SHIFTOUT MSB/LSBFIRST clarification


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  1. #1
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    Default Re: SHIFTOUT MSB/LSBFIRST clarification

    I am so sorry Richard:
    if the time flows from left to right, then the first bit sent should be on the right and not to the left of the scope !
    Where am I wrong please ?
    Bye

  2. #2
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    Default Re: SHIFTOUT MSB/LSBFIRST clarification

    which second was recorded first in time sequence ?

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    Default Re: SHIFTOUT MSB/LSBFIRST clarification

    slow your timbase right down , what direction does the dot travel

    the dot having writ moves on
    Last edited by richard; - 27th May 2021 at 10:41.
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    Default Re: SHIFTOUT MSB/LSBFIRST clarification

    the first bit sent out by the pic should be on the right ( 9 seconds old )
    The last bit sent by the pic should be on the left ( 0 seconds old )

    I am sorry for not understanding...
    thanks

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    Default Re: SHIFTOUT MSB/LSBFIRST clarification

    last try
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    Default Re: SHIFTOUT MSB/LSBFIRST clarification

    thanks again,
    I am sorry for not understand...
    If I slow down the scope time base the dot goes from left to right.
    So the first bit transmitted by the PIC is always to the right of the scope and the last transmitted by the PIC is shown to the left.
    Am I right ?
    Then the 9 seconds old bit is the first transmitted by the PIC.
    The 0 secs old bit is the last transmitted by the PIC.
    Is it right ?
    Thanks

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    Default Re: SHIFTOUT MSB/LSBFIRST clarification

    sorry: I did not tell that I am talking about the PIC output .
    Thanks

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    Default Re: SHIFTOUT MSB/LSBFIRST clarification

    completely wrong , the first bit is on the left
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  9. #9
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    Default Re: SHIFTOUT MSB/LSBFIRST clarification

    could you please check in the real situation:

    connect the PIC DATA output to scope ch_1
    connect the PIC clock output to scope ch_2 and set the trigger to this channel.
    Tranmit bin 00000011 ( dec 3 ) \8 selecting MSB FIRST. and insert a small delay in the main loop just for better scope triggering. My scope is a old style !

    What do you see on the scope ? 00000011 or 11000000 ?
    Or better: do you see "11" to the right side or to the left side of the scope ?

    Thanks for helping
    regards

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    Default Re: SHIFTOUT MSB/LSBFIRST clarification

    You will send 00000011.

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