Patent attributes
The present disclosure generally relates to storage devices, such as solid state drives. A storage device comprises a controller comprising a controller error correction code (ECC) engine and a storage unit comprising a plurality of dies. Each of the dies comprise a die ECC engine. When user data is received, the controller ECC engine generates first ECC/error detection code (EDC) data. The user data and the first ECC/EDC data is sent to a die for storage as a code word. The die ECC engine generates second ECC/EDC data for the code word in granular portions. The second ECC/EDC data is used to correct bit errors in one or more code words up to a threshold value. When the number of bit errors exceeds the threshold value, the failed code words are sent to the controller ECC engine for correction.
