Static SRAM does not need to be refreshed, the speed can be very fast, for example, the CPU internal cache, are static RAM, the disadvantage is that the memory cell requires a large number of transistors, so expensive, small capacity. static SRAM random access memory power-up, no need to refresh, data will not be lost, generally not row address multiplexing.
SRAM it is a semiconductor memory. Static means that the data stored in the middle of SRAM will not be lost as long as the power is not dropped. This is different from DRAM, which requires periodic refresh operations.
We should not confuse SRAM with ROM and Flash Memory, because SRAM it is a memory that is prone to loss and can only hold data when power is continuously supplied. Random access means that the contents of the memory can be accessed in any order, regardless of the previously accessed location.
SRAM is stored in four transistors each, forming two cross-coupled inverters. The memory cell has two stable states, usually 0 and 1. In addition two access transistors are required to control access to the memory cell during reading or writing. Therefore the memory bits usually require six MOSFETs. making the circuit structure symmetrical SRAM accesses faster than DRAM.
Another reason why SRAM is faster than DRAM access is that SRAM can receive all address locations at once, and DRAM uses a row address and column address multiplexing structure.
SRAM should not be confused with SDRAM, which stands for Synchronous DRAM, which is completely different from SRAM.
SRAM should not be confused with PSRAM either. pSRAM is a DRAM disguised as SRAM.
