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tie jitter function

Karev11

Hi,

I wonder if there's function or expression based on existing functions to check tie type of jitter. To elaborate, the goal is to check corresponding edge  difference from clk_sim (from simulation) and clk_ref (based on ideal clock). 

The expression of jitter should be something like: jit = cross(VT("/vout_sim") 0.5 1 "rising"  t "time"  nil ) - N*Tref, in which cross() gives edge of clock_sim, Tref is known (1/fref), but as you can see, I need expression for N.   I applied xval() function to cross() result, but it still gives rising edge time, instead of the index of the clock edge.

any idea?

thanks,

Kevin

  • Hi Kevin,

    You can use the delay function in the calculator to do this. Measure one signal against the ideal clock signal (assuming you have that in your circuit), and use the multiple occurrences feature.

    Alternatively you could use the abEyeCross.il function in this article. (abEyeCross plots versus the crossing number, and doesn't require a reference clock signal - you tell it the period yourself).

    Regards,

    Andrew.

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