Function of CMOS in Computer

Function of CMOS:

CMOS is a type of memory that requires very little power (about one-millionth of an amp) to retain any data stored on it. It stands for Complementary Metal-Oxide Semiconductor. It can store a PC’s configuration data for many years with power from low voltage dry cell or lithium batteries. The main function of CMOS is to provide power supply to the CMOS chip when the computer is shut down.

CMOS is the technology used to manufacture the transistors used in memory and IC chips. The BIOS CMOS memory stores the system configuration. It includes any modifications made to the system, its hard drives, peripheral settings, or other settings. The system and RTC (real-time clock) settings also stored in the CMOS.

The information on the computer’s hardware stored in the computer’s CMOS memory. Originally, CMOS technology used only for storing the system setup information. When the computer started up, the CMOS data read and used as a checklist to verify that the devices indicated present and operating. Once the hardware check completed, the BIOS loads the operating system and passes control of the computer to it. From that point on, the BIOS is available to accept requests from device drivers and application programs for hardware assistance.

CMOS Working Principle:

CMOS Working Principle In CMOS technology, both N-type and P-type transistors used to design logic functions. The same signal which turns ON a transistor of one type used to turn OFF a transistor of the other type.

This characteristic allows the design of logic devices using only simple switches, without the need for a pull-up resistor. In CMOS logic gates a collection of n-type MOSFETs arranged in a pull-down network between the output and the low voltage power supply rail (Vss). Instead of the load resistor of NMOS logic gates, CMOS logic gates have a collection of p-type MOSFETs in a pull-up network between the output and the higher-voltage rail (Vdd).