Energy-scalable 4KB LDPC decoding architecture for NAND-flash-based storage systems

Abstract

This paper presents a novel low-power decoder architecture for the (36420, 32778) binary LDPC code targeting energy-efficient NAND-flash-based mobile devices. The proposed energy-scalable decoding algorithm reduces the operating bit-width of decoding function units at the early-use stage where the channel condition is good enough to lower the precision of computation. Based on a flexible adder structure, the decoding energy of the proposed LDPC decoder can be reduced by freezing the unnecessary parts of hardware resources. A prototype 4KB LDPC decoder is designed in a 65nm CMOS technology, which achieves an average decoding throughput of 8.13Gb/s with 1.2M equivalent gates. The power consumption of the decoder ranges from 397mW to 563mW depending on operating conditions.