The M62021 is a system IC that controls the memory backup function of SRAM and microcomputer (internal RAM). The IC outputs reset signals(RES/RES) to a microcomputer at power-down and power failure.It also shifts the power supply to RAM from main to backup,outputs a signal (CS) that invokes standby mode,and alters RAM to backup circuit mode. The M62021 contains,in a single chip,power supply monitor and RAM backup functions needed for a microcomputer system,so that the IC makes it possible to construct a system easily and with fewer components compared with a conventional case that uses individual ICs and discrete components.