Datasheet

PIC16F631/677/685/687/689/690
DS40001262F-page 52  2005-2015 Microchip Technology Inc.
FIGURE 3-6: INTERNAL OSCILLATOR SWITCH TIMING
HFINTOSC
LFINTOSC
IRCF <2:0>
System Clock
HFINTOSC
LFINTOSC
IRCF <2:0>
System Clock
0 0
0 0
Start-up Time
2-cycle Sync Running
2-cycle Sync Running
HFINTOSC LFINTOSC (FSCM and WDT disabled)
HFINTOSC
LFINTOSC (Either FSCM or WDT enabled)
LFINTOSC
HFINTOSC
IRCF <2:0>
System Clock
= 0 ¼ 0
Start-up Time 2-cycle Sync
Running
LFINTOSC HFINTOSC
LFINTOSC turns off unless WDT or FSCM is enabled