PIC16F639 Microchip Technology Inc., PIC16F639 Datasheet - Page 46

• Manufacturer Part Number: PIC16F639
• Description: 8/14-pin Flash-based, 8-bit Cmos Microcontrollers With Nanowatt Technology
• Manufacturer: Microchip Technology Inc.

PIC12F635/PIC16F636/639
3.7.3
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:
DS41232D-page 44
Program Counter
System Clock
HFINTOSC
CHECKING TWO-SPEED CLOCK
STATUS
OSC1
OSC2
TWO-SPEED START-UP
0
PC - N
1
T
T
OST
1022 1023
PC
PC + 1
© 2007 Microchip Technology Inc.