PIC24F08KA102-I Datasheet, PDF (93/278 Pages) Microchip Technology – 20/28-Pin General Purpose, 16-Bit Flash Microcontrollers with nanoWatt XLP Technology

PIC24F16KA102 FAMILY
9.3 Control Registers
The operation of the oscillator is controlled by three
Special Function Registers (SFRs):
• OSCCON
• CLKDIV
• OSCTUN
The OSCCON register (Register 9-1) is the main con-
trol register for the oscillator. It controls clock source
switching and allows the monitoring of clock sources.
The Clock Divider register (Register 9-2) controls the
features associated with Doze mode, as well as the
postscaler for the FRC oscillator.
The FRC Oscillator Tune register (Register 9-3) allows
the user to fine tune the FRC oscillator over a range of
approximately ±5.25%. Each bit increment or decre-
ment changes the factory calibrated frequency of the
FRC oscillator by a fixed amount.
REGISTER 9-1: OSCCON: OSCILLATOR CONTROL REGISTER
U-0
R-0, HSC R-0, HSC R-0, HSC
U-0
—
COSC2
COSC1
COSC0
—
bit 15
R/W-x⁽¹⁾
NOSC2
R/W-x⁽¹⁾
NOSC1
R/W-x⁽¹⁾
NOSC0
bit 8
R/SO-0, HSC
U-0
R-0, HSC⁽²⁾
U-0
R/CO-0, HS
U-0
CLKLOCK
—
LOCK
—
CF
—
bit 7
R/W-0
SOSCEN
R/W-0
OSWEN
bit 0
Legend:
SO = Settable Only bit
R = Readable bit
-n = Value at POR
CO = Clearable Only bit
HS = Hardware Settable bit
W = Writable bit
‘1’ = Bit is set
HSC = Hardware Settable/Clearable bit
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 15
bit 14-12
bit 11
bit 10-8
Unimplemented: Read as ‘0’
COSC<2:0>: Current Oscillator Selection bits
111 = 8 MHz Fast RC Oscillator with Postscaler (FRCDIV)
110 = 500 kHz Low-Power Fast RC Oscillator (FRC) with Postscaler (LPFRCDIV)
101 = Low-Power RC Oscillator (LPRC)
100 = Secondary Oscillator (SOSC)
011 = Primary Oscillator with PLL module (XTPLL, HSPLL, ECPLL)
010 = Primary Oscillator (XT, HS, EC)
001 = 8 MHz FRC Oscillator with Postscaler and PLL module (FRCPLL)
000 = 8 MHz FRC Oscillator (FRC)
Unimplemented: Read as ‘0’
NOSC<2:0>: New Oscillator Selection bits⁽¹⁾
111 = 8 MHz Fast RC Oscillator with Postscaler (FRCDIV)
110 = 500 kHz Low-Power Fast RC Oscillator (FRC) with Postscaler (LPFRCDIV)
101 = Low-Power RC Oscillator (LPRC)
100 = Secondary Oscillator (SOSC)
011 = Primary Oscillator with PLL module (XTPLL, HSPLL, ECPLL)
010 = Primary Oscillator (XT, HS, EC)
001 = 8 MHz FRC Oscillator with Postscaler and PLL module (FRCPLL)
000 = 8 MHz FRC Oscillator (FRC)
Note 1: Reset values for these bits are determined by the FNOSC Configuration bits.
2: Also resets to ‘0’ during any valid clock switch or whenever a non-PLL Clock mode is selected.
 2008-2011 Microchip Technology Inc.
DS39927C-page 93