Decoder circuit, flash memory controller, and decoding method

Abstract

A decoding method includes: receiving and storing input data as a channel value in a channel value memory in a form of codeword; generating a posterior probability and a variable-to-check message according to a specific chunk of the channel value; converting the variable-to-check message from variable node domain into check node domain to generate a converted variable-to-check message; using a check node unit to generate a check-to-variable message according to the converted variable-to-check message; converting the check-to-variable message from check node domain into variable node domain to generate a converted check-to-variable message; determining whether to flip at least one bit of the specific chunk according to the posterior probability; and, determining whether to ignore and skip execution of decoding calculation for the specific chunk in a next iterative decoding operation according to whether a decoding calculation result in a current iterative decoding operation matches with a specific condition.