Simple Enough Processor : From Scratch Elaborated Simulated Educational CPU

This paper describes a new simplistic academic CPU, designed to be constructed step-by-step by the student using a logic simulator called Logisim. An effort is made to close the gap with the real-world processors by supplying their major capabilities, like multiple programmable registers, multiple addressing modes, shift instruction, comparison and logic instructions, multiple branch and jump instructions, the stack and subroutine mechanisms, flags indicators, input/output mechanism, a proper assembler... etc. The processor would comprise 21 instructions and 4 addressing modes, with the capability using the flexible control unit sequencer, to easily add more customizable instructions.