PIC16LF1824T39A_12 Datasheet, PDF (53/418 Pages) Microchip Technology – 20-Pin Flash Microcontrollers with XLP Technology

5.2.1.4 4xPLL
The oscillator module contains a 4xPLL that can be
used with both external and internal clock sources to
provide a system clock source. The input frequency for
the 4xPLL must fall within specifications. See the PLL
Clock Timing Specifications in Section 31.0
“Electrical Specifications”.
The 4xPLL may be enabled for use by one of two
methods:
1. Program the PLLEN bit in Configuration Word 2
to a ‘1’.
2. Write the SPLLEN bit in the OSCCON register to
a ‘1’. If the PLLEN bit in Configuration Word 2 is
programmed to a ‘1’, then the value of SPLLEN
is ignored.
5.2.1.5 TIMER1 Oscillator
The Timer1 Oscillator is a separate crystal oscillator
that is associated with the Timer1 peripheral. It is opti-
mized for timekeeping operations with a 32.768 kHz
crystal connected between the T1OSO and T1OSI
device pins.
The Timer1 Oscillator can be used as an alternate
system clock source and can be selected during
run-time using clock switching. Refer to Section 5.3
“Clock Switching” for more information.
FIGURE 5-5:
QUARTZ CRYSTAL
OPERATION (TIMER1
OSCILLATOR)
PIC^® MCU
T1OSI
C1
32.768 kHz
Quartz
Crystal
To Internal
Logic
C2
T1OSO
PIC16LF1824T39A
Note 1: Quartz crystal characteristics vary
according to type, package and
manufacturer. The user should consult the
manufacturer data sheets for specifications
and recommended application.
2: Always verify oscillator performance over
the VDD and temperature range that is
expected for the application.
3: For oscillator design assistance, reference
the following Microchip Applications Notes:
• AN826, “Crystal Oscillator Basics and
Crystal Selection for rfPIC^® and PIC^®
Devices” (DS00826)
• AN849, “Basic PIC^® Oscillator Design”
(DS00849)
• AN943, “Practical PIC^® Oscillator
Analysis and Design” (DS00943)
• AN949, “Making Your Oscillator Work”
(DS00949)
• TB097, “Interfacing a Micro Crystal
MS1V-T1K 32.768 kHz Tuning Fork
Crystal to a PIC16F690/SS” (DS91097)
• AN1288, “Design Practices for
Low-Power External Oscillators”
(DS01288)
 2012 Microchip Technology Inc.
Preliminary
DS41657A-page 53