RTC chip with 32,278 KHz X-tal.

A RTC or Real Time Clock is a build in time clock in electronic equipment such as an PC or an embedded processor. The RTC often has a battery power backup and the time are retained using a precision X-tal to minimize drift of time.

DS1307 RTC chip

A popular stand alone RTC chip is the DS1307 used by example by the popular Arduino^[1] embedded system.

In the picture to the right you can see a DS1307 chip driven by the 32,768 KHz X-tal. The reason for chosing 32768 Hz is that 2¹⁵ = 32768. The DS1307 contains a counter that repeatedly counts to 2¹⁵. Each time the counter reaches 32768 the time clock counts one second forward. Battery power backup is provided by the battery just visible in top right corner.

Beside the RTC the DS1307 contains 112 Bytes of RAM often used for configuration and password information. The time and contents of RAM are lost if the chip losses power.

Caetgory:RTC

↑ Arduino RTC time library using DS1307

[1] Arduino RTC time library using DS1307

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