PIC16LF1938-I/ML Microchip Technology, PIC16LF1938-I/ML Datasheet - Page 135

• Manufacturer Part Number: PIC16LF1938-I/ML
• Description: IC MCU 8BIT FLASH 28QFN
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 16Fr

Specifications of PIC16LF1938-I/ML

• Core Size: 8-Bit
• Program Memory Size: 28KB (16K x 14)
• Core Processor: PIC
• Speed: 32MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 25
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Controller Family/series: PIC16LF
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 1024Byte
• Cpu Speed: 32MHz
• No. Of Timers: 5
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12.3
PORTB is an 8-bit wide, bidirectional port. The
corresponding
(Register 12-7). 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 12-2 shows how to initialize PORTB.
Reading the PORTB register (Register 12-6) 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 (LATB).
The TRISB register (Register 12-7) 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’.
12.3.1
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 12-10). 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 WPUEN bit of the OPTION
register.
12.3.2
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. The
interrupt-on-change feature is disabled on a Power-on
Reset.
“Interrupt-On-Change” for more information.
 2009 Microchip Technology Inc.
PORTB Registers
WEAK PULL-UPS
INTERRUPT-ON-CHANGE
data
Reference
direction
register
Section 13.0
is
TRISB
Preliminary
12.3.3
The ANSELB register (Register 12-9) 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
when executing read-modify-write instructions on the
affected port.
EXAMPLE 12-2:
BANKSEL PORTB
CLRF
BANKSEL LATB
CLRF
BANKSEL ANSELB
CLRF
BANKSEL TRISB
MOVLW
MOVWF
PIC16F193X/LF193X
Note:
PORTB
LATB
ANSELB
B’11110000’ ;Set RB<7:4> as inputs
TRISB
ANSELB REGISTER
The ANSELB register must be initialized to
configure an analog channel as a digital
input. Pins configured as analog inputs will
read ‘0’.
INITIALIZING PORTB
;
;Init PORTB
;Data Latch
;
;Make RB<7:0> digital
;
;and RB<3:0> as outputs
;
DS41364D-page 135