@techreport{oai:ipsj.ixsq.nii.ac.jp:00026797, author = {奥村, 俊介 and 藤原, 英弘 and 井口, 友輔 and 野口, 紘希 and 森田, 泰弘 and 川口, 博 and 吉本, 雅彦 and Shunsuke, Okumura and Hidehiro, Fujiwara and Yusuke, Iguchi and Hiroki, Noguchi and Yasuhiro, Morita and Hiroshi, Kawaguchi and Masahiko, Yoshimoto}, issue = {38(2008-SLDM-135)}, month = {May}, note = {信頼性を動的に変化させることが可能なディペンダブル SRAM を提案する.提案する SRAM は 7 トランジスタ(7T)構成であり,2つの従来 6T メモリセルを1組として,双方の内部ノードを追加トランジスタで接続する.提案 SRAM は通常モード,高速アクセスモード,そして高信頼性モードの3種類のモードを有する.提案 SRAM の高速アクセスモードでは,従来の 6T SRAM と比較して読出しセル電流が 142%増加し,その結果読出し時のビット線放電時間は 66.3%短縮される.また,高信頼性モードにおいては,Bit error rate(BER)が 2.5x10-2 改善された.面積オーバーヘッドは追加トランジスタに PMOS を用いた場合は 12%である., We propose a novel dependable SRAM with 7T memory cell pair, and introduce a new concept, “quality of a bit (QoB)” for it. The proposed SRAM has three modes: a typical mode, high-speed mode, and dependable mode, in which the QoB is scalable. That is, the area, speed, reliability, and/or power of one-bit information can be controlled. In the typical mode, assignment of information is as usual as one memory cell has one bit. On the other hand, in the high-speed or dependable mode, one-bit information is stored in two memory cells, which boosts the speed or increases the reliability. In the high speed mode, the cell current is increased by 142%, and bitline discharge time is reduced by 66.3%. Furthermore, in dependable mode, Bit error rate (BER) in proposed SRAM is improved by 2.5x10-2. Compared with the conventional 6T memory cell, the respective area overheads are 30% and 12%, in the nMOS and pMOS additional cases.}, title = {高信頼性モードと高速アクセスモードを有するディペンダブル SRAM}, year = {2008} }