70592C Datasheet, PDF (127/314 Pages) Microchip Technology – High-Performance, 16-bit Microcontrollers

PIC24HJXXXGPX06A/X08A/X10A
9.0 OSCILLATOR
CONFIGURATION
Note 1: This data sheet summarizes the features
of the PIC24HJXXXGPX06A/X08A/X10A
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” (DS70227) of
the “dsPIC33F/dsPIC33F/PIC24H Family
Reference Manual”, which is available
from the Microchip website
(www.microchip.com).
2: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
Section 4.0 “Memory Organization” in
this data sheet for device-specific register
and bit information.
The PIC24HJXXXGPX06A/X08A/X10A 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
• An Oscillator 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:
PIC24HJXXXGPX06A/X08A/X10A OSCILLATOR SYSTEM DIAGRAM
Primary Oscillator
OSC1
R⁽²⁾
S3
OSC2
S1
POSCMD<1:0>
PLL⁽¹⁾
XT, HS, EC
S2
XTPLL, HSPLL,
ECPLL, FRCPLL
S1/S3
DOZE<2:0>
FCY
FP⁽³⁾
FRC
Oscillator
FRCDIVN _S7
÷2
FOSC
TUN<5:0>
÷ 16
FRCDIV<2:0>
SOSCO
SOSCI
LPRC
Oscillator
Secondary Oscillator
LPOSCEN
FRCDIV16 _S6
FRC _S0
LPRC
S5
SOSC
S4
Clock Fail Clock Switch Reset
S7
NOSC<2:0> FNOSC<2:0>
WDT, PWRT,
FSCM
Timer 1
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.
3: The term, FP refers to the clock source for all the peripherals, while FCY refers to the clock source for the CPU. Through-
out this document FP and FCY are used interchangeably, except in the case of Doze mode. FP and FCY will be different
when Doze mode is used in any ratio other than 1:1, which is the default.
© 2011 Microchip Technology Inc.
DS70592C-page 127