Differences and uses of SRAM, DRAM, SDRAM and DDR

sram

Static Random-Access Memory Static random access memory . Data loss after power failure , There is no need to power on periodically . After power on , The data will not be affected until the power is off . Commonly used in cpu Second level cache . Because the price is high , So it cannot be used as memory .

dram

Dynamic Random Access Memory Dynamic RAM , Data loss after power failure , Need periodic power on .

sdram

Synchronous Dynamic Random Access Memory, Synchronous dynamic random access memory , Synchronization means Memory Work needs to synchronize the clock .

ddr

Double Data Rate Double rate synchronous dynamic random access memory , Strictly speaking DDR It should be called DDR SDRAM. therefore ,SDRAM It has been adopted since the second generation DDR technology , In a nutshell DDR Memory is SDRAM A kind of