[sdiy] Digital noise sources

[Scott Gravenhorst]

xyzzy at sysabend.org wrote:
>Something else I've been pondering.
>
>I noticed in Tom Wiltshire's noise generator PIC that he preloads the shift
>registers with some random data.  I'm curious about something though...  In
>a "normal" logic based noise source, are we depending on the power-on state
>of the shift register to be random, or are we just loading it from 0 with
>the pattern generated from the XOR's?

I've done it by seeding with some value not equal to all ones and also with a seed of
zero.  I use LFSRs for audio noise, not pseudorandom sequences at low rates of speed. 
For my use, it doesn't seem to matter, it sounds like noise.  There is only one "evil"
value in a max length LFSR, so avoid that and you're good - every other value will come
up eventually anyway, so no matter what your seed is, it's always just one number in a
sequence of many.


-- ScottG

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-- Scott Gravenhorst
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