p16f877 Microchip Technology Inc., p16f877 Datasheet - Page 34

• Manufacturer Part Number: p16f877
• Description: 28/40-pin 8-bit Cmos Flash Microcontrollers
• Manufacturer: Microchip Technology Inc.

PIC16F87X
TABLE 3-3:
TABLE 3-4:
DS30292C-page 32
RB0/INT
RB1
RB2
RB3/PGM
RB4
RB5
RB6/PGC
RB7/PGD
Legend: TTL = TTL input, ST = Schmitt Trigger input
Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt.
06h, 106h
86h, 186h
81h, 181h
Legend: x = unknown, u = unchanged. Shaded cells are not used by PORTB.
Address
Name
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.
(3)
PORTB
TRISB
OPTION_REG RBPU
Bit#
bit0
bit1
bit2
bit3
bit4
bit5
bit6
bit7
Name
SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
PORTB FUNCTIONS
TTL/ST
TTL/ST
TTL/ST
Buffer
PORTB Data Direction Register
TTL
TTL
TTL
TTL
TTL
Bit 7
RB7
(1)
(2)
(2)
INTEDG T0CS T0SE PSA
Bit 6
RB6
Input/output pin or external interrupt input. Internal software
programmable weak pull-up.
Input/output pin. Internal software programmable weak pull-up.
Input/output pin. Internal software programmable weak pull-up.
Input/output pin or programming pin in LVP mode. Internal software
programmable weak pull-up.
Input/output pin (with interrupt-on-change). Internal software programmable
weak pull-up.
Input/output pin (with interrupt-on-change). Internal software programmable
weak pull-up.
Input/output pin (with interrupt-on-change) or In-Circuit Debugger pin.
Internal software programmable weak pull-up. Serial programming clock.
Input/output pin (with interrupt-on-change) or In-Circuit Debugger pin.
Internal software programmable weak pull-up. Serial programming data.
Bit 5
RB5
Bit 4
RB4
Bit 3 Bit 2 Bit 1 Bit 0
RB3
RB2
PS2
Function
RB1
PS1
RB0
PS0
2001 Microchip Technology Inc.
xxxx xxxx uuuu uuuu
1111 1111 1111 1111
1111 1111 1111 1111
Value on:
POR,
BOR
Value on
RESETS
all other