Writing into a file in Verilog-A Model

Which errors (and when? on open, on writing, etc.) ?  Which version?  Please check the Forum guidelines for creating good posts.

Best regards,

Lawrence.

If the error you got was this:

 Error found by spectre during AHDL read-in.
    ERROR (VACOMP-2212): "fp=$fopen("/home/mac/MAT_CAD/X_MODEL/ref_edge.txt",a)<<--?          "
        "writingfile.va", line 15: Encountered undeclared identifier: a. Declare the identifier before using it.
    ERROR (VACOMP-2259): "end<<--? "
        "writingfile.va", line 17: syntax error.

Then it's because you didn't put quotes around the "a" (the append mode) and you omitted a semi-colon at the end of the line. If I change it to:

      fp=$fopen("/home/mac/MAT_CAD/X_MODEL/ref_edge.txt","a");

(I changed the path to something local so it worked in my location), it worked fine. Here's my complete example:

`include "disciplines.vams"

module writingfile(clk);
input clk;
electrical clk;
parameter real Vth=1.0;
parameter real dir=1.0;
parameter real ttol=1n;

real Cross_point;
integer fp;

analog begin
 @(initial_step) begin
     //fp=$fopen("/home/mac/MAT_CAD/X_MODEL/ref_edge.txt",a)         
     fp=$fopen("./ref_edge.txt","a");
     end

 
  @(cross(V(clk) - Vth, dir, ttol)) begin
                $strobe(" Cross Time = %e  \n", $abstime);
                Cross_point= $abstime ;

                $fwrite(fp,"%e \n",Cross_point);
      end 

end

endmodule

If I run this with this netlist:

//

V1 (clk 0) vsource type=pulse val0=0 val1=2 rise=1n fall=1n period=40n width=20n
W1 (clk) writingfile

ahdl_include "writingfile.va"

tran tran stop=200n

Then I get ref_edge.txt containing:

5.002500e-10
4.050025e-08
8.050025e-08
1.205003e-07
1.605003e-07

Kind Regards,

Andrew.

 Dear Andrew,

Thanks a lot !!

Kind Regards,

Dear Andrew,

It is actually writing into file. but the last data is not getting written into file.

I suspect may be it is becuase there is no $fclose() statement .

How this can be made at the end of the simulation .

Kind Regards,

 It will automatically be closed when the simulator exits, but if running from ADE you're probably running in "interactive" mode which means the simulator hasn't exited yet.

You could use @(final_step) to explicitly close the file at the end of the analysis.

Kind Regards,

Andrew.

Thanks a lot 

Kind Regards,

Dear Andrew,

Sorry, I am facing another issue in file writing.

The file is being closed at the end of the simulation by using $fclose().

But when I am strating the simulation again, the data is being appended to the previous data already in the file.

Like, OCEAN script, it should not append rather it should overwrite the file with the current simulation data.

Could you please tell why it is happening. If any further information is needed I can provide.

Kind Regards,

Change the second argument of $fopen to "w". "a" means append and "w" means write. 

Kind Regards,

Andrew