ABSTRACT
Ternary Content-Addressable Memory (TCAM) is widely used in networking routers, fully associative caches, search engines, etc. While the conventional SRAM-based TCAM suffers from the poor scalability, the emerging nonvolatile memories (NVM, i.e., MRAM, PCM, and ReRAM) bring evolution for the TCAM design. It effectively reduces the cell size, and makes significant energy reduction and scalability improvement. New applications such as associative processors/accelerators are facilitated by the emergence of the nonvolatile TCAM (nvTCAM). However, nvTCAM design is challenging. In addition to the emerging device's uncertainty, the nvTCAM cell structure is so diverse that it results in a design space too large to explore manually. To tackle these challenges, we propose a circuit-level model and develop a simulation tool, NVSim-CAM, which helps researchers to make early design decisions, and to evaluate device/circuit innovations. The tool is validated by HSPICE simulations and data from fabricated chips. We also present a case study to illustrate how NVSim-CAM benefits the nvTCAM design. In the case study, we propose a novel 3D vertical ReRAM based TCAM cell, the 3DvTCAM. We project the advantages/disadvantages and explore the design space for the proposed cell with NVSim-CAM.
- [1].Predictive Technology Model. http://ptm.asu.edu/.Google Scholar
- [2]. . Ternary CAM power and delay model: extensions and uses. TVLSI, 16 (5):554–564, may 2008.Google Scholar
- [3]. Realization of vertical resistive memory (VRRAM) using cost effective 3D process. In IEDM, pages 31.8.1–31.8.4, dec 2011.Google Scholar
- [4]. . NV-TCAM: Alternative interests and practices in NVM designs. In NVMSA, pages 1–6, aug 2014.Google Scholar
- [5]. (10nm) 3D vertical ReRAM and NbO2 threshold selector with TiN electrode. In IEDM, pages 10.5.1–10.5.4, dec 2013.Google Scholar
- [6]. A 3T1R nonvolatile TCAM using MLC ReRAM with Sub-Ins search time. J SSC, 58: 318–319, feb 2015.Google Scholar
- [7]. PRIME: A novel processing-in-memory architecture for neural network computation in ReRAM-based main memory. In ISCA. volume 43, 2016.Google Scholar
- [8]. Design of high-performance CMOS priority encoders and incrementer/decrementers using multilevel lookahead and multilevel folding techniques. JSSC, 37 (1):63–76, 2002.Google Scholar
- [9]. AC-DIMM: associative computing with STT-MRAM. In ISCA, pages 189–200, 2013.Google Scholar
- [10]. 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. In VLSIC, pages 1–2, jun 2014.Google Scholar
- [11]. ACAM: Approximate computing based on adaptive associative memory with online learning. In ISLPED, 2016.Google Scholar
- [12]. Approximate computing using multiple-access single-charge associative memory. TETC, PP(99):1–1, 2016.Google Scholar
- [13]. Processing Acceleration with Resistive Memory-based Computation. In Memsys, 2016.Google Scholar
- [14]. ReMAM: low energy resistive multi-stage associative memory for energy efficient computing. In ISQED, pages 101–106, 2016.Google Scholar
- [15]. Resistive configurable associative memory for approximate computing. In DATE, pages 1327–1332, 2016.Google Scholar
- [16]. 1 Mb 0.41 um2 2T-2R cell nonvolatile team with two-bit encoding and clocked self-referenced sensing. JSSC, 49 (4):896–907. apr 2014.Google Scholar
- [17]. Leveraging nonvolatility for architecture design with emerging NVM. In NVMSA, pages 1–5, 2015.Google Scholar
- [18]. Pinatubo: a processing-in-memory architecture for bulk bitwise operations in emerging non-volatile memories. In DAC, page 173, 2016.Google Scholar
- [19]. A 256b-Wordlength ReRAM-based TCAM with Ins search-time and 14x improvement in wordlength-energyefficiency-density product using 2.5T1R cell. In ISSCC, pages 136–138, 2016.Google Scholar
- [20]. Nonvolatile processor architecture exploration for energy-harvesting applications. IEEE Micro, 35 (5):32–40, 2015.Google Scholar
Digital Library
- [21]. Fully parallel 6T-2MTJ nonvolatile TCAM with single-transistor-based self match-line discharge control. In VLSIC, pages 298–299, jun 2011.Google Scholar
- [22]. A 3.14 um2 4T-2MTJ-cell fully parallel TCAM based on nonvolatile logic-in-memory architecture. In VLSIC, pages 44–45, jun 2012.Google Scholar
- [23]. Implementation of a perpendicular MTJ-based read-disturb-tolerant 2T-2R nonvolatile TCAM based on a reversed current reading scheme. In ASP-DAC, pages 475–476, jan 2012.Google Scholar
- [24]. CACTI 6.0: A tool to model large caches. HP Lab., pages 22–31, 2009.Google Scholar
- [25]. Energy-efficient non-volatile TCAM search engine design using priority-decision in memory technology for DPI. In DA C, pages 1–6, june 2015.Google Scholar
- [26]. NVSim: A circuit-level performance, energy, and area model for emerging nonvolatile memory. TCAD, 31 (7):994–1007, jul 2012.Google Scholar
- [27]. Architecting 3D vertical resistive memory for next-generation storage systems. In ICCAD, pages 55–62, nov 2014.Google Scholar
- [28]. Modeling and design analysis of 3D vertical resistive memory: A low cost cross-point architecture. In ASP-DA C, pages 825–830, jan 2014.Google Scholar
- [29]. Memory and storage system design with nonvolatile memory technologies. IPSJ, 8: 2–11, 2015.Google Scholar
- [30]. Scaling 2-layer RRAM cross-point array towards 10 nm node: A device-circuit co-design. In ISCAS, pages 193–196, may 2015.Google Scholar
Comments