Two-13 ns-64K CMOS SRAM´s with very low active power and improved asynchronous circuit techniques

64K×1 and 16K×4 CMOS SRAMs which achieve an access time of 13 ns and less than 12-mA active current at 10 MHz are described. A double-metal 1.5-μm p-well process is used. A chip architecture with local amplification improves signal speed and data integrity. Address stability detection techniques are introduced as a method of assuring full asynchronicity over a wide range of conditions. A chip-select speed-up circuit allows high-speed access from a power-down mode. A memory cell design is presented which has improved layout efficiency (area of 189 μm/SUP 2/), yet provides a very high cell ratio of 3:1 for signal stability and margin. Experimental results are presented which demonstrate full performance under address skews and other asynchronous input conditions. High-speed enable access and address access are observed over a wide range of operating conditions.