Microprocessor

A microprocessor is a CPU molded in single IC (Integrated circuit) package. Microprocessor posses the characteristics of small size and low
cost. The list of some of uP are 8080, 8085, 8086, 8088 chip No.
Microprocessor is used to denote that part of the system which performs the basic functions to execute instructions and to process data as
specified by a program.

This part is usually called CPU.

microprocessor 8085 

A microprocessor together with memory and input/output capability is called micro computer.
The CPU of a large computer consist of a number of microprocessors. Each microprocessor does the specified task within the CPU. It will be working
in parallel.

1. Data bus :
It is used to send or receive data to and from different devices. It is bidirectional device.

2. Address bus :
It is used to transfer the address bite of a memory location or a peripheral device.It is unidirectional device

3. ALU (Arithmetic logic unit):
It performs various arithmetic and logical operations like addition, subtraction, multiplication, AND, OR, less than, greater than etc.

4. Control bus:
It is used to transfer the Control signals

5. Accumulator:
It store one of the operands for ALU operation. The final result of the operation is also stored in the accumulator.

6.Temporary register:
It also store the other operand along with the accumulator needed for ALU operation. For ALU operation, one operand is stored in accumulator and another in
temporary resister.

7. General purpose registers:
They are basically used to store information temporarily while program is executing. The programmer can also use them.

8. Instruction register and decoder :
An instruction register store the instruction being fetched from memory.
The decoder, decodes the instruction available in the instruction register and supply it to the control unit.

9. Program counter:
It is a register used to store the address of the instruction to be read from memory after the current instruction is executed. It is used by the microprocessor for
automatic sequencing of instruction.

10. Stack-pointer:
Stack is a sequence of memory locations in RAM reserved for some predefined specific purpose. Stack-pointer is a register
at stores the address of a location in the stack.

11. Flags:
They are flip-flops that are set or reset to represent the data conditions of the result obtained after the last ALU operation.

12. Control unit:
lt is used to produce proper control signals that control all the operations performed by various parts of a microprocessor and other components of a digital system.It perform all the operation synchronously.