OPTION_REG.7=0…… Or does it ?


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  1. #1
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    Question OPTION_REG.7=0…… Or does it ?

    Hi all

    Am using a 16f818 in a simple program …all is working BUT :-

    OPTION_REG.7=0 ' Enables all pull-ups on PORTB

    Question is What happens if only PORTB 0-3 are inputs and 4-7 are outputs….I thought I had seen a way of enabling . disabling some pins if this was the case…..

    OR Does telling PBP that pin 4-7 are outputs do it for me ???

    My program is working fine….. Just wondering !

    Thank you for reading

    Andy
    Last edited by Archangel; - 12th March 2015 at 23:18.

  2. #2
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    Default Re: OPTION_REG.7=0…… Or does it ?

    0 = PORTB pull-ups are enabled by individual port latch values - inputs only get pullups

    BTW OPTION_REG.7=0 Decimal point got lost in post, I will fix in your post, check your code
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  3. #3

    Default Re: OPTION_REG.7=0…… Or does it ?

    Selecting a gpio as output automatically disables the weak pull-up. Several peripherals do the same.

    George

  4. #4
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    Default Re: OPTION_REG.7=0…… Or does it ?

    Quote Originally Posted by towlerg View Post
    Selecting a gpio as output automatically disables the weak pull-up. Several peripherals do the same.

    George
    Is what I thought….

    Just needed to confirm…. Thank you

    Andy

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