PIC16F684-E/P Microchip Technology Inc., PIC16F684-E/P Datasheet - Page 25

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PIC16F684-E/P

Manufacturer Part Number
PIC16F684-E/P
Description
14 PIN, 3.5 KB FLASH, 128 RAM, 12 I/O
Manufacturer
Microchip Technology Inc.
Datasheet

Specifications of PIC16F684-E/P

A/d Inputs
8-Channel, 10-Bit
Comparators
2
Cpu Speed
5 MIPS
Eeprom Memory
256 Bytes
Input Output
12
Memory Type
Flash
Number Of Bits
8
Package Type
14-pin PDIP
Programmable Memory
3.5K Bytes
Ram Size
128 Bytes
Speed
20 MHz
Timers
2-8-bit, 1-16-bit
Voltage, Range
2-5.5 V
Lead Free Status / Rohs Status
RoHS Compliant part Electrostatic Device
3.4.4
The external Resistor-Capacitor (RC) modes support
the use of an external RC circuit. This allows the
designer maximum flexibility in frequency choice while
keeping costs to a minimum when clock accuracy is not
required. There are two modes: RC and RCIO.
In RC mode, the RC circuit connects to OSC1.
OSC2/CLKOUT outputs the RC oscillator frequency
divided by 4. This signal may be used to provide a clock
for external circuitry, synchronization, calibration, test
or other application requirements. Figure 3-5 shows
the external RC mode connections.
FIGURE 3-5:
In RCIO mode, the RC circuit is connected to OSC1.
OSC2 becomes an additional general purpose I/O pin.
The RC oscillator frequency is a function of the supply
voltage, the resistor (R
and the operating temperature. Other factors affecting
the oscillator frequency are:
• threshold voltage variation
• component tolerances
• packaging variations in capacitance
The user also needs to take into account variation due
to tolerance of external RC components used.
© 2006 Microchip Technology Inc.
R
C
Note 1:
V
Recommended values: 10 k
EXT
EXT
SS
V
F
I/O
OSC
DD
(2)
2:
/4 or
EXTERNAL RC MODES
Alternate pin functions are listed in
Section 1.0 “Device Overview”.
Output depends upon RC or RCIO Clock
mode.
OSC1/CLKIN
OSC2/CLKOUT
EXT
EXTERNAL RC MODES
3 k
C
EXT
) and capacitor (C
PICmicro
> 20 pF, 2-5V
R
R
EXT
EXT
(1)
100 k , 3-5V
®
100 k , <3V
MCU
EXT
Internal
Clock
) values
3.5
The Oscillator module has two independent, internal
oscillators that can be configured or selected as the
system clock source.
1.
2.
The system clock speed can be selected via software
using the Internal Oscillator Frequency Select bits
IRCF<2:0> of the OSCCON register.
The system clock can be selected between external or
internal clock sources via the System Clock Selection
(SCS) bit of the OSCCON register. See Section 3.6
“Clock Switching” for more information.
3.5.1
The INTOSC and INTOSCIO modes configure the
internal oscillators as the system clock source when
the device is programmed using the oscillator selection
or the FOSC<2:0> bits in the Configuration Word
register (CONFIG).
In INTOSC mode, OSC1/CLKIN is available for general
purpose I/O. OSC2/CLKOUT outputs the selected
internal oscillator frequency divided by 4. The CLKOUT
signal may be used to provide a clock for external
circuitry, synchronization, calibration, test or other
application requirements.
In INTOSCIO mode, OSC1/CLKIN and OSC2/CLKOUT
are available for general purpose I/O.
3.5.2
The High-Frequency Internal Oscillator (HFINTOSC) is
a factory calibrated 8 MHz internal clock source. The
frequency of the HFINTOSC can be altered via
software using the OSCTUNE register (Register 3-2).
The output of the HFINTOSC connects to a postscaler
and multiplexer (see Figure 3-1). One of seven
frequencies can be selected via software using the
IRCF<2:0> bits of the OSCCON register. See
Section 3.5.4 “Frequency Select Bits (IRCF)” for
more information.
The HFINTOSC is enabled by selecting any frequency
between 8 MHz and 125 kHz by setting the IRCF<2:0>
bits of the OSCCON register
System Clock Source (SCS) bit of the OSCCON
register to ‘1’ or enable Two-Speed Start-up by setting
the IESO bit in the Configuration Word register
(CONFIG) to ‘1’.
The HF Internal Oscillator (HTS) bit of the OSCCON
register indicates whether the HFINTOSC is stable or not.
The
Oscillator) is factory calibrated and operates at
8 MHz. The frequency of the HFINTOSC can be
user-adjusted via software using the OSCTUNE
register (Register 3-2).
The
Oscillator) is uncalibrated and operates at
31 kHz.
Internal Clock Modes
INTOSC AND INTOSCIO MODES
HFINTOSC
LFINTOSC
HFINTOSC
(High-Frequency
(Low-Frequency
PIC16F684
000. Then, set the
DS41202D-page 23
Internal
Internal

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