Datasheet

PIC12F635/PIC16F636/639
DS41232D-page 42 © 2007 Microchip Technology Inc.
FIGURE 3-6: INTERNAL OSCILLATOR SWITCH TIMING
HFINTOSC
LFINTOSC
IRCF <2:0>
System Clock
HFINTOSC
LFINTOSC
IRCF <2:0>
System Clock
HF
LF
(1)
≠ 0 = 0
≠ 0 = 0
Start-up Time
2-cycle Sync Running
2-cycle Sync Running
HFINTOSC LFINTOSC (FSCM and WDT disabled)
Note 1: When going from LF to HF.
HFINTOSC LFINTOSC (Either FSCM or WDT enabled)
LFINTOSC
HFINTOSC
IRCF <2:0>
System Clock
= 0 ≠ 0
Start-up Time 2-cycle Sync
Running
LFINTOSC HFINTOSC
LFINTOSC turns off unless WDT or FSCM is enabled