Datasheet
© 2009 Microchip Technology Inc. DS39775C-page 141
PIC18F87J50 FAMILY
TABLE 10-4: PORTA FUNCTIONS
Pin Name Function
TRIS
Setting
I/O
I/O
Type
Description
RA0/AN0 RA0
0 O DIG LATA<0> data output; not affected by analog input.
1 I TTL PORTA<0> data input; disabled when analog input enabled.
AN0
1 I ANA A/D input channel 0. Default input configuration on POR; does not
affect digital output.
RA1/AN1 RA1
0 O DIG LATA<1> data output; not affected by analog input.
1 I TTL PORTA<1> data input; disabled when analog input enabled.
AN1
1 I ANA A/D input channel 1. Default input configuration on POR; does not
affect digital output.
RA2/AN2/V
REF-RA2 0 O DIG LATA<2> data output; not affected by analog input. Disabled when
CV
REF output enabled.
1 I TTL PORTA<2> data input. Disabled when analog functions enabled;
disabled when CV
REF output enabled.
AN2
1 I ANA A/D input channel 2 . Default input configuration on POR; not affected
by analog output.
V
REF- 1 I ANA A/D low reference voltage input.
RA3/AN3/V
REF+RA3 0 O DIG LATA<3> data output; not affected by analog input.
1 I TTL PORTA<3> data input; disabled when analog input enabled.
AN3
1 I ANA A/D input channel 3. Default input configuration on POR.
V
REF+ 1 I ANA A/D high reference voltage input.
RA4/T0CKI/
PMD5
RA4
0 O DIG LATA<4> data output.
1 I ST PORTA<4> data input; default configuration on POR.
T0CKI
x I ST Timer0 clock input.
PMD5
(1,2)
x O DIG Parallel Master Port data output.
x I TTL Parallel Master Port data output.
RA5/PMD4/
AN4/C2INA
RA5
0 O DIG LATA<5> data output; not affected by analog input.
1 I TTL PORTA<5> data input; disabled when analog input enabled.
PMD4
(1,2)
x O DIG Parallel Master Port data output.
x I TTL Parallel Master Port data output.
AN4
1 I ANA A/D input channel 4. Default configuration on POR.
C2INA
1 I ANA Comparator2 input A.
Legend: O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: When PMPMX = 0.
2: Available on 80-pin devices only.