Another simple program misbehaving

I'm having problems with the below code. It is written for a 16F1829. It is a stripped down version of what I want. I am guesssing the problem is with not disabling something analog or the pull ups not working right. I have tried adding 4.7k external pull up resistors on both B4 and B5 to 5 volts as well. This is the first time I have tried using this part.

Code:

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asm
    __CONFIG    _CONFIG1, _FOSC_INTOSC & _WDTE_ON & _PWRTE_OFF & _MCLRE_OFF & _IESO_OFF
    __CONFIG    _CONFIG2, _PLLEN_ON & _LVP_OFF & _STVREN_OFF
endasm
       
Clear
define OSC 32

OSCCON = %11110000              '32 MHz internal

ANSELA = 0              'set porta to digital
ANSELB = 0
ANSELC = 0

OPTION_REG.7 = 0    'enable weak pullups
WPUB = %00110000
INLVLB = 0

CM1CON0.7 = 0        'disable comparator
CM2CON0.7 = 0

TRISA = %011000        '0-2 tx pins
TRISB = %11001111      'red and green
TRISC = %11111111      '

Red        var PORTB.5
Green      var PORTB.4

PORTA = %000111
PORTB = 0
PORTC = 0

Pause 1000

mainloop:

    green = 1
    red = 0
    pause 1000
    green = 0
    red = 1
    pause 1000
goto mainloop

end

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The basic program toggles a red and green line, one high and one low. If I comment out both green or both red lines the program behaves exactly as desired, with the un-commented line going on and off. When both red and green are in the code then the green light remains on and the red light will toggle. I have tried to look for every register I can find in the datasheet that may have anything to to with this, but no luck. I have also pulled the legs up from the circuit and checked with a volt meter just to make sure there aren't any physical problems with the board. I have also use multiple chips.

thanks in advance for the help.

What happen if you change your High & red definition with

Code:

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Red        var LATB.5
Green      var LATB.4

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Quote:

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Originally Posted by mister_e

What happen if you change your High & red definition with

Code:

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Red        var LATB.5
Green      var LATB.4

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...magically all my problems seem to go away now. I've never needed to use LATX before. Maybe you can educate me a little on why I needed to this time. The datasheet seems to imply that writing to the latch is just a more direct way of writing to the port, but maybe I'm not catching the nuance.

Thanks
David

You should also do it with PIC18 and with all PIC having LATx register. This is to avoid the R-M-W issue. The datasheet explain it, like you said. For further details you may want to have a look at this document

http://www.cornerstonerobotics.org/c...mw_problem.pdf