Hummmmmm...
OK, one cannot have everything, especially for free :-)
I expect that with commercial core (or if I pay Jez the "vast amounts of cash" :-) I get it all.

However, I still feel, that this would not yield a complete hi-speed microcontroller. Usually, there is no real ROM (notabene FLASH) inside FPGAs. For >33MHz 1-clock operation, the trick is to (pre)fetch in parallel. That means to have attached a 16- or 32-bit wide FLASH (and memory interface) and the appropriate logic inside the (soft)core. To reduce penalty from missing pre-fetch when jumping, they also implement jump-caches, an another feature to be added. So the implementation seems to be much more complicated task than to write a functional core.

Still, my question, what is the advantage of a single-chip solution (either Zylogic or FPGA+softcore) over the two-chip '51+FPGA?

Jan Waclawek