1T-SRAM

MoSys 1T-SRAM

1T-SRAM is a pseudo-static random-access memory (PSRAM) technology introduced by MoSys, Inc. in September 1998, which offers a high-density alternative to traditional static random-access memory (SRAM) in embedded memory applications. Mosys uses a single-transistor storage cell (bit cell) like dynamic random-access memory (DRAM), but surrounds the bit cell with control circuitry that makes the memory functionally equivalent to SRAM (the controller hides all DRAM-specific operations such as precharging and refresh). 1T-SRAM (and PSRAM in general) has a standard single-cycle SRAM interface and appears to the surrounding logic just as an SRAM would.

Due to its one-transistor bit cell, 1T-SRAM is smaller than conventional (six-transistor, or "6T") SRAM, and closer in size and density to embedded DRAM (eDRAM). At the same time, 1T-SRAM has performance comparable to SRAM at multi-megabit densities, uses less power than eDRAM and is manufactured in a standard CMOS logic process like conventional SRAM.

MoSys markets 1T-SRAM as physical IP for embedded (on-die) use in System-on-a-chip (SOC) applications. It is available on a variety of foundry processes, including Chartered, SMIC, TSMC, and UMC. Some engineers use the terms 1T-SRAM and "embedded DRAM" interchangeably, as some foundries provide MoSys's 1T-SRAM as "eDRAM". However, other foundries provide 1T-SRAM as a distinct offering.