High reliability content-addressable memory using shadow content-addressable memory
AssigneeInternational Business Machines Corporation
InventorsKevin A. Batson, Geordie M. Braceras, Robert E. Busch, Gary S. Koch
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Abstract
A high-reliability content-addressable memory using a shadow content-addressable memory (CAM) array in parallel with a primary CAM array to increase the reliability of CAM searches. The reliability of CAM searches has been less than desired because of random environmental influences that corrupt data. The shadow CAM is written, read, and searched in parallel with the primary CAM. The search results from the parallel searches are compared and, if identical, are declared valid. If the search results are not equal, corrective action is initiated. The high-reliability content-addressable memory may be used with or without priority encoders.
Claims18
A method for searching content-addressable memory comprising:
- providing a first content-addressable memory having a first content-addressable memory array;
- providing a second content-addressable memory having a second content-addressable memory array;
- storing data into the first and second content-addressable memories;
- performing a search for a comparand in the first content-addressable memory to obtain a first address for data matching the comparand;
- performing the search for the comparand in the second content-addressable memory to obtain a second address for data matching the comparand;
- comparing the first address with the second address;
- and
- validating the search result if the first address and the second address are equivalent.
Dependencies are inferred from the claim text.