µProcessor
Architectures
By: Group 18
To :
Eng. Ahmad Hassan
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