27.3.2 Timer1 Mode for Compare

In Compare mode, Timer1 must be running in either Timer mode or Synchronized Counter mode. The compare operation may not work in Asynchronous Counter mode.

See the “TMR1 - Timer1 Module with Gate Control” chapter for more information on configuring Timer1.

Important: Clocking Timer1 from the system clock (F_OSC) must not be used in Compare mode. For Compare mode to recognize the trigger event on the CCPx pin, Timer1 must be clocked from the instruction clock (F_OSC/4) or from an external clock source.