A computer system in a fault-tolerant configuration employs three identical CPUs executing the same instruction stream, with two identical, self-checking memory modules storing duplicates of the same data. Memory references by the three CPUs are made by three separate busses connected to three separate...http://www.google.com.tw/patents/US5146589?utm_source=gb-gplus-share專利 US5146589 - Refresh control for dynamic memory in multiple processor system
