PIC16F913-I/SP Microchip Technology Inc., PIC16F913-I/SP Datasheet - Page 77

• Manufacturer Part Number: PIC16F913-I/SP
• Description: 28 PIN, 7 KB FLASH, 352 RAM, 25 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F913-I/SP

• A/d Inputs: 5-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 25
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• Programmable Memory: 7K Bytes
• Ram Size: 256 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

4.3.4
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/CLKO 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 4-5 shows the RC mode connections.
FIGURE 4-5:
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 4-6 shows the RCIO mode connections.
FIGURE 4-6:
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.
© 2005 Microchip Technology Inc.
EXT
Recommended values:3 k
R
R
Recommended values: 3 k
V
V
EXT
EXT
SS
SS
values. The user also needs to take into account
V
V
DD
DD
C
C
EXTERNAL RC MODES
EXT
EXT
F
RA6
OSC
/4
RC MODE
RCIO MODE
OSC1
OSC1
I/O (OSC2)
OSC2/CLKO
PIC16F917/916/914/913
PIC16F917/916/914/913
C
EXT
EXT
C
EXT
) and capacitor (C
> 20 pF
R
> 20 pF
EXT
R
EXT
100 k
100 k
Internal
Internal
Clock
Clock
EXT
Preliminary
)
PIC16F917/916/914/913
4.4
The PIC16F917/916/914/913 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 4.5 “Clock Switching”).
4.4.1
The INTOSC and INTOSCIO 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 16-1).
In INTOSC mode, the OSC1 pin is available for general
purpose I/O. The OSC2/CLKO pin outputs the selected
internal oscillator frequency divided by 4. The CLKO
signal may be used to provide a clock for external
circuitry, synchronization, calibration, test or other
application requirements.
In INTOSCIO mode, the OSC1 and OSC2 pins are
available for general purpose I/O.
4.4.2
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 4-2).
The output of the HFINTOSC connects to a postscaler
and multiplexer (see Figure 4-1). One of seven
frequencies can be selected via software using the
IRCF bits (see Section 4.4.4 “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 4-2).
The
Oscillator) is uncalibrated and operates at
approximately 31 kHz.
Internal Clock Modes
HFINTOSC
LFINTOSC
INTOSC AND INTOSCIO MODES
HFINTOSC
of
the
HFINTOSC
(High-Frequency
(Low-Frequency
can
DS41250E-page 75
000) as the
be
000).
Internal
Internal
altered