11.2 Clock Source Types
Clock sources can be classified as external or internal.
- Digital oscillator modules
Internal clock sources are contained within the oscillator module. The internal oscillator block features two internal oscillators that are used to generate internal system clock sources. The High-Frequency Internal Oscillator (HFINTOSC) can produce a wide range of frequencies which are determined via the HFINTOSC Frequency Selection (OSCFRQ) register. The Low-Frequency Internal Oscillator (LFINTOSC) generates a fixed nominal 31 kHz clock signal. The internal oscillator block also features an RC oscillator (ADCRC) which is dedicated to the Analog-to-Digital Converter (ADC).
The instruction clock (FOSC/4) can be routed to the CLKOUT pin
when the pin is not in use. The Clock Out Enable (CLKOUTEN)
Configuration bit controls the functionality of the CLKOUT signal. When
CLKOUTEN is clear (CLKOUTEN =
0
), the CLKOUT signal is routed to the CLKOUT pin. When
CLKOUTEN is set (CLKOUTEN =
1
), the CLKOUT pin functions as an I/O pin.