Datasheet

PIC18(L)F1XK22
DS41365E-page 14  2009-2011 Microchip Technology Inc.
FIGURE 2-1: PIC
®
MCU CLOCK SOURCE BLOCK DIAGRAM
4 x PLL
FOSC<3:0>
OSC2
OSC1/T13CKI
Sleep
CPU
Peripherals
IDLEN
Postscaler
MUX
MUX
16 MHz
8 MHz
4 MHz
2 MHz
1 MHz
250 kHz
500 kHz
IRCF<2:0>
0x
110
101
100
011
010
001
000
31 kHz
31 kHz
LFINTOSC
Internal
Oscillator
Block
Clock
Control
SCS<1:0>
HFINTOSC
16 MHz
0
1
INTSRC
Primary
PIC18(L)F1XK22
Sleep
Sleep
System
PCLKEN
PRI_SD
0
1
FOSC<3:0>
PLL_EN
PLLEN
Oscillator,
Watchdog
Timer
Fail-Safe
Clock
Two-Speed
Start-up
Clock
Timer1/Timer3
External
Secondary
Oscillator
and
LP, XT, HS, RC, EC,
Secondary Osc.
T1OSCEN
Internal Osc.
1x
Note: If using a low-frequency external oscillator
and want to multiple it by 4 via PLL, the
ideal input frequency is from 4 MHz to 16
MHz.