Soft error protection for content addressable memory

摘要

In one embodiment of the invention, a method for protecting a content addressable memory is disclosed. The method includes storing a marker bit associated with each data block stored in a random access memory (RAM), states of the marker bit representing whether the data block was recently read from the RAM or recently written into the RAM; receiving a client address pointing to a starting address of a data block stored in the RAM; comparing the client address against one or more addresses stored in a content addressable memory (CAM) to determine a hit indicating the client address was stored in the CAM or a miss indicating the client address was not stored in the CAM; and in response to a miss, the method further includes checking a state of the marker bit associated with the data block pointed to by the client address.

主权项

1. A method comprising:
storing a marker bit associated with each data block stored in a random access memory (RAM), states of the marker bit representing whether the data block was recently read from the RAM or recently written into the RAM; generating a first state of the marker bit associated with each data block written into the RAM; receiving a client address pointing to a starting address of a data block stored in the RAM; comparing the client address against one or more addresses stored in a content addressable memory (CAM) to determine a hit indicating the client address was stored in the CAM or a miss indicating the client address was not stored in the CAM; updating the first state to a second state opposite the first for each marker bit associated with each data block read out of the RAM; and in response to a miss, checking a state of the marker bit associated with the data block pointed to by the client address.