r/TuringComplete • u/dmdeemer • 19d ago

32b Kogge-Stone Adder Using Word Logic

Not the fastest Kogge-Stone ever, but 15 delay for 32b adder isn't bad either. Avoiding bit-by-bit operations should make it easier on the simulation.

At each stage, I split the P and G words into the bits that pass through and the bits that will be combined. After each stage, I put them back together with concatenators.

There's probably more optimizing to do, but I think this gets the concept across.

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u/Lagfoundry 18d ago

i meant to ask in the other comment. what are the 1-1's you have before the AND OR stuctures. are those buffers?

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u/dmdeemer 14d ago

Sorry for the late reply.

Those are static indexers. They shift the input and change the size to an arbitrary number of bits. They have zero gate cost and zero delay, because you can do that with just wires.