PIC16F636-I/ST Microchip Technology, PIC16F636-I/ST Datasheet - Page 34

• Manufacturer Part Number: PIC16F636-I/ST
• Description: IC MCU FLASH 2KX14 14TSSOP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F636-I/ST

• Program Memory Type: FLASH
• Program Memory Size: 3.5KB (2K x 14)
• Package / Case: 14-TSSOP
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Peripherals: Brown-out Detect/Reset, LVD, POR, WDT
• Number Of I /o: 11
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 128 B
• Interface Type: RS- 232/SPI/USB
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 2
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8 bit
• Package: 14TSSOP
• Device Core: PIC
• Family Name: PIC16
• Maximum Speed: 20 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC162057 - MPLAB ICD 2 HEADER 14DIP
• Eeprom Size: -
• Data Converters: -
• Connectivity: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC12F635/PIC16F636/639
3.3.4
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 the OSC1 pin.
The OSC2/CLKOUT pin 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 RC mode connections.
FIGURE 3-5:
In RCIO mode, the RC circuit is connected to the OSC1
pin. The OSC2 pin becomes an additional general
purpose I/O pin. The I/O pin becomes bit 4 of PORTA
(RA4). Figure 3-6 shows the RCIO mode connections.
FIGURE 3-6:
The RC oscillator frequency is a function of the supply
voltage, the resistor (R
values and the operating temperature. In addition to
this, the oscillator frequency will vary from unit to unit
due to normal threshold voltage. Furthermore, the
difference in lead frame capacitance between package
types will also affect the oscillation frequency or for low
C
variation due to tolerance of external RC components
used.
DS41232B-page 32
R
C
EXT
Recommended values: 3 k
V
Recommended values: 3 k
EXT
EXT
C
R
V
SS
EXT
EXT
SS
values. The user also needs to take into account
V
V
DD
DD
RA4
EXTERNAL RC MODES
F
OSC
/4
OSC1
I/O (OSC2)
OSC1
RCIO MODE
OSC2/CLKOUT
RC MODE
C
C
EXT
EXT
EXT
PIC12F635/PIC16F636/639
PIC12F635/PIC16F636/639
> 20 pF
> 20 pF
) and capacitor (C
R
R
EXT
EXT
100 k
100 k
Internal
Clock
Internal
Clock
EXT
Preliminary
)
3.4
The PIC12F635/PIC16F636/639 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 (IRCF)
bits.
The system clock can be selected between external or
internal clock sources via the System Clock Selection
(SCS) bit (see Section 3.5 “Clock Switching”).
3.4.1
The LFINTOSC and LFINTOSCIO modes configure
the internal oscillators as the system clock source
when the device is programmed using the oscillator
selection (FOSC) bits in the Configuration Word
register (Register 12-1).
In LFINTOSC mode, the OSC1 pin is available for
general purpose I/O. The OSC2/CLKOUT pin 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 LFINTOSCIO mode, the OSC1 and OSC2 pins are
available for general purpose I/O.
3.4.2
The High-Frequency Internal Oscillator (HFINTOSC) is
a factory calibrated 8 MHz internal clock source. The
frequency
approximately ±12% via software using the OSCTUNE
register (Register 3-1).
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 bits (see Section 3.4.4 “Frequency Select Bits
(IRCF)”).
The HFINTOSC is enabled by selecting any frequency
between 8 MHz and 125 kHz (IRCF
system clock source (SCS = 1), or when Two-Speed
Start-up is enabled (IESO = 1 and IRCF
The HF Internal Oscillator (HTS) bit (OSCCON<2>)
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 ±12% via software using the
OSCTUNE register (Register 3-1).
The
Oscillator) is uncalibrated and operates at
approximately 31 kHz.
Internal Clock Modes
HFINTOSC
LFINTOSC
LFINTOSC AND LFINTOSCIO
MODES
HFINTOSC
of
the
HFINTOSC
© 2005 Microchip Technology Inc.
(High-Frequency
(Low-Frequency
can
000) as the
000).
be
Internal
Internal
altered