aaaac
 
#560
0aaaaa
0aaaab
 
#570
1aaaaa
0aaaac
0aaaad
1aaaae
 
#580
0aaaaa
1aaaab
 
#590
1aaaaa
1aaaac
 
#600
0aaaaa
0aaaab
 
#610
1aaaaa
0aaaac
1aaaad
 
#620
0aaaaa
1aaaab
 
#630
1aaaaa
1aaaac
 
#640
0aaaaa
0aaaab
 
#650
1aaaaa
0aaaac
0aaaad
0aaaae
0aaaaf
 
#660
0aaaaa
1aaaab
 
#670
1aaaaa
1aaaac
 
#680
0aaaaa
0aaaab
 
#690
1aaaaa
0aaaac
1aaaad
 
#700
0aaaaa
1aaaab
 
#710
1aaaaa
1aaaac
 
#720
0aaaaa
0aaaab
 
#730
1aaaaa
0aaaac
0aaaad
1aaaae
 
#740
0aaaaa
1aaaab
 
#750
1aaaaa
1aaaac
 
#760
0aaaaa
0aaaab
 
#770
1aaaaa
0aaaac
1aaaad
 
#780
0aaaaa
1aaaab
 
#790
1aaaaa
1aaaac

As you can see the comment in the tracefile

 

 

1. $comment
2. All initial values are dumped below at time 0 sec = 0 timescale units.
3. $end

So is this the reason the vcd file cannot be opened? if yes, what changes do i need to do in the main module to get waveform?

 

 

Please help me how to proceed to the problem solution.

 

Thanks in advance.

 

[kartikkg]

SC_MODULE (dff) {
sc_in <bool> clk;sc_in <bool> din;sc_out <bool> dout,;
void dff_method()
{    dout=din;}
SC_CTOR (dff) {SC_METHOD (dff_method);sensitive_pos << clk;}};

Add the semi colon at the end. I compiled this code It works fine . In GTK-Wave you have to click on the System C icon below SST and then add all the signals which appear on the window below .

[krishna]

Kartikkg,

 

Thanks for clarification.

 

I got the waveform with your guidance...