A nonvolatile look-up table using ReRAM for reconfigurable logic

Abstract

This study demonstrated a nonvolatile look-up table (nvLUT) that involves using resistive random access memory (ReRAM) cells with normally-off and instant-on functions for suppressing standby current. Compared with the conventional static random access memory (SRAM)-magnetoresistive random-access memory (MRAM)-hybrid LUTs the proposed ReRAM-based two-input nvLUT circuit decreases the number of transistors and the area of nvLUT by 79% and 90.4%, respectively. The areas of the two- and three-input ReRAM nvLUTs are 11.5% and 74.2% smaller than the other MRAM-based two-input and PCM-based three-input LUTs, respectively. Because of the low current switching and high R-ratio characteristics of ReRAM, the proposed ReRAM-based nvLUT achieves 24% less power consumption than that of SRAM-MRAM-hybrid LUTs. The functionality of the fabricated adder of the three-input ReRAM nvLUT was confirmed using an HfOx-based ReRAM and a 0.18-μm complementary metal-oxide semiconductor with a delay time of 900 ps.