What is the use of square wave off RTC?

Hi,
Anybody tell me what is the application of the programmable square waves generated by RTC IC's(DS1337 and many). I really dont know how to use. It may be a silly questions to many. But please clarify me.
regards,
Vamanan.

Hi Vamanan,

This output can be used for anything you need a 1Hz pulse for. I am using it to cause the LEDs to flash on alarm and it also syncronizes the beeping of the sonalert with the flashing. You can use it to feed an input on a micro and count how many seconds have elapsed. It could also be used to drive an LED that simply shows the clock chip is actually working. Keep in mind that if you change the 3rd bit in the control register to a "1", this output could be used as the 2nd alarm output. In order to use this output you will need to use a pullup resistor as it is an open-drain output.

If you don't already have one, you should download the manual on this great little chip. It's very important that you use the correct type of crystal with a 6pF load otherwise your clock time will not be very accurate over a period of time.

I wish I could find a user interface for it though. The program I use requires you to set the time a few minutes in advance, program the PIC, then start the clock. I have a "set clock" jumper on my boards for when I first start it up then remove the jumper and let a coin battery provide power backup in the event I shut the main board power off. I may have to just sit down and work on an interface for it.

Hope this helps you out!

BobK

Hi Vamanan.
"Use of SQURE WAVE OFF RTC".

All RTC can generate square wave signal in different frequency.With this Square wave we can lit LCD back light(like PWM).In my energy meter application i have to read ADC'sdata every one minitue it should be very precious.In this I used this Squarewave signal is to give one second external interrupt.I think It would be helpfull to you??!!