Ostensibly, it should execute 805x code and work, as viewed from the outside, just like an 805x, with the exception of the "standard" peripherals, unless they happen to be there. This is a configurable device, not a fixed one. There'll be a datasheet for each peripheral block, and one for the CPU. The two just won't be wedded to the oscillator and one another in the same way as they've been on the 805x. It's unlikely this "thing" will compete with standard off-the-shelf MCU's, simply because of cost. However, if one has to build one or more custom peripherals, it will be as inexpensive to use the FPGA that contains the custom logic to contain the MCU and memory as well. For that reason, I'm exploring just how that MCU can best be architected in FPGA.

I see, Erik, you're like me ... you don't like change.

However, what I want to do is to fix the things that have, for 30 years, hobbled this otherwise pretty decent architecture. I don't see the benefit it leaving SFR's for hardware that's not there in place, as it deprives me of the space to support something I am using.

You're right of course, it will be a far cry from the "real" 805x, though it should, if I get my way, execute code generated with 805x tools as though it were the "real McCoy."

RE