Datasheet

PIC18F2220/2320/4220/4320
DS39599G-page 26 © 2007 Microchip Technology Inc.
FIGURE 2-8: PIC18F2X20/4X20 CLOCK DIAGRAM
PIC18F2X20/4X20
4 x PLL
CONFIG1H <3:0>
Secondary Oscillator
T1OSCEN
Enable
Oscillator
T1OSO
T1OSI
Clock Source Option
for Other Modules
OSC1
OSC2
Sleep
Primary Oscillator
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>