Microchip Technology AC164112 Data Sheet
© 2009 Microchip Technology Inc.
DS41341E-page 55
PIC16F72X/PIC16LF72X
6.2.1
ANSELA REGISTER
The ANSELA register (Register 6-4) is used to
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.
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.
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.
REGISTER 6-4:
ANSELA: PORTA ANALOG SELECT REGISTER
U-0
U-0
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
—
—
ANSA5
ANSA4
ANSA3
ANSA2
ANSA1
ANSA0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-6
Unimplemented: Read as ‘0’
bit 5-0
ANSA<5:0>: Analog Select between Analog or Digital Function on pins RA<5:0>, respectively
0
= Digital I/O. Pin is assigned to port or Digital special function.
1
= Analog input. Pin is assigned as analog input
(1)
. Digital Input buffer disabled.
Note 1:
When setting a pin to an analog input, the corresponding TRIS bit must be set to Input mode in order to
allow external control of the voltage on the pin.
allow external control of the voltage on the pin.