PIC16LF18854 Datasheet, PDF (114/668 Pages) Microchip Technology – C Compiler Optimized RISC Architecture

PIC16(L)F18856/76
6.2.2 INTERNAL CLOCK SOURCES
The device may be configured to use the internal
oscillator block as the system clock by performing one
of the following actions:
• Program the RSTOSC<2:0> bits in Configuration
Words to select the INTOSC clock source, which
will be used as the default system clock upon a
device Reset.
• Write the NOSC<2:0> bits in the OSCCON1
register to switch the system clock source to the
internal oscillator during run-time. See
Section 6.3 “Clock Switching” for more
information.
In INTOSC mode, OSC1/CLKIN is available for general
purpose I/O. OSC2/CLKOUT is available for general
purpose I/O or CLKOUT.
The function of the OSC2/CLKOUT pin is determined
by the CLKOUTEN bit in Configuration Words.
The internal oscillator block has two independent
oscillators that can produce two internal system clock
sources.
1. The HFINTOSC (High-Frequency Internal
Oscillator) is factory calibrated and operates up
to 32 MHz. The frequency of HFINTOSC can be
selected through the OSCFRQ Frequency
Selection register, and fine-tuning can be done
via the OSCTUNE register.
2. The LFINTOSC (Low-Frequency Internal
Oscillator) is factory-calibrated and operates at
31 kHz.
6.2.2.1 HFINTOSC
The High-Frequency Internal Oscillator (HFINTOSC) is
a precision digitally-controlled internal clock source
that produces a stable clock up to 32 MHz. The
HFINTOSC can be enabled through one of the
following methods:
• Programming the RSTOSC<2:0> bits in
Configuration Word 1 to ‘110’ (1 MHz) or ‘000’
(32 MHz) to set the oscillator upon device
Power-up or Reset.
• Write to the NOSC<2:0> bits of the OSCCON1
register during run-time.
The HFINTOSC frequency can be selected by setting
the HFFRQ<2:0> bits of the OSCFRQ register.
The NDIV<3:0> bits of the OSCCON1 register allow for
division of the HFINTOSC output from a range between
1:1 and 1:512.
DS40001824A-page 114
Preliminary
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