2.2 Timer1 Mode for Capture

Timer1 must be operating synchronously to the system clock for the CCP module to use the capture feature. When Timer1 uses the internal instruction clock (FOSC/4) as its clock source, clock synchronization is handled by module hardware automatically. When Timer1 uses an external clock source, the Timer External Clock Input Synchronization Control (SYNC) bit must be clear (SYNC = 0) so that the external source is synchronized with the system clock. If the Timer clock source is not synchronized, the capture operation may not work.

See the “TMR1 - Timer1 Module with Gate Control” chapter in the device data sheet for more information on configuring Timer1 for use with the CCP module.

Important: Do not clock Timer1 from the system clock (FOSC) in Capture mode. In order for Capture mode to recognize the trigger event, Timer1 must be clocked from the instruction clock or from an external clock source.