PIC12F1822 MICROCHIP [Microchip Technology], PIC12F1822 Datasheet - Page 57

• Manufacturer Part Number: PIC12F1822
• Description: 8/14-Pin Flash Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

FIGURE 5-3:
 2010 Microchip Technology Inc.
Note 1: A series resistor (R
Note 1: Quartz crystal characteristics vary according
C1
C2
2: The value of R
2: Always verify oscillator performance over
3: For oscillator design assistance, reference
quartz crystals with low drive level.
selected (typically between 2 M to 10 M.
• AN826, “Crystal Oscillator Basics and
• AN849, “Basic PIC
• AN943, “Practical PIC
• AN949, “Making Your Oscillator Work”
to type, package and manufacturer. The
user should consult the manufacturer data
sheets for specifications and recommended
application.
the V
expected for the application.
the following Microchip Applications Notes:
Crystal Selection for rfPIC
Devices” (DS00826)
(DS00849)
Analysis and Design” (DS00943)
(DS00949)
Quartz
Crystal
R
S
DD
(1)
and temperature range that is
QUARTZ CRYSTAL
OPERATION (LP, XT OR
HS MODE)
F
varies with the Oscillator mode
OSC1/CLKIN
OSC2/CLKOUT
R
S
F
PIC
) may be required for
(2)
®
Oscillator Design”
®
®
MCU
Oscillator
®
and PIC
Sleep
To Internal
Logic
PIC12F/LF1822/16F/LF1823
®
Preliminary
FIGURE 5-4:
5.2.1.3
If the oscillator module is configured for LP, XT or HS
modes, the Oscillator Start-up Timer (OST) counts
1024 oscillations from OSC1. This occurs following a
Power-on Reset (POR) and when the Power-up Timer
(PWRT) has expired (if configured), or a wake-up from
Sleep. During this time, the program counter does not
increment and program execution is suspended. The
OST ensures that the oscillator circuit, using a quartz
crystal resonator or ceramic resonator, has started and
is providing a stable system clock to the oscillator
module.
In order to minimize latency between external oscillator
start-up and code execution, the Two-Speed Clock
Start-up mode can be selected (see Section 5.4
“Two-Speed Clock Start-up Mode”).
5.2.1.4
The oscillator module contains a 4X PLL that can be
used with both external and internal clock sources to
provide a system clock source. The input frequency for
the 4X PLL must fall within specifications. See the PLL
Clock
“Electrical Specifications”.
The 4X PLL may be enabled for use by one of two
methods:
1.
2.
Note 1: A series resistor (R
Program the PLLEN bit in Configuration Word 2
to a ‘1’.
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.
C1
C2 Ceramic
2: The value of R
3: An additional parallel feedback resistor (R
Timing
Resonator
ceramic resonators with low drive level.
selected (typically between 2 M to 10 M.
may be required for proper ceramic resonator
operation.
Oscillator Start-up Timer (OST)
4X PLL
R
Specifications
P (3)
R
S (1)
CERAMIC RESONATOR
OPERATION
(XT OR HS MODE)
F
varies with the Oscillator mode
OSC1/CLKIN
OSC2/CLKOUT
S
R
) may be required for
PIC
F
(2)
®
in
DS41413A-page 57
MCU
Section 29.0
To Internal
Logic
Sleep
P
)