標題: | A 0.325 V, 600-kHz, 40-nm 72-kb 9T Subthreshold SRAM with Aligned Boosted Write Wordline and Negative Write Bitline Write-Assist |
作者: | Lu, Chien-Yu Chuang, Ching-Te Jou, Shyh-Jye Tu, Ming-Hsien Wu, Ya-Ping Huang, Chung-Ping Kan, Paul-Sen Huang, Huan-Shun Lee, Kuen-Di Kao, Yung-Shin 電子工程學系及電子研究所 Department of Electronics Engineering and Institute of Electronics |
關鍵字: | 9T static random access memory (SRAM);boosted wordline;line-up write-assist (LUWA);negative bitline;subthreshold;ultralow voltage |
公開日期: | 1-五月-2015 |
摘要: | This brief presents a two-port disturb-free 9T subthreshold static random access memory (SRAM) cell with independent single-ended read bitline and write bitline (WBL) and cross-point data-aware write structure to facilitate robust subthreshold operation and bit-interleaving architecture for enhanced soft error immunity. The design employs a variation-tolerant line-up write-assist scheme where the timing of area-efficient boosted write wordline and negative WBL are aligned and triggered/initiated by the same low-going global WBL to maximize the write-ability enhancement. A 72-kb test chip is implemented in United Microelectronics Corp. 40-nm low-power (40LP) CMOS. Full functionality is achieved for V-DD ranging from 1.5 to 0.32 V without redundancy. The measured maximum operation frequency is 260 MHz (450 kHz) at 1.1 V (0.32 V) and 25 degrees C. At 0.325 V and 25 degrees C, the chip operates at 600 kHz with 5.78 mu W total power and 4.69 mu W leakage power, offering 2x frequency improvement compared with 300 kHz of our previous 72-kb 9T subthreshold SRAM design in the same 40LP technology. The energy efficiency (power/frequency/IO) at 0.325 V and 25 degrees C is 0.267 pJ/bit, a 23.7% improvement over the 0.350 pJ/bit of our previous design. |
URI: | http://dx.doi.org/10.1109/TVLSI.2014.2318518 http://hdl.handle.net/11536/124832 |
ISSN: | 1063-8210 |
DOI: | 10.1109/TVLSI.2014.2318518 |
期刊: | IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS |
Volume: | 23 |
起始頁: | 958 |
結束頁: | 962 |
顯示於類別: | 期刊論文 |