PIC12F1516 MICROCHIP [Microchip Technology], PIC12F1516 Datasheet - Page 115

• Manufacturer Part Number: PIC12F1516
• Description: 28/40/44-Pin Flash Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

12.2
PORTA is a 8-bit wide, bidirectional port. The
corresponding data direction register is TRISA
(Register
corresponding PORTA pin an input (i.e., disable the
output driver). Clearing a TRISA bit (= 0) will make the
corresponding PORTA pin an output (i.e., enables
output driver and puts the contents of the output latch
on the selected pin).
initialize an I/O port.
Reading the PORTA register
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 (LATA).
The TRISA register
PORTA pin output drivers, even when they are being
used as analog inputs. The user should ensure the bits
in the TRISA register are maintained set when using
them as analog inputs. I/O pins configured as analog
input always read ‘0’.
12.2.1
The ANSELA register
configure the Input mode of an I/O pin to analog.
Setting the appropriate ANSELA 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 ANSELA bits has no affect on digital
output functions. A pin with TRIS clear and ANSEL 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.
 2010 Microchip Technology Inc.
Note:
PORTA Registers
12-3). Setting a TRISA bit (= 1) will make the
ANSELA REGISTER
The ANSELA register must be initialized
to configure an analog channel as a digital
input. Pins configured as analog inputs
will read ‘0’.
Example 12-1
(Register
(Register
(Register
12-3) controls the
12-5) is used to
12-2) reads the
shows how to
Preliminary
12.2.2
Each PORTA pin is multiplexed with other functions. The
pins, their combined functions and their output priorities
are shown in
When multiple outputs are enabled, the actual pin
control goes to the peripheral with the highest priority.
Analog input functions, such as ADC, are not shown in
the priority lists. These inputs are active when the I/O
pin is set for Analog mode using the ANSELx registers.
Digital output functions may control the pin when it is in
Analog mode with the priority shown in
TABLE 12-2:
Note 1:
PIC16(L)F1516/7/8/9
Pin Name
RA0
RA1
RA2
RA3
RA4
RA5
RA6
RA7
Priority listed from highest to lowest.
PORTA FUNCTIONS AND OUTPUT
PRIORITIES
Table
PORTA OUTPUT PRIORITY
12-2.
Function Priority
RA0
RA1
RA2
RA3
RA4
V
RA5
CLKOUT
OSC2
RA6
RA7
CAP
(PIC16F151X only)
DS41452B-page 115
Table
12-2.
(1)