16F887 - PORT pins interfere with each other when set high/low

[Ioannis]

Today I checked your code. Changed IESO in the configs and a bit in OSCCON which was read only.

Works just fine. Only thing is that LED on portb.7 is interfering with the programming and causing programming errors!

Besides that everything works just fine on the F887 chip at 8MHz.

#CONFIG
cfg1 = _INTRC_OSC_NOCLKOUT    ; INTOSCIO oscillator: I/O function on RA6/OSC2/CLKOUT pin, I/O function on RA7/OSC1/CLKIN
cfg1&= _WDT_ON                ; WDT enabled
cfg1&= _PWRTE_OFF             ; PWRT disabled
cfg1&= _MCLRE_OFF             ; RE3/MCLR pin function is digital input, MCLR internally tied to VDD
cfg1&= _CP_OFF                ; Program memory code protection is disabled
cfg1&= _CPD_OFF               ; Data memory code protection is disabled
cfg1&= _BOR_OFF               ; BOR disabled
cfg1&= _IESO_OFF               ; Internal/External Switchover mode is enabled
cfg1&= _FCMEN_ON              ; Fail-Safe Clock Monitor is enabled
cfg1&= _LVP_OFF               ; RB3 pin has digital I/O, HV on MCLR must be used for programming
cfg1&= _DEBUG_OFF             ; In-Circuit Debugger disabled, RB6/ICSPCLK and RB7/ICSPDAT are general purpose I/O pins
  __CONFIG _CONFIG1, cfg1


cfg2 = _BOR40V                ; Brown-out Reset set to 4.0V
cfg2&= _WRT_OFF               ; Write protection off
  __CONFIG _CONFIG2, cfg2
#endconfig

OSCCON=%01110001  'SET INTOSC TO 8MHZ

ANSEL = %00000000
ANSELH = %00000000 'disable ADC


TRISC=%00000000 'set PORTC as output all
TRISD=%00000000 'set PORTD as output all
TRISB=%00000000 'set PORTB as output all
TRISA=%00000001 'set PORTA 0 as input, others as output
TRISE=%00000000 'same here
BUZ var PORTB.7
BUTN var PORTA.0 



DEFINE OSC 8   'OSC SPEED
'turn off all digits


PORTA=0: PORTB=0: PORTC=0: PORTD=0 : PORTE=0 'turn off all outputs

CYCLER:
if BUTN=0 then
high BUZ
pause 100
low BUZ
pause 100
endif
goto CYCLER

end

I did a short video that shows a working state of the circuit on a PICdem2 Plus board. The PortA.0 is shorted by the yellow wire to ground.



Ioannis