abbas.khodaeian, I am sorry but you cannot reach an acceptable boudrate of 115200 with 16F series even with a 20 Mhz oscillator.

If you want to use the 16F84a, then you must change the phone type and use a brand with boudrate @ 9600 (siemens for instance. make sure they work in text mode)


i don't need the high frequency for processing, but i need high baud rate to communicate with the nokia 3310
The high frequency clock and the pic 18F are necessary to reach the high boudrate required by your nokia 3310.

Al.