PIC16F721T-I/ML Microchip Technology, PIC16F721T-I/ML Datasheet - Page 68

• Manufacturer Part Number: PIC16F721T-I/ML
• Description: 7 KB FLASH, 256 B SRAM, 18 I/O 20 QFN 4x4mm T/R
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 16Fr

Specifications of PIC16F721T-I/ML

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 17
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 12x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIC16F/LF720/721
7.2
Clock source modes can be classified as external or
internal.
• Internal clock source (INTOSC) is contained
• The external clock mode (EC) relies on an
The system clock can be selected between external or
internal clock sources via the FOSC bits of the
Configuration Word 1.
7.3
The oscillator module has eight output frequencies
derived from a 500 kHz high precision oscillator. The
IRCF bits of the OSCCON register select the
postscaler applied to the clock source dividing the
frequency by 1, 2, 4 or 8. Setting the PLLEN bit of the
Configuration Word 1 locks the internal clock source to
16 MHz before the postscaler is selected by the IRCF
bits. The PLLEN bit must be set or cleared at the time
of programming; therefore, only the upper or low four
clock source frequencies are selectable in software.
Internal clock sources are contained internally within
the oscillator module. The internal oscillator block has
two internal oscillators and a dedicated Phase Locked
Loop that are used to generate three internal system
clock sources: the 16 MHz High-Frequency Internal
Oscillator (HFINTOSC) and the 500 kHz (MFINTOSC).
Both can be user-adjusted via software using the
OSCTUNE register
7.3.1
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 CONFIG1 register. See
Section 8.0
information.
In INTOSC mode, CLKIN is available for general
purpose I/O. 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, CLKIN and CLKOUT are available
for general purpose I/O.
DS41430A-page 68
within the oscillator module and derived from a
500 kHz high precision oscillator. The oscillator
module has eight selectable output frequencies,
with a maximum internal frequency of 16 MHz.
external signal for the clock source.
Clock Source Modes
Internal Clock Modes
INTOSC AND INTOSCIO MODES
“Device
(Register
Configuration”
7-2).
for
more
7.3.2
The output of the 500 kHz MFINTOSC and 16 MHz
HFINTOSC, with Phase Locked Loop enabled, connect
to a postscaler and multiplexer (see
Internal Oscillator Frequency Select bits (IRCF) of the
OSCCON register select the frequency output of the
internal oscillator. Depending upon the PLLEN bit, one
of four frequencies of two frequency sets can be
selected via software:
If PLLEN = 1, HFINTOSC frequency selection is as
follows:
• 16 MHz
• 8 MHz (default after Reset)
• 4 MHz
• 2 MHz
If PLLEN = 0, MFINTOSC frequency selection is as
follows:
• 500 kHz
• 250 kHz (default after Reset)
• 125 kHz
• 62.5 kHz
There is no start-up delay before a new frequency
selected in the IRCF bits takes effect. This is because
the old and new frequencies are derived from INTOSC
via the postscaler and multiplexer.
Start-up delay specifications are located in the
Table 23-2
Specifications”.
Note:
FREQUENCY SELECT BITS (IRCF)
Following any Reset, the IRCF<1:0> bits
of the OSCCON register are set to ‘10’ and
the frequency selection is set to 8 MHz or
250 kHz. The user can modify the IRCF
bits to select a different frequency.
in
 2010 Microchip Technology Inc.
Section 23.0
Figure
“Electrical
7-1). The