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SPECTRE PNOISE and JITTER calculations

RRThomas

Hello,

I am trying to find out the clk-clk jitter performance of my VCO and after reading the inputs from the forum & Jitter_AN.pdf,  I could set up the simulation.

But the jitter expression, (drplRFJc ?from 1000 ?to 750000000 ?k 1 ?multiplier 1 ?result "pnoise" ?unit "UI") works with a single corner , single Vtune simulation. It annotates the Jc value into the graph. It returns the value in calculator also.

But it fails ( no annotation, calculator also fails to return te jitter value)  when I do a corner simulation.

It also fails when I do a single corner, Vtune sweep. So, in short it seems the jitter calculation fails when I have a family of waves.

I thought I could use famMap function, but couldn't manage to do it.

Could you please help me to solve this issue ?

Best Regards,

Thomas

Parents

  • Hi Andrew,

    I tried the famMap.

    famMap('drplRFJc ?from 1000 ?to 750000000 ?k 1 ?multiplier 1 ?result "pnoise" ?unit "UI")

    and the error is,

    *Info* The input waveform has a logarithmic X scale. This scale might not be preserved after the waveform is flipped.

    expression evaluation failed: val is not legal.

    expression evaluation failed: famMap('drplRFJc ?from 1000 ?to 750000000 ?k 1 ?multiplier 1 ?result "pnoise" ?unit "UI")

    "(\"quotient\" 0 t nil (\"*Error* quotient: can't handle (3141.593 / (7.479339e+08 2.718515e+09))\"))"

    So seems some problem is there. I shall report it to customer support.

    Best Regards,

    Thomas

Reply

  • Hi Andrew,

    I tried the famMap.

    famMap('drplRFJc ?from 1000 ?to 750000000 ?k 1 ?multiplier 1 ?result "pnoise" ?unit "UI")

    and the error is,

    *Info* The input waveform has a logarithmic X scale. This scale might not be preserved after the waveform is flipped.

    expression evaluation failed: val is not legal.

    expression evaluation failed: famMap('drplRFJc ?from 1000 ?to 750000000 ?k 1 ?multiplier 1 ?result "pnoise" ?unit "UI")

    "(\"quotient\" 0 t nil (\"*Error* quotient: can't handle (3141.593 / (7.479339e+08 2.718515e+09))\"))"

    So seems some problem is there. I shall report it to customer support.

    Best Regards,

    Thomas

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