嵌入式SRAM优化设计

【作者】 王磊；

【导师】 贾宇明；

【作者基本信息】 电子科技大学 ， 材料学， 2003， 硕士

【摘要】 本文设计了512×8 SRAM（静态随机读写存储器），设计基于UMC 0.35工艺，地址取数时间小于6ns。由于所设计的SRAM作为嵌入式IP模块应用，因此在速度、面积、功耗三者之间反复权衡，力求达到一个最佳值。设计中采用了诸如存储阵列分块技术，地址探测技术，预充电及平衡技术，分段译码技术，分级敏感放大器等一些新技术。电路包括存储阵列、译码电路、敏感放大器、数据输入输出电路，预充电电路等部分。着重于介绍如何降低存储器的功耗和提高存储器的速度。噪声容限的优化增强了SRAM的抗干扰能力。存储阵列分块技术以及分段译码技术降低了SRAM位线和字线的负载电容，从而提高了SRAM的速度。地址探测技术的采用保证SRAM的异步应用。两级敏感放大器的应用在确保对位线微小电压差的放大的条件下，提高了抗干扰能力。设计用Hspice、Star_sim、以及Star_simXT进行仿真，并对不同仿真条件下的仿真结果进行了描述。针对SRAM作为嵌入式应用时测试难的问题，设计了BIST(内建自测试)和BISR（内建自修复）电路，分析了SRAM常见的故障，并描述了针对这些常见故障所采用的算法，采用了故障覆盖面较大的March C+算法设计了BIST电路。对于BISR电路的设计本文提出了两种方案，对两者的优缺点做了比较后作出选择。更多还原

【Abstract】 An optimized design of embedded 512×8 SRAM which bases on UMC 0.35 μm technics for speed-raising and power-dissipation-saving is presented. It’s address access time less than 6ns. Because of being used as embedded IP, the SRAM is optimized on speed, area, and power dissipation. Some new technologies such as dividing the memory array into separated sub-arrays, ATD, pre-charge and balance, subsection decoding, multilevel sense amplifier, etc have been used. The whole circuit includes memory array, decode, sense amplifier, data in-out circuit and pre-charge circuit. The emphasis is put on how to depress the power dissipation of the memory and how to improve its speed. The optimization of cell static noise margin enhances the anti-jamming ability of SRAM. Sub-array and subsection decoding reduce the load capacitance of bit line and word line and enhance the speed of SRAM simultaneously. ATD made the asynchronous use of SRAM. Two-level sense amplifier amplifies the tiny voltage difference between the bit lines and enhances the anti-jamming ability. The design is simulated by Hspice, Star_sim and Star_simXT under different condition and the results are given. The DFT to SRAM is discussed and BIST and BISR circuit are designed. After analyzing the normal faults of SRAM, the Algorithms of memory BIST are discussed and the March C+ is selected. Two designs of BISR circuit are put and after comparing, one of them is selected.更多还原