[time-nuts] Frequency division by 81

[Poul-Henning Kamp]

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Gilles Clement writes:

> Could you point me to a practical design example of a Pi divider ?

Look at Fig 2 in Enrico's paper:

> http://rubiola.org/pdf-articles/conference/2013-ifcs-Frequency-dividers.pdf

I would implement it so that the shiftregister is also the divider,
by making it twice the length and feed it back to itself.

In your case it would be a 18 stage shiftregister, where the first
9 stages initialize to zero, and the last 9 stages initialize to
one, with the output connected back to the input that will give you
a rotating pattern of 000000000111111111000000000111111111...

Only 9 of the stages should be driving resistors to the output.

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