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Sampling a waveform at non-periodic times using Calculator functions

gvita

Hi,

I would like to sample a waveform y(t) at the rising edges of another waveform z(t) that is not periodic.

Do you know if it is possible to write an expression with the calculator functions? Because "sample" works only with periodic times.

I was thinking if one can use the "foreach" SKILL function and I tried this expression in the calculator:

foreach(x cross(clip(VT("/BUCK/Iana/Iphase/goSw1_CP") 40u 45u) 2.5 1 "rising" nil nil  ) value(VT("/VOUT0") x    ?extrapolate nil ))

but unfortunately it does not work.

Do you have any suggestion?

thanks in advance

  • Frank Wiedmann

    I would probably use a Verilog-A module similar to sh2 from http://www.designers-guide.org/VerilogAMS/functional-blocks/sh/sh.va. If you just have to deal with jitter, you can then sample the resulting signal with periodic times in the calculator. Otherwise, you could modify the module so that it writes the sampled values to a file. The cross function in the module forces the simulator to place simulation timepoints at the crossings, which might significantly improve the accuracy of your results.

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