Re: CPU design

radarman wrote:
Maybe you are right and the core and programs are smaller with Forth, I'll
think about it. Really useful is that it is simple to write an interactive
read-eval-print loop in Forth (like in Lisp), so that you can program and
debug a system over RS232.



Simpler solution - have the microcode FSM push the flags to the stack.
It's a simple alteration, and saves a lot of heartache. I have
contemplated even pushing the entire context to the stack, since I can
burst write from the FSM a lot faster than I can with individual
PSH/POP instructions, but I figure that would be overkill.

For someone doing a fully custom/own assembler/compiler :

The tiniest CPUs do not need a stack, and interupts do not need to be
re-entrant, so a faster context switch is to re-map the Registers, Flags (and even PC ? ) onto a different area in BRAM.
You can share this resource by INTs re-map top-down, and calls re-map
bottom up - with a hardware trap when they collide :)

-jg

.

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