Bulkyflip: A NAND-SPIN-Based Last-Level Cache With Bandwidth-Oriented Write Management Policy
Autor: | Ying Wang, Pengcheng Dai, Weisheng Zhao, Youguang Zhang, Chao Wang, Jianlei Yang, Yuanqing Cheng, Bi Wu, Dijun Liu, Zhaohao Wang, Xiaobo Sharon Hu |
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Rok vydání: | 2020 |
Předmět: |
Hardware_MEMORYSTRUCTURES
business.industry Computer science 020208 electrical & electronic engineering Bandwidth (signal processing) NAND gate Supply current High capacity 02 engineering and technology CMOS Embedded system 0202 electrical engineering electronic engineering information engineering Cache Static random-access memory Electrical and Electronic Engineering business Dram |
Zdroj: | IEEE Transactions on Circuits and Systems I: Regular Papers. 67:108-120 |
ISSN: | 1558-0806 1549-8328 |
Popis: | High capacity last-level caches (LLCs) are being used to help alleviate the growing speed gap between the processor and main memory. However, traditional CMOS based memory technologies (SRAM, DRAM, et al.) for such LLCs consume high static power. Non-volatile memory such as STT-MRAM has been proposed as a low power solution for LLCs. Nevertheless, the high write current induces a so-called “supply current threshold” issue and limits the maximum number of bit-cells that can be written concurrently in one cycle in an STT-MRAM cache. This drawback significantly decreases the bandwidth of the STT-MRAM cache compared with SRAM. In this work, we present a hardware implementation of NAND-like spintronic memory (NAND-SPIN) LLC for the first time. By exploiting the unique erase-then-program operation for writing NAND-SPIN, we propose an adaptive buffer entry (ABE) write policy for each cache write access. Instead of writing a fixed number of bits sequentially, our method adaptively extends the write data length under a fixed maximum cache supply current. Compared to existing STT-MRAM caches, ‘ABE’ can achieve 70% performance improvements on average. Compared with the conventional early write terminate (EWT) policy, ‘ABE’ can save 33% write energy on average with negligible hardware overhead. |
Databáze: | OpenAIRE |
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