RTC Full Form

RTC stands for Remote Time Clock. It is a computer-based clock formed over Integrated Circuits (IC) for keeping track of time. These clocks are different than Hardware clocks as hardware clocks don’t use time in human units. Today, almost every electronic device uses an RTC for keeping up with accurate time. In 1984, IBM introduced PC compatible RTC which used Motorola’s MC146818 RTC. Later, Dallas Semiconductors started mass production of compatible RTCs for old personal computers. Some microcontrollers had a built-in RTC while newer systems had them integrated with southbridge chips. Characteristics of RTC :

• Low Power Consumption – One of the important characteristics of an RTC is power consumption. Despite the main system powers down, RTCs continue to function properly. Against the absolute reference time set by the microprocessor, RTCs are capable of holding them.
• Commonly Used – Many electronic devices use an RTC for maintaining accurate time. They are easily integrated with other devices like Automotive applications.
• No Clock Signals – An RTC does not rely on clock signals of a hardware clock as it uses a crystal oscillator. Therefore, RTC displays time accurately without any errors.
• Alarm Functions – RTCs can also have alarm functions that could trigger for a specific task.
• Switching – When the system is working fine, RTCs draw power from digital circuits. But in the case of power down, they switch to a continuous power source.
• Life Span – An RTC’s battery can last at least three years or more. Therefore, RTCs have a longer lifetime than other devices.

Advantages :

• An RTC ensures the synchronization of processes that occur within the system as the system clock indirectly dependent on it.
• It doesn’t let any Time Critical Task (Any critical task bounded by time constraints) affect the functionality of the main system.
• It is more accurate and effective for maintaining time than other programs and devices.
• RTCs are more efficient as it consumes less power in comparison to other devices. 4

Disadvantage :

• An RTC needs a continuous power supply to keep itself running.