hw multiplier for Cyclone

Ya there's no problem with implementing the multiplier asynchronously. I'm not too familar with the DSP blocks in cyclone, but in stratix you get input/output registers within the block so they don't require extra LE's in case you want to make the block synchronized.

I'm assuming the divider you used is the megawizard one as well with the divisor and dividend in, and quotient and remainder out. I was using that in a design in the mean time before I made my own synchronized divider (wanted something around 1/5th the size in LEs). Watch out for the answers coming out of that block. The have two modes....... I'd tell you what they are but still haven't installed quartus because I've been busy around the house. But basically one mode gets you a proper answer (remainder always positive), and the other mode gives you sign dependent remainders (but can give you magnitudes that you don't normally expect. If you were unaward of this I would throw it into a simulation by itself and try different values into it to make sure you don't run into bugs later down the road (because that divider wouldn't be the first place to look I'd imagine). Or check the documentation for lpm_divide or lpm_divider (whatever it's called) in quartus and they show near the bottom what kind of results to expect from the different modes (keep and eye on the remainder or you might miss the difference between the two modes)

Cheers.