PIC16F726-E/SO Microchip Technology, PIC16F726-E/SO Datasheet - Page 62

• Manufacturer Part Number: PIC16F726-E/SO
• Description: 14KB Flash Program, 1.8V-5.5V, 16MHz Internal Oscillator, 8b ADC, CCP, I2C/SPI,
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 16Fr

Specifications of PIC16F726-E/SO

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 25
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: FLASH
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 11x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 28-SOIC (7.5mm Width)
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 368 B
• Interface Type: I2C, SCI, SPI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 25
• Number Of Timers: 3
• Maximum Operating Temperature: + 125 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, 11 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164112 - VOLTAGE LIMITER MPLAB ICD2 VPPICE2000 - EMULATOR MPLAB-ICE 2000 POD
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

PIC16F72X/PIC16LF72X
6.3
PORTB is an 8-bit wide, bidirectional port. The
corresponding
(Register 6-6). Setting a TRISB bit (= 1) will make the
corresponding PORTB pin an input (i.e., put the
corresponding output driver in a High-Impedance mode).
Clearing a TRISB bit (= 0) will make the corresponding
PORTB pin an output (i.e., enable the output driver and
put the contents of the output latch on the selected pin).
Example 6-2 shows how to initialize PORTB.
Reading the PORTB register (Register 6-5) reads the
status of the pins, whereas writing to it will write to the
PORT latch. All write operations are read-modify-write
operations. Therefore, a write to a port implies that the
port pins are read, this value is modified and then written
to the PORT data latch.
The TRISB register (Register 6-6) controls the PORTB
pin output drivers, even when they are being used as
analog inputs. The user should ensure the bits in the
TRISB register are maintained set when using them as
analog inputs. I/O pins configured as analog input always
read ‘0’. Example 6-2 shows how to initialize PORTB.
EXAMPLE 6-2:
DS41341E-page 62
BANKSEL PORTB
CLRF
BANKSEL ANSELB
CLRF
BANKSEL TRISB
MOVLW
MOVWF
Note:
PORTB and TRISB Registers
PORTB
ANSELB
B’11110000’ ;Set RB<7:4> as inputs
TRISB
The ANSELB register must be initialized to
configure an analog channel as a digital
input. Pins configured as analog inputs will
read ‘0’.
data
INITIALIZING PORTB
direction
;
;Init PORTB
;Make RB<7:0> digital
;
;and RB<3:0> as outputs
;
register
is
TRISB
6.3.1
The ANSELB register (Register 6-9) is used to
configure the Input mode of an I/O pin to analog.
Setting the appropriate ANSELB bit high will cause all
digital reads on the pin to be read as ‘0’ and allow
analog functions on the pin to operate correctly.
The state of the ANSELB bits has no affect on digital
output functions. A pin with TRIS clear and ANSELB
set will still operate as a digital output, but the Input
mode will be analog. This can cause unexpected
behavior
instructions on the affected port.
6.3.2
Each of the PORTB pins has an individually configurable
internal weak pull-up. Control bits WPUB<7:0> enable or
disable each pull-up (see Register 6-7). Each weak
pull-up is automatically turned off when the port pin is
configured as an output. All pull-ups are disabled on a
Power-on Reset by the RBPU bit of the OPTION register.
6.3.3
All of the PORTB pins are individually configurable as an
interrupt-on-change pin. Control bits IOCB<7:0> enable
or disable the interrupt function for each pin. Refer to
Register 6-8.
disabled on a Power-on Reset.
For enabled interrupt-on-change pins, the present value
is compared with the old value latched on the last read
of PORTB to determine which bits have changed or
mismatched the old value. The ‘mismatch’ outputs of
the last read are OR’d together to set the PORTB
Change Interrupt flag bit (RBIF) in the INTCON register.
This interrupt can wake the device from Sleep. The user,
in the Interrupt Service Routine, clears the interrupt by:
a)
b)
A mismatch condition will continue to set flag bit RBIF.
Reading or writing PORTB will end the mismatch
condition and allow flag bit RBIF to be cleared. The latch
holding the last read value is not affected by a MCLR nor
Brown-out Reset. After these Resets, the RBIF flag will
continue to be set if a mismatch is present.
Note:
Any read or write of PORTB. This will end the
mismatch condition.
Clear the flag bit RBIF.
ANSELB REGISTER
WEAK PULL-UPS
INTERRUPT-ON-CHANGE
When a pin change occurs at the same
time as a read operation on PORTB, the
RBIF flag will always be set. If multiple
PORTB pins are configured for the
interrupt-on-change, the user may not be
able to identify which pin changed state.
when
The
interrupt-on-change
executing
© 2009 Microchip Technology Inc.
read-modify-write
feature
is