2.4 External Clock Operation

The timer can operate from an external aperiodic clock by setting CSYNC = 0. Refer to Synchronous vs. Asynchronous Operation for more information about clock synchronization. Note that with CSYNC = 1, clock synchronization delays will apply, which is unreliable since the input signal is aperiodic and may not be toggling. With CSYNC = 0, the effect of the gate is immediate, without synchronization delays. For reliable operation the user must ensure that the inputs meet reasonable setup and hold times of a few nanoseconds. The following use case demonstrates this.