Since the IEEE 802.3bj 100 Gb/s Backplane Ethernet standard has been officially approved, Channel Operating Margin (COM) will likely become an important quality-evaluation method for SERDES links.

Although COM was preceded by a long history of eye/BER evaluation techniques, those methods have never been officially standardized. This whitepaper will outline the differences between COM and BER and present an analysis of the differences concluding with some real-life design examples.