10.9 Oscillator Configuration
The oscillator system has both Configuration registers and SFRs to configure, control and monitor the system. The FOSCSEL and FOSC Configuration registers (FOSCSEL and FOSC, respectively) are used for initial setup.
Table 10-1 lists the configuration settings that select the device’s oscillator source and operating mode at a Power-on Reset (POR).
| Oscillator Source | Oscillator Mode | FNOSC[2:0] Value | POSCMD[1:0] Value | Notes |
|---|---|---|---|---|
| S0 | Fast RC Oscillator (FRC) | 000 | xx | Note 1 |
| S1 | Fast RC Oscillator with PLL (FRCPLL) | 001 | xx | Note 1 |
| S2 | Primary Oscillator (EC) | 010 | 00 | Note 1 |
| S2 | Primary Oscillator (XT) | 010 | 01 | |
| S2 | Primary Oscillator (HS) | 010 | 10 | |
| S3 | Primary Oscillator with PLL (ECPLL) | 011 | 00 | Note 1 |
| S3 | Primary Oscillator with PLL (XTPLL) | 011 | 01 | |
| S3 | Primary Oscillator with PLL (HSPLL) | 011 | 10 | |
| S4 | Reserved | 100 | xx | |
| S5 | Low-Power RC Oscillator (LPRC) | 101 | xx | Note 1 |
| S6 | Backup FRC (BFRC) | 110 | xx | Note 1 |
| S7 | Fast RC Oscillator with ÷ N Divider (FRCDIVN) | 111 | xx | Note 1, Note 2 |
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Note:
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