SRAM

SRAM, or static random-access memory, is a type of semiconductor memory that uses bistable latching circuitry to store each bit. Each bit is held by a flip-flop composed of multiple transistors, typically a 6-transistor (6T) memory cell. Unlike dynamic RAM (DRAM), SRAM does not require periodic refreshing to retain data as long as power is supplied. This makes SRAM fast and reliable for short-term storage, though it is more complex and costly to produce per bit.

SRAM memory is organized as arrays of cells with row and column decoders, sense amplifiers, and write/read circuitry. Access to a cell is controlled by word lines and bit lines. Variants include asynchronous SRAM, which responds immediately to input changes, and synchronous SRAM, which operates on clocked timing suitable for high-speed systems. Modern designs also use alternative cell architectures, such as 8T or other multi-transistor cells, to improve stability and reduce read disturbances.

Key advantages of SRAM are its high speed, low latency, and simple control logic, which make it ideal for cache memory and other on-chip storage where speed and predictability are critical. The main disadvantages are lower density and higher cost per bit, as well as greater silicon area and, in some cases, higher static power consumption compared with DRAM. These factors limit SRAM’s use to smaller capacities, such as CPU caches (L1, L2, L3) and other fast buffers.

Overall, SRAM remains essential in high-performance computing environments where fast, deterministic access to memory is required, while DRAM and flash memory handle larger, cost-driven storage needs.