Help with FPGA selection for 32-bit CPU core with accessible RAM and its backup at power-off
I'm in FPGAs still beginner and how time goes I did not progress for problems with FPGA selection.
What I need:
FPGA able to run 32-bit CPU custom core with whole accessible memory range - what is 4GB, at least 44-pin IO, flash memory and for example eMMC to backup RAM at power-off.
I want to extend 8-bit computer Commodore 128 with external 32-bit CPU and its RAM. In flash I want to store anything similar like BIOS for user selection. 8-bit C128 computer req's not and maybe never will 4GB RAM, but I want to use it like internal disk for storing files with loading time as fast as possible. In RAM it is near ATM. At power-off I want to store whole computer state and backup FPGA-RAM to anything which requires no power. It looks that eMMC is good solution, but don't know how fast it is. I need only bit more than 4GB for storing computer state incl. internal RAM and 4GB RAM of FPGA. 8-bit computers have no anything like shutting down or so and users awaiting it not, so I need to backup it near in second or at powering off leave bit time power for FPGA RAM backup - I don't know if is any battery possible - is enough CMOS battery? If, exist FPGA featuring else one thing - RTC?
Maybe you're looking at me like on crazy man for this extension. But this 8-bit computer has also 16-bit CPU extension with 16MB RAM - and I want to create successor offering else bit more. C128 has x65 CPU MOS 8502 with 128K RAM and mentioned extension has 65k WDC 65816 CPU with 16MB RAM - my extension can have 65k WDC 65832 CPU with 4GB RAM with selectable size of RAM between disk storage. x65 and 65k architecture is near the same - 65k has subset of opcodes of x65 excluding illegal opcodes, off course this is only this part of architecture.
I hope anybody of you can help me to find FPGA allowing it and I will do it. Thank you for everything, help, reply, comments, words...