An interrupt requires immediate attention, only once the microcontroller will finish executing the interrupt code, then it can go back to continue with the main program. The interrupt code is called Interrupt Service Routine (ISR) or Interrupt Handler. In this article we're gonna learn how to implement Interrupts using MikroC Pro for PIC compiler. The individual bits of the 8-bit GPIO port can be configured as input or output. The port pins can also be enabled for internal pull up resistor and interrupt-on-change. These operations are controlled through a set of configuration and control registers. The table below shows the list of these registers, their addresses and the power-on reset ... Interrupt upon a change on pins 4, 5, 6 and 7 of port B Change of input signal on PORTB <7:4> sets RBIF (INTCON<0>) bit. Four pins RB7, RB6, RB5 and RB4 of port B, can trigger an interrupt which occurs when status on them changes from logic one to logic zero, or vice versa.