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Is it possible to read a noise file from Verilog-A?
I would like to add a known noise shape to a model of a vdc voltage source modeled by Verilog-A.
(I need to read data from a file and pass them to noise_table)
thank you very much
How about this code below. A simple command line testcase would be:
// noise_from_file.scs I1 (n1) noise_from_file filename="noise.dat" //debug=1r1 (n1 0) resistor r=1k isnoisy=noahdl_include "noise_from_file.va"noise (n1 0) noise start=1 stop=1G dec=10
With this as the noise.dat:
module noise_from_file (op);
parameter string filename="noise.dat";
if (debug) $debug("Data is %d %g %g",retval,frq,val);
V(op) <+ noise_table(noisetab);
In reply to Andrew Beckett:
Many thanks, Andrew
In reply to Aldo2:
Starting from your suggestions I wrote the following code:
module TEST(VOUT,ADJ); inout VOUT, ADJ; electrical VOUT, ADJ; integer voutPar,file,i,retVal; real vthr,noiseFrq,noiseVal,voutVal; string filename,temp; real noisetab[0:1000];
analog begin vthr=0.1; if(V(ADJ)>vthr) voutPar=1; else voutPar=0; case (voutPar) 0: begin filename="TEST_1V.csv"; voutVal =1; end 1: begin filename="TEST_2V.csv"; voutVal =2; end endcase file=$fopen(filename,"r"); $fscanf(file,"%s",temp); $display("%s",temp); i=0; retVal=$fscanf(file,"%f %f",noiseFrq,noiseVal); while(retVal==2) begin noisetab[i]=noiseFrq; i=i+1; noisetab[i]=noiseVal; i=i+1; retVal=$fscanf(file,"%f %f",noiseFrq,noiseVal); end $fclose(file); V(VOUT) <+ voutVal+noise_table(noisetab); endendmodule
If voutPar=1, I get the following error message:
Internal error found in spectre during DC analysis `dcOp'. Encountered a critical error during simulation. Submit a Service Request via Cadence Online Support, including the netlist, the Spectre log file, the behavioral model files, and any other information that can help identify the problem. FATAL (SPECTRE-18): Segmentation fault.
Whereas if voutPar=0 it works.
If I make load the same file in both cases:
case (voutPar) 0: begin filename="TEST_1V.csv"; voutVal =1; end 1: begin filename="TEST_1V.csv"; voutVal =2; end endcase
the code works