hi,for the PIC16F84, if i need to reset and clear all
how will the coding in MikroC look like?

 

I think that would be a goto to the reset vector adress 0x0000h.
Edit: In order to have full reset you must use the reset pin. But depending on how you write your software a goto to 0x0000 may be very close to a full reset

 

if i have a reset button on reset pin MCLR
i just need to press the button and will be full reset?
no code is need for reset?

 

Wire one of your pins to MCLR, and pull it low. Remember to normally pull it high with a weak 1k resistor. That should do the job. I know the higher end PIC chips have an actual RESET instruction which resets all file registers to their default state, unfortunately yours is not one of them.

 

Yes that is correct. Pulling the MCLR pin low, will rest the CPU. No code needed. A common circuit is this one.

If you use a ICSP please refer to fFIGURE 3-1: TYPICAL ICSP. APPLICATION CIRCUIT in this document http://ww1.microchip.com/downloads/en/DeviceDoc/51553E.pdf