Synchronous dynamic random access memory (SDRAM) is dynamic random access memory (DRAM) that is synchronized with the system bus. SDRAM has a synchronous interface; it waits for a clock signal before responding to control inputs and is therefore synchronized with the computer's system bus. SDRAM is volatile and very fast technology. Four generations are today used in electronic circuits (SDR SDRAM, DDR2 SDRAM, DDR3 SDRAM et DDR4 SDRAM).

 

fig1 : SDRAM device