Error Propagation in Channel Operating Margin

Channel Operating Margin (COM) is an efficient method to evaluate high speed interconnects. Two 100GBASE-KP4 backplanes are simulated and compared to give a brief introduction of COM. The pulse responses of COM are validated by comparing to the transient circuit simulation. A generic model for error propagation is proposed based on the COM results and Markov Chain. It shows that backplane designs with large Decision Feedback Equalizer (DFE) taps can have significant error propagation effect, which degrades the system performance further.