Datasheet
PIC18(L)F1XK22
DS40001365F-page 88 2009-2016 Microchip Technology Inc.
8.4 Port Analog Control
Some port pins are multiplexed with analog functions
such as the Analog-to-Digital Converter and
comparators. When these I/O pins are to be used as
analog inputs it is necessary to disable the digital input
buffer to avoid excessive current caused by improper
biasing of the digital input. Individual control of the
digital input buffers on pins which share analog
functions is provided by the ANSEL and ANSELH
registers. Setting an ANSx bit high will disable the
associated digital input buffer and cause all reads of
that pin to return ‘0’ while allowing analog functions of
that pin to operate correctly.
The state of the ANSx bits has no affect on digital
output functions. A pin with the associated TRISx bit
clear and ANSx bit set will still operate as a digital
output but the Input mode will be analog.
REGISTER 8-14: ANSEL: ANALOG SELECT REGISTER
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
ANS7 ANS6 ANS5 ANS4 ANS3 ANS2 ANS1 ANS0
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 ANS7: RC3 Analog Select Control bit
1 = Digital input buffer of RC3 is disabled
0 = Digital input buffer of RC3 is enabled
bit 6 ANS6: RC2 Analog Select Control bit
1 = Digital input buffer of RC2 is disabled
0 = Digital input buffer of RC2 is enabled
bit 5 ANS5: RC1 Analog Select Control bit
1 = Digital input buffer of RC1 is disabled
0 = Digital input buffer of RC1 is enabled
bit 4 ANS4: RC0 Analog Select Control bit
1 = Digital input buffer of RC0 is disabled
0 = Digital input buffer of RC0 is enabled
bit 3 ANS3: RA4 Analog Select Control bit
1 = Digital input buffer of RA4 is disabled
0 = Digital input buffer of RA4 is enabled
bit 2 ANS2: RA2 Analog Select Control bit
1 = Digital input buffer of RA2 is disabled
0 = Digital input buffer of RA2 is enabled
bit 1 ANS1: RA1 Analog Select Control bit
1 = Digital input buffer of RA1 is disabled
0 = Digital input buffer of RA1 is enabled
bit 0 ANS0: RA0 Analog Select Control bit
1 = Digital input buffer of RA0 is disabled
0 = Digital input buffer of RA0 is enabled