It is possible. First, take this in mind: the PIC16F877A works with 5V, and the phone works at 3 or 3.3V; so, we need to convert 5V to 3 or 3.3V interface.
For that, just use a voltage divider with a couple of resistors you find easily at your residence zone, you could protect the 3 or 3.3V side with a 3.3 V Zener in addition to the voltage divider...