Datasheet

 2001-2013 Microchip Technology Inc. DS39582C-page 45
PIC16F87XA
TABLE 4-3: PORTB FUNCTIONS
TABLE 4-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
Name Bit# Buffer Function
RB0/INT bit 0 TTL/ST
(1)
Input/output pin or external interrupt input. Internal software programmable
weak pull-up.
RB1 bit 1 TTL Input/output pin. Internal software programmable weak pull-up.
RB2 bit 2 TTL Input/output pin. Internal software programmable weak pull-up.
RB3/PGM
(3)
bit 3 TTL Input/output pin or programming pin in LVP mode. Internal software
programmable weak pull-up.
RB4 bit 4 TTL Input/output pin (with interrupt-on-change). Internal software programmable
weak pull-up.
RB5 bit 5 TTL Input/output pin (with interrupt-on-change). Internal software programmable
weak pull-up.
RB6/PGC bit 6 TTL/ST
(2)
Input/output pin (with interrupt-on-change) or in-circuit debugger pin.
Internal software programmable weak pull-up. Serial programming clock.
RB7/PGD bit 7 TTL/ST
(2)
Input/output pin (with interrupt-on-change) or in-circuit debugger pin.
Internal software programmable weak pull-up. Serial programming data.
Legend: TTL = TTL input, ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt.
2: This buffer is a Schmitt Trigger input when used in Serial Programming mode or in-circuit debugger.
3: Low-Voltage ICSP Programming (LVP) is enabled by default which disables the RB3 I/O function. LVP
must be disabled to enable RB3 as an I/O pin and allow maximum compatibility to the other 28-pin and
40-pin mid-range devices.
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Value on:
POR, BOR
Value on
all other
Resets
06h, 106h PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xxxx xxxx uuuu uuuu
86h, 186h TRISB PORTB Data Direction Register 1111 1111 1111 1111
81h, 181h OPTION_REG RBPU INTEDG
T0CS T0SE PSA PS2 PS1 PS0 1111 1111 1111 1111
Legend: x = unknown, u = unchanged. Shaded cells are not used by PORTB.