PIC16F87XA Datasheet, PDF (47/234 Pages) Microchip Technology – 28/40/44-Pin Enhanced Flash Microcontrollers

PIC16F87XA
TABLE 4-3: PORTB FUNCTIONS
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
RB3/PGM⁽³⁾ bit 3
TTL
Input/output pin. Internal software programmable weak pull-up.
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.
TABLE 4-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
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
86h, 186h TRISB
PORTB Data Direction Register
81h, 181h OPTION_REG RBPU INTEDG T0CS T0SE PSA PS2 PS1
Legend: x = unknown, u = unchanged. Shaded cells are not used by PORTB.
RB0 xxxx xxxx uuuu uuuu
1111 1111 1111 1111
PS0 1111 1111 1111 1111
 2003 Microchip Technology Inc.
DS39582B-page 45