Adjusting PWM frequency


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  1. #5
    Join Date
    Aug 2006
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    Default 249?

    Bruce,

    Why should it be loaded with 249?

    If I calculate the possible resolution with this given formula, it makes exactly 10 bits with PR2 set to 255 "+1".
    <img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=2417&stc=1&d=120549250 2">
    I have to admit that the PWM calculation is still a mystery to me; I only roughtly understand the different parameters involved.

    But this is exactly why I would like to understand where this value "249" comes from.

    Tosc is a fourth of one microsecond (using the 4MHz XTal), isnt 'it?
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    Roger

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