I am new to cadence virtuoso/spectre. I want to design an ADC for which I have written some components through verilog A containing their respective noise models implemented through white_noise and flicker_noise functions.
Now how to activate those sources in spectre simulation ? It's only active in small signal analysis as far as I know. However I want noise to be present along with the main signal so that I can measure SNR etc using calculator function.So which type of analysis to use: tran or noise ? and how (few lines of analysis statement will help)
Moreover, from cadence virtuoso manual I found that we can perform small signal analysis during transient analysis, by using below command:
Name tran stop=stop actimes=time acnames=name
However I got a syntax error of "ERROR (SPECTRE-16062): Output of circuit is not specified." on running below code snippet on a simple test circuit :
tran tran stop=4u write="spectre.ic" writefinal="spectre.fc" \
annotate=status maxiters=5 actimes=[2u] acnames=[noise1]
noise1 noise start=2u stop=2.1u
finalTimeOP info what=oppoint where=rawfile
I stuffed another "info what=oppoint" statement between 2nd and 3rd line, still same error. Here my understanding is tran analysis stops at 2u and till 2.1 the simulator will run noise analysis (if wrong please correct me). I am still trying to debug this and it may be a plain syntax error. However can someone please answer above questions and guide me through the right approach.
Thanks a lot!
Use transient analysis. (transient noise)
Use the latest versions of MMSIM. (Note that there were some issues with the psp103 trannoise model which are being fixed in MMSIM11.1 ISR23.)
If you are using IC615…
You may want to check out the Spectrum Assistant Appnote at:
If using IC614, use the spectrumMeas function in ADE-L/XL
You can also look at the OCEAN reference manual (information on spectrum function):
And also the spectrumMeas function, see Appendix D of the ViVA tool user guide: