PIC16F8X_13 Datasheet, PDF (24/128 Pages) Microchip Technology – 18-pin Flash/EEPROM 8-Bit Microcontrollers

PIC16F8X
EXAMPLE 5-1: INITIALIZING PORTB
CLRF PORTB
; Initialize PORTB by
; setting output
; data latches
BSF STATUS, RP0 ; Select Bank 1
MOVLW 0xCF
; Value used to
; initialize data
; direction
MOVWF TRISB
; Set RB<3:0> as inputs
; RB<5:4> as outputs
; RB<7:6> as inputs
TABLE 5-3 PORTB FUNCTIONS
Name
Bit Buffer Type
I/O Consistency 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
bit3
TTL
Input/output pin. 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
bit6
TTL/ST⁽²⁾ Input/output pin (with interrupt on change). Internal software programmable
weak pull-up. Serial programming clock.
RB7
bit7
TTL/ST⁽²⁾ Input/output pin (with interrupt on change). Internal software programmable
weak pull-up. Serial programming data.
Legend: TTL = TTL input, ST = Schmitt Trigger.
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.
TABLE 5-4 SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
Address Name
Bit 7 Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
06h
PORTB
86h
TRISB
RB7
RB6
RB5
TRISB7 TRISB6 TRISB5
RB4
TRISB4
RB3
RB2
TRISB3 TRISB2
81h
OPTION_
REG
RBPU INTEDG T0CS
T0SE
PSA
PS2
Legend: x = unknown, u = unchanged. Shaded cells are not used by PORTB.
Bit 1
Bit 0
RB1 RB0/INT
TRISB1 TRISB0
PS1
PS0
Value on
Power-on
Reset
xxxx xxxx
1111 1111
1111 1111
Value on all
other resets
uuuu uuuu
1111 1111
1111 1111
DS30430D-page 24
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