Dear All,

I just begin to do programming on PIC. I used pic16f84 as
my target MPU. Plan to do output of PORTB '11111111', all
ports are logic high.

But what I found output was Bit0, 2, 4, 6 are "1", and Bit 1,
3, 5, 7 are low. I inited portB to be all outputs, but it
still giving me output of '01010101', why? I tried on portA,
but it still gave '10101', funny output!


Following is my simple source code:-

--------


LIST p=16F84        ; Target PIC, PIC16F84
#include "P16F84.INC"     ; include P16F84 header file

PORTA  equ 05
PORTB  equ 06
count1 equ 0C
count2 equ 0D

 org 0         ; origin 0

init
 movlw 0
 tris PORTB        ; set PORT B, [B0 - B7] are inputs movlw 0

start
 movlw 255
 movwf PORTA
 call wait
 movlw 0
 movwf PORTA
 call wait
 goto start

wait
 movlw .200              ; load count1 with decimal 200
 movwf count1
d1
 movlw .200        ; load count2 with decimal 200
 movwf count2

d2
 decfsz count2, 1     ; decrement and skip next line if zero
 goto d2         ; if not zero
 decfsz count1      ; decrement count1 if count2 is zero
 goto  d1         ; do inside loop again if count2 nz
 return

END

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