PIC16F631_08 Datasheet, PDF (58/306 Pages) Microchip Technology – 20-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F631/677/685/687/689/690
3.7.3
CHECKING TWO-SPEED CLOCK
STATUS
Checking the state of the OSTS bit of the OSCCON
register will confirm if the microcontroller is running
from the external clock source, as defined by the
FOSC<2:0> bits in the Configuration Word register
(CONFIG), or the internal oscillator.
FIGURE 3-7:
TWO-SPEED START-UP
HFINTOSC
TOST
OSC1 0 1 1022 1023
OSC2
Program Counter PC - N
PC
System Clock
PC + 1
DS41262E-page 56
© 2008 Microchip Technology Inc.