An external clock source can be used as the device system clock by performing the following
actions:
- Program the RSTOSC Configuration
bits to select the external clock source (RSTOSC =
111
)
- Program the FEXTOSC Configuration
bits to select the appropriate External Clock (EC) mode:
- ECH mode for oscillators operating at or above 16 MHz (FEXTOSC =
11
)
- ECL mode for oscillator operating below 16 MHz (FEXTOSC =
01
)