International Journal of Computer Technology and Electronics Engineering
From the architecture point of view, the microprocessor chips can be classified into two categories: Complex Instruction Set Computers (CISC) and Reduce Instruction Set Computers (RISC). In either case, the objective is to improve system performance. The debates between these two architectures made this research area very interesting, challenging, and sometimes confusing. CISC (Complex Instruction Set Computer) computers are based on a complex instruction set in which instructions are executed by microcode. Microcode allows developers to change hardware designs and still maintain backward compatibility with instructions for earlier computers by changing only the microcode, thus make a complex instruction set possible and flexible.