I ran transient analysis for ring oscillator in cadence for several times and the results are very strange.
First, stop time is 20us there is an oscillation.
Next, stop time is 40us there is NO oscillation at all.
Is there something with that?
How did you set accuracy of the simulation?
Try to set maxstep in transient analysis few time less than Tosc (for example Tosc/10) .
Also, if you don't use initial condition or kickstart elements, place it to the your design.
Thanks for the help.
I just set these parameters:
stop time: 40u
Accuracy Defaults: moderate
Try to set maxstep in transient analysis few time less than Tosc (for example Tosc/10) .
Also, if you don't use initial condition or kickstart elements, place it to the your design.