Abstract: Data in a system having dynamic random access memories (DRAM's) is preserved despite loss of the primary source of electrical power to that system. A Flash RAM and a small auxiliary power source are employed by a controller independent of the system to transfer the DRAM contents to the Flash RAM immediately upon loss of primary system power. The data is also automatically returned to the DRAM after return of primary power with special data signals or sequences being utilized in a multiple controller environment so as to award the complete data recovery function to the first controller to demand attention.
Type:
Grant
Filed:
September 28, 1995
Date of Patent:
August 25, 1998
Assignee:
EMC Corporation
Inventors:
William A. Brant, Michael E. Nielson, Edde Tin-Shek Tang