DSPIC33FJ12MC202 Microchip Technology Inc., DSPIC33FJ12MC202 Datasheet - Page 97

• Manufacturer Part Number: DSPIC33FJ12MC202
• Description: High-performance, 16-bit Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

For example, suppose a 10 MHz crystal is being used
with the selected oscillator mode of XT with PLL.
• If PLLPRE<4:0> = 0, then N1 = 2. This yields a
• If PLLDIV<8:0> = 0x1E, then
• If PLLPOST<1:0> = 0, then N2 = 2. This provides
FIGURE 7-2:
TABLE 7-1:
© 2007 Microchip Technology Inc.
Fast RC Oscillator with Divide-by-N
(FRCDIVN)
Fast RC Oscillator with Divide-by-16
(FRCDIV16)
Low-Power RC Oscillator (LPRC)
Secondary (Timer1) Oscillator (SOSC)
Primary Oscillator (HS) with PLL
(HSPLL)
Primary Oscillator (XT) with PLL
(XTPLL)
Primary Oscillator (EC) with PLL
(ECPLL)
Primary Oscillator (HS)
Primary Oscillator (XT)
Primary Oscillator (EC)
Fast RC Oscillator with PLL (FRCPLL)
Fast RC Oscillator (FRC)
Note 1:
Source (Crystal, External Clock
or Internal RC)
VCO input of 10/2 = 5 MHz, which is within the
acceptable range of 0.8-8 MHz.
M = 32. This yields a VCO output of 5 x 32 = 160
MHz, which is within the 100-200 MHz ranged
needed.
a Fosc of 160/2 = 80 MHz. The resultant device
operating speed is 80/2 = 40 MIPS.
2:
Oscillator Mode
OSC2 pin function is determined by the OSCIOFNC Configuration bit.
This is the default oscillator mode for an unprogrammed (erased) device.
CONFIGURATION BIT VALUES FOR CLOCK SELECTION
dsPIC33FJ12MC201/202 PLL BLOCK DIAGRAM
Divide by
PLLPRE
2-33
Oscillator Source
0.8-8.0 MHz
Secondary
Primary
Primary
Primary
Primary
Primary
Primary
Internal
Internal
Internal
Internal
Internal
Here
Preliminary
dsPIC33FJ12MC201/202
X
EQUATION 7-3:
POSCMD<1:0>
Divide by
PLLDIV
F
2-513
VCO
CY
=
xx
xx
xx
xx
10
01
00
10
01
00
xx
xx
100-200 MHz
F
OSC
2
Here
=
1
2
(
PLLPOST
XT WITH PLL MODE
EXAMPLE
Divide by
10000000 * 32
2, 4, 8
FNOSC<2:0>
2 * 2
111
110
101
100
011
011
011
010
010
010
001
000
12.5-80 MHz
DS70265B-page 95
)
Here
=
40 MIPS
Note
1, 2
F
1
1
1
1
1
1
1
OSC