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https://designers-guide.org/forum/YaBB.pl Design Languages >> Verilog-AMS >> usage of noise_table https://designers-guide.org/forum/YaBB.pl?num=1351249474 Message started by Richardsim on Oct 26th, 2012, 4:04am |
Title: usage of noise_table Post by Richardsim on Oct 26th, 2012, 4:04am I am trying to use the noise_table noise function using the module included below. The ac simulation result, connecting the tnoisesourcemin terminal to gnd and the tnoisesourceplus terminal to a simple beam stiffness model, is a zero displacement magnitude output for all frequencies. I am working in Virtuoso 6.1.4. Does anyone have any suggestions what I'm doing wrong? Many thanks in advance, Richard //Verilog-AMS HDL for ..... `include "constants.vams" `include "disciplines.vams" module NoiseTable (tnoisesourceplus,tnoisesourcemin); inout tnoisesourceplus,tnoisesourcemin; kinematic tnoisesourceplus,tnoisesourcemin; // mechanical properties // parameter real mag = 0.000001; // N/m // noise source amplitude information parameter real f1 = 0.001; //Hz parameter real A1 = 0.000001; //m parameter real f2 = 0.01; //Hz parameter real A2 = 0.000001; //m parameter real f3 = 0.1; //Hz parameter real A3 = 0.000001; //m parameter real f4 = 1; //Hz parameter real A4 = 0.0000001; //m parameter real f5 = 100; //Hz parameter real A5 = 0.000000001; //m analog begin Pos(tnoisesourceplus,tnoisesourcemin) <+ noise_table({f1,A1, f2,A2, f3,A3,f4,A4, f5,A5}, "surface"); end endmodule |
Title: Re: usage of noise_table Post by Geoffrey_Coram on Oct 29th, 2012, 5:57am What you posted looks OK to me; could be the beam stiffness model. I have three suggestions: 1) try the NoiseTable module by itself -- just leave the tnoisesourceplus floating, since you're setting the "potential" (Pos) for the kinematic discipline, there shouldn't be any singular matrix problems 2) try using a ' before the { in the call; I think the latest LRM requires a single-quote ' before array literals 3) try using numbers, rather than parameters, in the array (just to see if that's the problem -- I understand you want to have parameters) |
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