PIC24FJ16MC101_12 Datasheet, PDF (103/350 Pages) Microchip Technology – 16-bit Microcontrollers (up to 32 KB Flash and 2 KB SRAM)

PIC24FJ16MC101/102 AND PIC24FJ32MC101/102/104
8.1.3 PLL CONFIGURATION
The primary oscillator and internal FRC oscillator can
optionally use an on-chip 4x PLL to obtain higher
speeds of operation.
For example, suppose a 8 MHz crystal is being used
with the selected oscillator mode of MS with PLL. This
provides a Fosc of 8 MHz * 4 = 32 MHz. The resultant
device operating speed is 32/2 = 16 MIPS.
EQUATION 8-2: MS WITH PLL MODE
EXAMPLE
FCY
=
-^F----^O---^S---^C--
2
=
1--
2
(
8000000
⋅4
)
=
16 MIPS
TABLE 8-1: CONFIGURATION BIT VALUES FOR CLOCK SELECTION
Oscillator Mode
Oscillator
Source
POSCMD<1:0>
Fast RC Oscillator with Divide-by-n (FRCDIVN)
Internal
xx
Fast RC Oscillator with Divide-by-16 (FRCDIV16)
Internal
xx
Low-Power RC Oscillator (LPRC)
Internal
xx
Secondary (Timer1) Oscillator (SOSC)
Secondary
xx
Primary Oscillator (MS) with PLL (MSPLL)
Primary
01
Primary Oscillator (EC) with PLL (ECPLL)
Primary
00
Primary Oscillator (HS)
Primary
10
Primary Oscillator (MS)
Primary
01
Primary Oscillator (EC)
Primary
00
Fast RC Oscillator (FRC) with Divide-by-n and
Internal
xx
PLL (FRCPLL)
Fast RC Oscillator (FRC)
Internal
xx
Note 1: OSC2 pin function is determined by the OSCIOFNC Configuration bit.
2: This is the default oscillator mode for an unprogrammed (erased) device.
FNOSC<2:0>
111
110
101
100
011
011
010
010
010
001
000
See
Note
1, 2
1
1
1
—
1
—
—
1
1
1
© 2011-2012 Microchip Technology Inc.
Preliminary
DS39997C-page 103