Estimating failed bit count

A storage device comprising:

• a controller;
• and
• a memory coupled to the controller,
• wherein the controller is configured to perform operations including:
• performing a read operation on the memory to obtain a codeword;
• performing error decoding on the codeword with an error decoder to generate an initial checksum;
• determining that the initial checksum of the codeword exceeds a checksum saturation threshold corresponding to an error correction capability of the error decoder;
• and
• determining a failed bit count (FBC) estimation of the codeword based on a dataset containing correlations between decoding information and a set of FBCs, wherein the dataset is obtained by:
• for each FBC in the set of FBCs:
• injecting the FBC number of errors into a training codeword;
• performing a plurality of decoding iterations on the training codeword using the error decoder;
• and
• recording, in the dataset, the decoding information for each decoding iteration.

A non-transitory computer readable medium storing code that, when executed by a controller, causes the controller to perform operations including:

• performing a read operation on a memory to obtain a codeword;
• performing error decoding on the codeword with an error decoder to generate an initial checksum;
• determining that the initial checksum of the codeword exceeds a checksum saturation threshold corresponding to an error correction capability of the error decoder;
• and
• determining a failed bit count (FBC) estimation of the codeword based on a dataset containing correlations between decoding information and a set of FBCs, wherein the dataset is obtained by:
• for each FBC in the set of FBCs:
• injecting the FBC number of errors into a training codeword;
• performing a plurality of decoding iterations on the training codeword using the error decoder;
• and
• recording, in the dataset, the decoding information for each decoding iteration including:
• a total number of bits flipped by the error decoder from an initial decoding iteration;
• or
• a checksum computed for the corresponding decoding iteration.