µP rocessor Architectures To : Eng. Ahmad Hassan By: Group 18

Agenda  CISC architecture  RISC architecture  CISC vs RISC architecture  Von Neumann architecture  Harvard architecture  Von Neumann vs Harvard architecture

CISC architecture  Complex instruction set computer. Its actually a CPU designed to carry out many operations in a single in a single instruction. These can be loading from and to memory and performing mathematical operation etc.  Features Include:  Complex instruction  More number of addressing modes  Highly Pipelined  More data types in hardware

RISC architecture  Reduced instruction set Computer. It is a type of microprocessor that has been designed to carry out few instructions at the same time. As instructions are few it can be executed in a less amount of time. Another advantage is the use of fewer transistor reducing its cost.  Features include:  Demand less decoding  Uniform instruction set  Identical general purpose register  Simple addressing modes  Fewer data types in hardware

RISC Vs CISC architecture  Reduced Instruction Set Computer (RISC)  Compact, uniform instructions facilitate pipelining  More lines of code poor memory footprint  Allow effective compiler optimization  Complex Instruction Set Computer (CISC)  Many addressing modes and instructions; High code density.  Often require manual optimization of assembly code  for embedded systems.

Von Neumann architecture  The von Neumann Architecture is named after the mathematician and early computer scientist John von Neumann. von Neumann machines have shared signals and memory for code and data. Thus, the program can be easily modified by itself since it is stored in read-write memory

Harvard architecture  The name Harvard Architecture comes from the Harvard Mark I relay-based computer. The most obvious characteristic of the Harvard Architecture is that it has physically separate signals and storage for code and data memory. It is possible to access program memory and data memory simultaneously. Typically, code (or program) memory is read-only and data memory is read-write. Therefore, it is impossible for program contents to be modified by the program itself.

Von Neumann Vs Harvard architecture