An experimental 1-Mbit CMOS SRAM with configurable organization and operation

A 1-Mb SRAM (static random-access memory) configurable as a 128-kb*8, 256-kb*4, or 1-Mb*1 memory featuring asynchronous operation with static-column and chip-enable-access speedup modes or synchronous operation with a fast-page (toggle) or static-column mode is described. It has been fabricated in a double-metal, double-polysilicon CMOS process with 0.7- mu m geometry and special SRAM structures. The measured synchronous access of 29 ns with a fast-page mode access of 22 ns. Measured asynchronous access is 34 ns with a static-column access of 33 ns and a chip-select speedup access of 29 ns. The SRAMs six-transistor CMOS memory cell is 58.24 mu m/sup 2/.< >