Asynchronous SRAM

Asynchronous SRAM
  Asynchronous SRAM(Asynchronous Static Random Access Memory) is a type of semiconductor memory that uses bistable latching circuitry (flip-flop) to store each bit.Asynchronous SRAM exhibits data remanence,but it is still volatile in the conventional sense that data is eventually lost when the memory is not powered.
    The term static differentiates Asynchronous SRAM from DRAM (Dynamic Random Access Memory) which must be periodically refreshed.Asynchronous SRAM is faster and more expensive than DRAM; it is typically used for CPU cache while DRAM is used for a computer's main memory.