Datasheet

© 2009 Microchip Technology Inc. DS70286C-page 137
dsPIC33FJXXXGPX06/X08/X10
9.0 OSCILLATOR
CONFIGURATION
The dsPIC33FJXXXGPX06/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: dsPIC33FJXXXGPX06/X08/X10 OSCILLATOR SYSTEM DIAGRAM
Note: This data sheet summarizes the features
of the dsPIC33FJXXXGPX06/X08/X10
family of devices. However, it is not
intended to be a comprehensive reference
source. To complement the information in
this data sheet, refer to Section 7.
“Oscillator” (DS70186) in the “dsPIC33F
Family Reference Manual”, which is
available from the Microchip web site
(www.microchip.com).
dsPIC33F
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