Help with Eye diagram of USB Full Speed Drivers with PRBS

[bharatsmile2007]

Eye diagram help...

Hi all....

I have given USB Full Speed Drivers a PRBS with bit time of 83n and 127bits. As USB Io is a differential output,the out pins shown in the image are DP_OUT ans DM_OUT.

when i generated the Eye diagram for 2 output pins separately with Time base as 83nsec and got the below eye...As you can see the eye is not complete,can any one let me know whats wrong with the simulation or the eye measurement...

Thanks again...

 

[coolstuff07]

Re: Eye diagram help...

Dear,

First take more number of cycles and sample after every two cycles to see complete eye.

Bye.

 

[karesz]

Eye diagram help...

Hi coolstuff07,
sorry, you can sample so much as you wish, the edges are wrong & it will not change...
K.