ISA
A Simple RISC...
Some ideas for a simple RISC processor although unlikely to ever be made, do have possible application. To make it easy a 16 bit wide instruction and 16 general registers 32 bit wide make most sense.
Hiding the link register ln has good security implications so it is always
implicit. Also the pc can be implicit too. So here goes. It’s not as though
the return stack isn’t heavily cached, and doesn’t need writeback of anything
below the stack pointer line.