27.2.4 FOSCSEL Configuration Register
Legend: PO = Program Once bit
| Name: | FOSCSEL |
| Offset: | 0xF18 |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| Access | |||||||||
| Reset |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| Access | |||||||||
| Reset |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| IESO | FNOSC[2:0] | ||||||||
| Access | R/PO | R/PO | R/PO | R/PO | |||||
| Reset | 1 | 1 | 1 | 1 | |||||
Bit 7 – IESO Internal External Switchover bit
| Value | Description |
|---|---|
1 |
Internal External Switchover mode is enabled (Two-Speed Start-up is enabled). |
0 |
Internal External Switchover mode is disabled (Two-Speed Start-up is disabled). |
Bits 2:0 – FNOSC[2:0] Initial Oscillator Source Selection bits
| Value | Description |
|---|---|
111 |
Internal Fast RC (FRC) Oscillator with Postscaler |
110 |
Backup Fast RC (BFRC) |
101 |
LPRC Oscillator |
100 |
Reserved |
011 |
Primary Oscillator with PLL (XTPLL, HSPLL, ECPLL) |
010 |
Primary (XT, HS, EC) Oscillator |
001 |
Internal Fast RC Oscillator with PLL (FRCPLL) |
000 |
Fast RC (FRC) Oscillator |