All Compare modes can generate an interrupt (except the Special Event Mode). However, when the Generate Software Interrupt mode is chosen (CCPxM<3:0> = 1010), the CCPx module does not assert control of the CCPx pin.
To generate an interrupt the Global Interrupt Enable (GIE) bit and the CCPxIE bit in the corresponding Peripheral Interrupt Register must both be set. For more detail on the interrupt structure refer to the Interrupts Training Module.
Microchip Technology acquires Atmel