Tim Kerby <PICLIST@MITVMA.MIT.EDU> wrote:

> I am about to reach a deadline on a project at school (for the
> engineering scheme scotland) and my random no generation isnt
> working.  It must take the tmr0 or any internal part of the chip as
> i dont have lines to spare and give out a number between 1 and 12
> (inclusive).

Tim:

To select a TMR0-based number between 1 and 12, inclusive, do
something like this:

    LOOP:       MOVF    TMR0,W
            ANDLW   00001111B
            ADDLW   -12
            BC      LOOP
            ADDLW   13

After executing the fragment above, W will contain a number in the
range [1-12].  This is just about the worst possible way to get
random numbers -- the distribution is VERY skewed toward the low end
of the range, and the whole thing's based on a deterministic timer --
but it's quick (so long as you haven't enabled a large TMR0
prescaler), easy, and doesn't require any additional file registers.

-Andy

=== Andrew Warren - fastfwd@ix.netcom.com                 ===
=== Fast Forward Engineering - Vista, California          ===
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