Abstract: An apparatus for decoding data includes a decoder circuit operable to apply a decoding algorithm to a decoder input to yield a codeword, a convergence detection circuit operable to determine whether parity checks are satisfied by the decoder input and to identify unsatisfied parity checks in the decoder circuit, and a symbol flipping controller operable to change values of at least one symbol in the decoder input based on information about the unsatisfied parity checks. The decoder circuit is restarted to process the decoder input with the changed values. The information about the unsatisfied parity checks is obtained at each of a number of local decoding iterations in the decoder circuit.