Hello Shankar,

I always use a Philips PCF8583 RTC.

- This RTC comes in a DIL8 package
- Is has some RAM
- It is connected via I2C to your microcontroller
- It has an external 32 kHz crystal-oscillator
- You have to supply it with a battery backup voltage
- You should use a Reset Controller for your microcontroller

If you are interested, mail me.

Ciao, Michael