ReRAM-based 4T2R nonvolatile TCAM with 7x NVM-stress reduction, and 4x improvement in speed-wordlength-capacity for normally-off instant-on filter-based search engines used in big-data processing

Abstract

This study proposes an RC-filtered stress-decoupled (RCSD) 4T2R nonvolatile TCAM (nvTCAM) to 1) suppress match-line (ML) leakage current from match cells (IML-M), 2) reduce ML parasitic load (CML), 3) decouple NVM-stress from wordlength (WDL) and IML-MIS. RCSD reduces NVM-stress by 7+x, and achieves a 4+x improvement in speed-WDL-capacity-product. A 128×32b RCSD nvTCAM macro was fabricated using HfO ReRAM and an 180nm CMOS. This paper presents the first ReRAM-based nvTCAM featuring the shortest (1.2ns) search delay (TSD) among nvTCAMs with WDL≥32b.