PIC16F193X Datasheet, PDF (109/418 Pages) Microchip Technology – 28/40/44-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver and nanoWatt Technology

PIC16F193X/LF193X
8.0 OSCILLATOR MODULE (WITH
FAIL-SAFE CLOCK MONITOR)
8.1 Overview
The oscillator module has a wide variety of clock
sources and selection features that allow it to be used
in a wide range of applications while maximizing perfor-
mance and minimizing power consumption. Figure 8-1
illustrates a block diagram of the oscillator module.
Clock sources can be configured from external
oscillators, quartz crystal resonators, ceramic resonators
and Resistor-Capacitor (RC) circuits. In addition, the
system clock source can be configured from one of three
internal oscillators, with a choice of speeds selectable via
software. Additional clock features include:
• Selectable system clock source between external
or internal via software.
• Two-Speed Start-up mode, which minimizes
latency between external oscillator start-up and
code execution.
• Fail-Safe Clock Monitor (FSCM) designed to
detect a failure of the external clock source (LP,
XT, HS, EC or RC modes) and switch
automatically to the internal oscillator.
The oscillator module can be configured in one of six
clock modes.
1. EC – External clock.
2. LP – 32 kHz Low-Power Crystal mode.
3. XT – Medium Gain Crystal or Ceramic Resonator
Oscillator mode.
4. HS – High Gain Crystal or Ceramic Resonator
mode.
5. RC – External Resistor-Capacitor (RC).
6. INTOSC – Internal oscillator.
Clock Source modes are configured by the FOSC<2:0>
bits in the Configuration Word Register 1 (CONFIG1).
The internal clock can be generated from two internal
oscillators. The HFINTOSC is a calibrated
high-frequency oscillator. The MFINTOSC is a
calibrated medium-frequency oscillator. The
LFINTOSC is an uncalibrated low-frequency oscillator.
FIGURE 8-1:
SIMPLIFIED PIC^® MCU CLOCK SOURCE BLOCK DIAGRAM
OSC2
OSC1
T1OSO
T1OSI
External
Oscillator
Sleep
Oscillator ^Timer1
T1OSCEN
Enable
Oscillator
Internal
Oscillator
Block
16 MHz
Source
31 kHz
Source
16 MHz
(HFINTOSC)
500 kHz
Source
500 kHz
(MFINTOSC)
LP, XT, HS, RC, EC
4 x PLL
FOSC<2:0> = 100
T1OSC
Sleep
CPU and
Peripherals
IRCF<3:0>
16 MHz
8 MHz
4 MHz
2 MHz
1 MHz
500 kHz
250 kHz
125 kHz
62.5 kHz
31.25 kHz
31 kHz
Internal Oscillator
Clock
Control
FOSC<2:0> SCS<1:0>
Clock Source Option
for other modules
31 kHz (LFINTOSC)
WDT, PWRT, Fail-Safe Clock Monitor
Two-Speed Start-up and other modules
© 2008 Microchip Technology Inc.
Preliminary
DS41364A-page 107