Datasheet

© 2009 Microchip Technology Inc. DS70175H-page 121
PIC24HJXXXGPX06/X08/X10
9.0 OSCILLATOR
CONFIGURATION
The PIC24HJXXXGPX06/X08/X10 oscillator system
provides:
• Various external and internal oscillator options as
clock sources
• An on-chip PLL to scale the internal operating
frequency to the required system clock frequency
• The internal FRC oscillator can also be used with
the PLL, thereby allowing full-speed operation
without any external clock generation hardware
• Clock switching between various clock sources
• Programmable clock postscaler for system power
savings
• A Fail-Safe Clock Monitor (FSCM) that detects
clock failure and takes fail-safe measures
• A Clock Control register (OSCCON)
• Nonvolatile Configuration bits for main oscillator
selection.
A simplified diagram of the oscillator system is shown
in Figure 9-1.
FIGURE 9-1: PIC24HJXXXGPX06/X08/X10 OSCILLATOR SYSTEM DIAGRAM
Note: This data sheet summarizes the features
of the PIC24HJXXXGPX06/X08/X10 fam-
ily of devices. However, it is not intended
to be a comprehensive reference source.
To complement the information in this data
sheet, refer to the “PIC24H Family Refer-
ence Manual”, Section 7. “Oscillator”
(DS70227), which is available from the
Microchip website (www.microchip.com).
PIC24H
Secondary Oscillator
LPOSCEN
SOSCO
SOSCI
Timer 1
XTPLL, HSPLL,
XT, HS, EC
FRCDIV<2:0>
WDT, PWRT,
FSCM
FRCDIVN
SOSC
FRCDIV16
ECPLL, FRCPLL
NOSC<2:0> FNOSC<2:0>
Reset
FRC
Oscillator
LPRC
Oscillator
DOZE<2:0>
S3
S1
S2
S1/S3
S7
S6
FRC
LPRC
S0
S5
S4
÷16
Clock Switch
S7
Clock Fail
÷
2
TUN<5:0>
PLL
(1)
FCY
FOSC
FRCDIV
DOZE
Note 1: See Figure 9-2 for PLL details.
2: If the Oscillator is used with XT or HS modes, an extended parallel resistor with the value of 1 MΩ must be connected.
OSC2
OSC1
Primary Oscillator
R
(2)
POSCMD<1:0>
FP