Datasheet

 1997-2013 Microchip Technology Inc. DS30234E-page 125
PIC16C6X
13.2 Oscillator Configurations
13.2.1 OSCILLATOR TYPES
The PIC16CXX can be operated in four different oscil-
lator modes. The user can program two configuration
bits (FOSC1 and FOSC0) to select one of these four
modes:
• LP Low Power Crystal
• XT Crystal/Resonator
• HS High Speed Crystal/Resonator
• RC Resistor/Capacitor
13.2.2 CRYSTAL OSCILLATOR/CERAMIC
RESONATORS
In LP, XT, or HS modes a crystal or ceramic resonator
is connected to the OSC1/CLKIN and OSC2/CLKOUT
pins to establish oscillation (Figure 13-4). The
PIC16CXX oscillator design requires the use of a par-
allel cut crystal. Use of a series cut crystal may give a
frequency out of the crystal manufacturers specifica-
tions. When in LP, XT, or HS modes, the device can
have an external clock source to drive the OSC1/
CLKIN pin (Figure 13-5).
Applicable Devices
61 62 62A R62 63 R63 64 64A R64 65 65A R65 66 67
FIGURE 13-4: CRYSTAL/CERAMIC
RESONATOR OPERATION
(HS, XT OR LP OSC
CONFIGURATION)
FIGURE 13-5: EXTERNAL CLOCK INPUT
OPERATION (HS, XT OR LP
OSC CONFIGURATION)
C1
C2
XTAL
OSC2
Note1
OSC1
RF
SLEEP
To i nt er nal
logic
PIC16CXX
RS
See Table 13-1, Table 13-3, Table 13-2 and Table 13-4 for
recommended values of C1 and C2.
Note 1: A series resistor may be required for AT strip
cut crystals.
2: For the PIC16C61 the buffer is on the OSC2
pin, all other devices have the buffer on the
OSC1 pin.
(2)
(2)
To i nt er nal
logic
OSC1
OSC2
Open
Clock from
ext. system
PIC16CXX