Method and apparatus for decoding error correction code (ECC) code words. Reference voltages are used to extract a selected code word from a communication channel. The selected code word is processed by an ECC decoder, and an initial syndrome weight is determined indicative of unresolved parity errors. A coarse search operates to concurrently adjust, over a first succession of iterations, each of the reference voltages. A subsequent fine search operates, over a second succession of iterations, to individually adjust the reference voltages. Decoding and syndrome weight determination continues over each iteration until a minimum syndrome weight is obtained, after which a user data content of the code word is decoded. The coarse search may transition the decoder from a saturated operational region to a linear operational region. The decoder may be a low density parity check (LDPC) decoder.