A Twin-8T SRAM Computation-in-Memory Unit-Macro for Multibit CNN-Based AI Edge Processors
Autor: | Wei-Hsing Huang, Ren-Shuo Liu, Yung-Ning Tu, Shimeng Yu, Yen-Cheng Chiu, Meng-Fan Chang, Qiang Li, Xiaoyu Sun, Jia-Jing Chen, Jing-Hong Wang, Rui Liu, Chih-Cheng Hsieh, Kea-Tiong Tang, Wei-Chen Wei, Xin Si, Ssu-Yen Wu |
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Rok vydání: | 2020 |
Předmět: | |
Zdroj: | IEEE Journal of Solid-State Circuits. 55:189-202 |
ISSN: | 1558-173X 0018-9200 |
Popis: | Computation-in-memory (CIM) is a promising candidate to improve the energy efficiency of multiply-and-accumulate (MAC) operations of artificial intelligence (AI) chips. This work presents an static random access memory (SRAM) CIM unit-macro using: 1) compact-rule compatible twin-8T (T8T) cells for weighted CIM MAC operations to reduce area overhead and vulnerability to process variation; 2) an even–odd dual-channel (EODC) input mapping scheme to extend input bandwidth; 3) a two’s complement weight mapping (C2WM) scheme to enable MAC operations using positive and negative weights within a cell array in order to reduce area overhead and computational latency; and 4) a configurable global–local reference voltage generation (CGLRVG) scheme for kernels of various sizes and bit precision. A 64 $\times $ 60 b T8T unit-macro with 1-, 2-, 4-b inputs, 1-, 2-, 5-b weights, and up to 7-b MAC-value (MACV) outputs was fabricated as a test chip using a foundry 55-nm process. The proposed SRAM-CIM unit-macro achieved access times of 5 ns and energy efficiency of 37.5–45.36 TOPS/W under 5-b MACV output. |
Databáze: | OpenAIRE |
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