Datasheet

PIC16F87X
DS30292C-page 32  2001 Microchip Technology Inc.
TABLE 3-3: PORTB FUNCTIONS
TABLE 3-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
Name Bit# Buffer Function
RB0/INT bit0 TTL/ST
(1)
Input/output pin or external interrupt input. Internal software
programmable weak pull-up.
RB1 bit1 TTL Input/output pin. Internal software programmable weak pull-up.
RB2 bit2 TTL Input/output pin. Internal software programmable weak pull-up.
RB3/PGM
(3)
bit3 TTL Input/output pin or programming pin in LVP mode. Internal software
programmable weak pull-up.
RB4 bit4 TTL Input/output pin (with interrupt-on-change). Internal software programmable
weak pull-up.
RB5 bit5 TTL Input/output pin (with interrupt-on-change). Internal software programmable
weak pull-up.
RB6/PGC bit6 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 bit7 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.
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.