[time-nuts] Frequency subtraction with D-flip flops

[Poul-Henning Kamp]

In message <201306250015.r5P0FGEj007763 at mail6c40.carrierzone.com>, ed breya wri
tes:

>and trying to get my head around how a DFF can take the 
>difference between two frequencies.

Try first to think about what happens if you XOR the two
signals, then convince yourself that the DFF basically does
the same thing.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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