[F4HDK]

Maybe I have not understood in details what you mean... but my A2Z CPU has no internal (hardware) stack pointer, unlike the 8051. The only available addressing mode is "direct addressing". Of course, you can emulate indirect addressing modes, and you can emulate 32 bits manipulations... But it will be not optimal at all (=very slow compared to programs using only direct addressing). Here, on A2Z, the compiler matches the simplicit of the CPU architecture, it is the same philosophy : only static allocation for variables. If I wanted a custom CPU compatible with a C compiler and with Linux, the CPU would have been totally different.