Parity error recovery method for string search CAM

摘要

Data is compressed using content addressable memory without disruption despite error using a plurality of content addressable memories to detect sequentially repeating data elements of the data. Compression information is generated for each sequence of repeating data elements that repeat for at least a compression threshold without any one of the plurality of content addressable memories generating an indication of an error for a matching content addressable memory entry. Individual data elements are output for each of the data elements that do not repeat for the compression threshold. Compression information is generated for each sequence of repeating data elements that repeat for at least the compression threshold and then generating a currently searched data element that matches the repeating data elements when any one of the plurality of content addressable memories generates an indication of an error for a content addressable memory entry that matches the currently searched data element.

主权项

1. A device comprising:
a plurality of content addressable memories, wherein each content addressable memory of the plurality of content addressable memories includes error detection circuitry for each word entry of the content addressable memory, the error detection circuitry configured to generate an error signal when an error is detected for the word entry and content of the word entry matches search data; counting circuitry that counts a number of sequential repeats of search data detected by at least one of the plurality of content addressable memories without an error; compression circuitry that generates compression information for a sequentially repeating search data that repeats for a compression threshold; a data path to carry search data in accordance with a number of stages for the plurality of content addressable memories to search for a match with the search data; and selection circuitry that selects input from the data path when the error detection circuitry of any one of the plurality of content addressable memories generates an error signal, that selects input from the compression circuitry when none of the error detection circuitries of the plurality of content addressable memories generates an error signal over a span of a detected sequence of repeating search data that repeats for a compression threshold, and that outputs a selected input.