LDPC LDPC LDPC DECODER OPERATING METHOD OF LDPC DECODER AND SEMICONDUCTOR MEMORY SYSTEM

摘要

A method of operating a low density parity check (LDPC) decoder includes: allocating each of the symbols of a codeword as a variable node value of each of a plurality of variable nodes; performing a syndrome check of each check node based on the parity check matrix; calculating inversion function values of each of the plurality of variable nodes based on the syndrome values of the check node and the inversion function; dividing the plurality of inversion function values into a plurality of groups; determining an inversion function threshold value based on a group maximum value of any one group in the plurality of groups; and selectively inverting the variable node value according to the comparison result of the inversion function value and the inversion function threshold value.