The oscillator module contains multiple clock sources and selection features that allow it to be used in a wide range of applications while maximizing performance and minimizing power consumption.
The Reset Oscillator (RSTOSC) Configuration bits determine the type of oscillator that will be used when the device runs after a Reset, including when the device is first powered up (see the table below).
RSTOSC | SFR Reset Values | Clock Source | |
---|---|---|---|
COSC | OSCFRQ | ||
11 |
11 |
000 |
EXTOSC per FEXTOSC |
10 |
10 |
HFINTOSC @ 1 MHz | |
01 |
01 |
LFINTOSC | |
00 |
00 |
101 |
HFINTOSC @ 32 MHz |
The ECH and ECL modes rely on an external logic-level signal as the device clock source. Each mode is optimized for a specific frequency range. The internal oscillator block produces both low-frequency and high-frequency clock signals, designated LFINTOSC and HFINTOSC, respectively. Multiple system operating frequencies may be derived from these clock sources.
Figure 1 illustrates a block diagram of the oscillator module.