Basic principle of memory SRAM

First,the basic principle of memory SRAM

The basic memory cell of SRAM is composed of six transistors,which jointly store 1 bit of data.The cell contains three important signal lines:two data lines(BL and BLB)are used to transmit reading and writing information,and one word line(WL)controls the access rights to the cell.The cell represents"1"and"0"through power supply and grounding respectively.As long as the power supply is continuous,the data can be kept stably,and there is no need to refresh periodically like DRAM.
 

Second,the read-write mechanism of SRAM

Multiple memory cells of SRAM will be arranged in a matrix structure.The external address signal passes through the decoding circuit,and a group of cells specified in the matrix can be selected.Unlike DRAM,which needs row and column addresses,SRAM has more direct addressing and more flexible design-one address can correspond to different bit widths such as 8,32 and 64 bits.
 

After selecting the storage unit,the operation type needs to be determined by reading and writing control signals.When writing,external data is sent to the storage unit through the driving circuit;When reading,the data in the cell is driven to the external data line.In addition,SRAM usually has a chip select signal to enable or disable the read-write function of the chip.
 

Third,the advantages and limitations of SRAM

The most obvious advantage of SRAM is its high speed,because it does not need refresh operation and its access delay is extremely low.However,this performance of SRAM comes at the cost of high hardware cost:one bit needs six transistors,which leads to a larger chip area,lower integration and higher manufacturing cost.At the same time,more transistors also mean higher power consumption.
 

Fourth,the core application of SRAM:CPU cache

Because of its high speed,SRAM is widely used to build the internal cache of CPU.In modern processors,cache often occupies half or more of the chip area,and the running frequency is close to the main frequency of CPU,so the power consumption is considerable.Despite the high cost,SRAM is still an indispensable choice for greatly improving data processing efficiency.