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I have a VHDL module that applies a shuffle algorithm to a 64 bit input and outputs the 64bit result.

I need to loop this output back through the module exactly 4 times, i was wondering if there was a way to do this asynchronously, or do i need a clock and counter to make this work?

Thanks.

Voltage Spike
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Loocid
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2 Answers2

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Realistically, you need a clock and counter, because you can't guarantee that all 64 bits will be available at the same time.

(Asynchronous design in FPGAs isn't impossible, but it's not supported by the tools and makes it extremely hard)

pjc50
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I don't see the problem of doing this asynchronously (combinatorially), by just connecting four such units serially. (But maybe I don't quiet understand the question? If you can't have more than one unit instantiated, this of course won't be possible.)

Carl
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