Find block diagram of any processor. Let’s try Zilog’s Z80 one. Here is the manual: https://www.zilog.com/docs/z80/um0080.pdf
Recreate all the block - registers, instruction decoder, alu, etc Wire it all together, and voila, you have a Z80 replica ;P
Nobody said it was easy :D
Here is a more detailed diagram: http://www.z80.info/gfx/fig214.gif
Understand and recreate all the parts, connect them, and that’s all. I’ve been working on my MOS8502 replica for a year and it is 95% done. Now working on interrupt handling.
