I have been trying to plot eye diagrams in cadence. The command eyediagram(signal,start,stop,period) is the format. But i am not able to control the no of eyes in my diagram. Say i run my simulation from 0 to 10u and my input clk is 5Ghz, typically to get a SINGLE EYE, i should give 200p as period rite ? I have added a 25p, 25p rise time fall time for it. But the thing seems going crazy.
Any ideas whats bugging ?
I adjusted my start time and i got something like this.
This is what i wanted. When i try to confirm the same design in matlab (extracting the data to matlab and using commscope.eyediagram), i am not getting the same eye, there are a set of parameters,
eyeobj= commscope.eyediagram('SamplingFrequency', 10e9, ... 'SymbolsPerTrace', 2,... 'SamplesPerSymbol', 10, ... 'MinimumAmplitude', -1, ... 'MaximumAmplitude', 1, ... 'AmplitudeResolution', .001, ... 'MeasurementDelay', 0, ... 'PlotType', '2D Line', ... 'PlotTimeOffset', 0, ... 'RefreshPLot','on',... 'ColorScale', 'linear');eyeobj.update(data);
Basically i am trying to convince that the eye diagram plot from matlab and cadence are one and the same. But what are the parameters that i have to additionally give to see the same eye diagram. I have given samples per symbol as 10, but in my earlier post, i have asked reg sampling frequency in cadence, you had told that there is no such thing (http://www.cadence.com/community/forums/T/23319.aspx). In that case what will be my Samples per Symbol ? I hope i am clear
Currently with the given parameters, i am getting a matlab plot like this which is not the same as the cadence one, atleast in first look.