Datasheet

 2010 Microchip Technology Inc. DS39616D-page 35
PIC18F2331/2431/4331/4431
FIGURE 3-8: PIC18F2331/2431/4331/4431 CLOCK DIAGRAM
4 x PLL
CONFIG1H <3:0>
T1OSCEN
Enable
Oscillator
T1OSO
T1OSI
Clock Source Option
for other Modules
OSC1
OSC2
Sleep
HSPLL
LP, XT, HS, RC, EC
T1OSC
CPU
Peripherals
IDLEN
Postscaler
MUX
MUX
8 MHz
4 MHz
2 MHz
1 MHz
500 kHz
125 kHz
250 kHz
OSCCON<6:4>
111
110
101
100
011
010
001
000
31 kHz
INTRC
Source
Internal
Oscillator
Block
WDT, FSCM
8 MHz
Internal Oscillator
(INTOSC)
OSCCON<6:4>
Clock
Control
OSCCON<1:0>
Primary Oscillator
Secondary Oscillator