Jared Zerbe, Director of Engineering, Rambus, Inc.
Qi Lin, Member of Technical Staff, Rambus, Inc.
Vladimir Stojanovic, Principal Engineer, Rambus, Inc.
Andrew Ho, Senior Member of Technical Staff, Rambus, Inc.
Ravi Kollipara, Signal-Integrity Manager, Rambus, Inc.
Frank Lambrecht, Senior Signal-Integrity Engineer, Rambus, Inc.
Carl Werner, Circuit Design Manager, Rambus, Inc.

It has been shown that there are significant variations in backplane interconnect over environmental variations. The question remains: how to best set equalization coefficients where both high performance & low cost are required? Three different methods are discussed in detail: table-based lookup, adapt on power-up, and continuous live-adaptation. The merits and difficulties of implementing each method in high-speed serial links are discussed. Measured silicon + system results for the methods are shown for materials ranging from FR-4 to Rogers. Measured data including temperature and humidity variations and effects on system margins are shown for data rates from 2.5-6.25Gb/s.