PIC16C712T-04/SO View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16C712T-04/SO

8-Bit CMOS Microcontrollers with A/D Converter and Capture/Compare/PWM

Microchip Technology 

PIC16C712/716

3.2 PORTB and the TRISB Register

PORTB is an 8-bit wide bi-directional port. The corre-

sponding data direction register is TRISB. Setting a

TRISB bit (=1) will make the corresponding PORTB pin

an input, (i.e., put the corresponding output driver in a

hi-impedance mode). Clearing a TRISB bit (=0) will

make the corresponding PORTB pin an output, (i.e.,

put the contents of the output latch on the selected pin).

EXAMPLE 3-1: INITIALIZING PORTB

BCF STATUS, RP0 ;

CLRF PORTB

; Initialize PORTB by

; clearing 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

FIGURE 3-3: BLOCK DIAGRAM OF RB0 PIN

RBPU(1)

DATA BUS

WR PORT

WR TRIS

Data Latch

DQ

CK

TRIS Latch

DQ

CK

Each of the PORTB pins has a weak internal pull-up. A

single control bit can turn on all the pull-ups. This is per-

formed by clearing bit RBPU (OPTION_REG<7>). The

weak pull-up is automatically turned off when the port

pin is configured as an output. The pull-ups are dis-

abled on a Power-on Reset.

VDD

P

weak

pull-up

VDD

TTL

Input

Buffer

I/O

pin

VSS

RD TRIS

RD PORT

QD

EN

RB0/INT

Schmitt Trigger

Buffer

RD PORT

Note 1: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (OPTION_REG<7>).

© 1999 Microchip Technology Inc.

Preliminary

DS41106A-page 23

Share Link: