Described are systems that employ configurable on-die termination elements that allow users to select from two or more termination topologies. One topology is programmable to support rail-to-rail or half-supply termination. Another topology selectively includes fixed or variable filter elements, thereby...http://www.google.com.au/patents/US7577789?utm_source=gb-gplus-sharePatent US7577789 - Upgradable memory system with reconfigurable interconnect
