NOTES
ON
8085 MICROPROCESSOR
, Introduction
Microprocessor is a Central Processing Unit (CPU) etched on a
single chip. A single Integrated Circuit (IC) has all the
functional components of a CPU namely Arithmetic Logic Unit
(ALU), Control Unit and registers. The 8085 microprocessor is
an 8-bit processor that includes on its chip most of the logic
circuitry for performing computing tasks and for
communicating with peripherals.
What about micro? • Micro is a new addition. – In the late
1960’s, processors were built using discrete elements. • These
devices performed the required operation, but were too large
and too slow. – In the early 1970’s the microchip was invented.
All of the components that made up the processor were now
placed on a single piece of silicon. The size became several
thousand times smaller and the speed became several hundred
times faster. The “Micro”Processor was born.
,Definition of the Microprocessor:
The microprocessor is a programmable
device that takes in numbers, performs on
them arithmetic or logical operations
according to the program stored in memory
and then produces other numbers as a result.
, Programmable device: The microprocessor can perform different
sets of operations on the data it receives depending on the sequence
of instructions supplied in the given program. By changing the
program, the microprocessor manipulates the data in different
ways. –
Instructions: Each microprocessor is designed to execute a specific
group of operations. This group of operations is called an
instruction set. This instruction set defines what the microprocessor
can and cannot do.
Takes in: The data that the microprocessor manipulates must come
from somewhere. • It comes from what is called “input devices”. •
These are devices that bring data into the system from the outside
world. • These represent devices such as a keyboard, a mouse,
switches, and the like.
Numbers: The microprocessor has a very narrow view on life. It
only understands binary numbers. A binary digit is called a bit
(which comes from binary digit). The microprocessor recognizes
and processes a group of bits together. This group of bits is called a
“word”. The number of bits in a Microprocessor’s word, is a
measure of its “abilities”.
ON
8085 MICROPROCESSOR
, Introduction
Microprocessor is a Central Processing Unit (CPU) etched on a
single chip. A single Integrated Circuit (IC) has all the
functional components of a CPU namely Arithmetic Logic Unit
(ALU), Control Unit and registers. The 8085 microprocessor is
an 8-bit processor that includes on its chip most of the logic
circuitry for performing computing tasks and for
communicating with peripherals.
What about micro? • Micro is a new addition. – In the late
1960’s, processors were built using discrete elements. • These
devices performed the required operation, but were too large
and too slow. – In the early 1970’s the microchip was invented.
All of the components that made up the processor were now
placed on a single piece of silicon. The size became several
thousand times smaller and the speed became several hundred
times faster. The “Micro”Processor was born.
,Definition of the Microprocessor:
The microprocessor is a programmable
device that takes in numbers, performs on
them arithmetic or logical operations
according to the program stored in memory
and then produces other numbers as a result.
, Programmable device: The microprocessor can perform different
sets of operations on the data it receives depending on the sequence
of instructions supplied in the given program. By changing the
program, the microprocessor manipulates the data in different
ways. –
Instructions: Each microprocessor is designed to execute a specific
group of operations. This group of operations is called an
instruction set. This instruction set defines what the microprocessor
can and cannot do.
Takes in: The data that the microprocessor manipulates must come
from somewhere. • It comes from what is called “input devices”. •
These are devices that bring data into the system from the outside
world. • These represent devices such as a keyboard, a mouse,
switches, and the like.
Numbers: The microprocessor has a very narrow view on life. It
only understands binary numbers. A binary digit is called a bit
(which comes from binary digit). The microprocessor recognizes
and processes a group of bits together. This group of bits is called a
“word”. The number of bits in a Microprocessor’s word, is a
measure of its “abilities”.
