Dear Andy,
First of all thankyou very much for your comments.
I need all these three sources. Otherwise, It won't be possible to sense clock/timer alarm, or get current/voltage/waveform data from ADE7753 or set the graphic LCD or timer/clock by push-buttons. One of the better solution is (as you recomended) combining ADE and PCF interrupts on INT0 input. And when an INT0 interrupt occurs, ISR must control which source is requesting. But, later on, I realised that, priority setting will not be controlled. I mean, when ADE interrupt service soutine is being executed, PCF inturrupt (timer or clock alarm) will not be able to sense. I don't know whether an external hardware usage will be the best solution (if it will what kind of IC/hardware must be used?) or not. Is there any other solution without using any additional hardware that you can suggest?
Again thankyou very much for your suggestion dear Andy.

Please let me know is there any other way to pass the problem please,
Best Regards,
Batu