
2006 Microchip Technology Inc.
Preliminary
DS70178C-page 207
dsPIC30F1010/202X
18.4
PRIMARY OSCILLATOR ON OSC1/
OSC2 PINS:
FIGURE 18-3:
PRIMARY OSCILLATOR
18.5
EXTERNAL CLOCK INPUT
Two of the primary Oscillator modes use an external
clock. These modes are EC and EC with IO.
driven by CMOS drivers. In this mode, the OSC1 pin is
high-impedance and the OSC2 pin is the clock output
(FOSC/2). This output clock is useful for testing or
synchronization purposes.
can be driven by CMOS drivers. In this mode, the
OSC1 pin is high-impedance and the OSC2 pin
becomes a general purpose I/O pin. The feedback
device between OSC1 and OSC2 is turned off to save
current.
FIGURE 18-4:
EXTERNAL CLOCK INPUT OPERATION (EC OSCILLATOR CONFIGURATION)
FIGURE 18-5:
EXTERNAL CLOCK INPUT OPERATION (ECIO OSCILLATOR CONFIGURATION)
C1
C2
XTAL
OSC2/CLKO
Rs (1)
OSC1/CLKI
RF (2)
Note 1: A series resistor, Rs, may be required for AT strip cut crystals.
2: The feedback resistor, RF, is typically in the range of 2 to 10 M
Ω.
To CLKGEN
CLKO/RC15
OSC1
OSC2
FOSC/2
dsPIC30F
Clock from Ext System
OSC1
I/O (OSC2)
I/O
dsPIC30F
Clock from Ext System