The CMOS (complementary metal-oxide semiconductor) provides power to a motherboard in order to track the time while a computer is powered off. If the CMOS battery dies or malfunctions the PC will not be able to track the system time.
Nonvolatile BIOS memory refers to a small memory on PC motherboards that is used to store BIOS settings. It is traditionally called CMOS RAM because it uses a volatile, low-power complementary metal-oxide-semiconductor (CMOS) SRAM (such as the Motorola MC146818 or similar) powered by a small "CMOS" battery when system and standby power is off. The typical NVRAM capacity is 256 bytes.
The CMOS RAM and the real-time clock have been integrated as a part of the …