Skhynix Inc.

Korea Advanced Institute of Science and Technology

Ji Eun Oh

Jeong Seok Ha

Dae-Sung Kim

Myung In Kim

A method for operating a Low Density Parity Check (LDPC) decoder includes assigning each symbol of a codeword as a variable node value for each of a plurality of variable nodes, performing syndrome checking on each check node based on a parity check matrix, calculating flipping function values of the variable nodes based on syndrome values of check nodes and a flipping function, dividing the flipping function values into a plurality of groups, determining a flipping function threshold value based on a group maximum value of a group among the groups, and selectively flipping a variable node value based on a comparison result of a flipping function value of corresponding variable node and the determined flipping function threshold value.

LDPC decoder, operating method of LDPC decoder, and semiconductor memory system

A decoding method for a low density parity check (LDPC) code includes: updating a first check node, among a plurality of check nodes, by receiving, by the first check node, a bit decision and an associated first reliability value from each of a subset of variable nodes including a first variable node among a plurality of variable nodes, calculating a syndrome value and a second reliability value of the first check node based on the received bit decisions and first reliability values, and outputting the calculated syndrome value and second reliability value of the first check node to a variable node of the plurality of variable nodes but not of the subset of variable nodes; and updating the first variable node by receiving, by the first variable node, a syndrome value and a second reliability value of a second check node among the plurality of check nodes, and updating the first reliability value of the first variable node based on the syndrome value and the second reliability value of the second check node.

Growing community of inventors

Daejeon, South Korea

Ji Eun Oh