Microchip Technology MA240017 Data Sheet

Page of 278
 2008-2011 Microchip Technology Inc.
DS39927C-page 91
PIC24F16KA102 FAMILY
9.0
OSCILLATOR 
CONFIGURATION
The oscillator system for the PIC24F16KA102 family of
devices has the following features:
• A total of five external and internal oscillator options 
as clock sources, providing 11 different clock 
modes.
• On-chip 4x Phase Locked Loop (PLL) to boost 
internal operating frequency on select internal and 
external oscillator sources.
• Software-controllable switching between various 
clock sources.
• Software-controllable postscaler for selective 
clocking of CPU for system power savings.
• System frequency range declaration bits for EC 
mode. When using an external clock source, the 
current consumption is reduced by setting the 
declaration bits to the expected frequency range.
• A Fail-Safe Clock Monitor (FSCM) that detects clock 
failure and permits safe application recovery or 
shutdown.
 provides a simplified diagram of the oscillator
system.
FIGURE 9-1:
PIC24F16KA102 FAMILY CLOCK DIAGRAM 
Note:
This data sheet summarizes the fea-
tures of this group of PIC24F devices. It
is not intended to be a comprehensive
reference source. For more information
on Oscillator Configuration, refer to the
“PIC24F Family Reference Manual”
,
Section 38. “Oscillator with 500 kHz
Low-Power FRC”
 (DS39726).
Secondary Oscillator
SOSCEN
Enable
Oscillator
SOSCO
SOSCI
Clock Source Option 
for Other Modules
OSCI
OSCO
Primary Oscillator
XT, HS, EC
P
os
tsca
ler
CLKDIV<10:8>
WDT, PWRT, DSWDT
FRCDIV
31 kHz (nominal)
8 MHz
FRC
LPRC
Oscillator
SOSC
LPRC
Clock Control Logic
Fail-Safe
Clock
Monitor
FRC
4 x PLL
XTPLL, HSPLL
ECPLL,FRCPLL
8 MHz
4 MHz
CPU
Peripherals
P
o
st
sca
ler
CLKDIV<14:12>
CLKO
Reference Clock
Generator
REFO
REFOCON<15:8>
Oscillator
500 kHz
LPFRC
Oscillator