SIMPLE LOGIC OF MICROPROCESSOR

A microprocessor performs a collection of machine instructions that the processor what to say. Based on the instructions, a microprocessor does three basic things:

* Using the ALU (Arithmetic / Logic Unit), a microprocessor can perform mathematical operations like addition, subtraction, multiplication and division. Modern microprocessors contain complete floating point processors that can perform extremely sophisticated operations on large floating point numbers.
* A microprocessor can move data from one memory location to another.
* A microprocessor can make decisions and jump to a new set of instructions based on those decisions.

It can be very sophisticated things that a microprocessor does, but those are its three basic activities. The following diagram shows an extremely simple microprocessor that can do three things:
This is about as simple as a microprocessor gets. This microprocessor has:

* An address bus (which can be 8, 16 or 32 bits wide) that sends an address in memory
* A data bus (which can be 8, 16 or 32 bits wide) that the data in memory can send or receive data from memory
* A RD (read) and WR (write) line to memory, whether he wants to establish whether the recipient site to get say
* A clock line that lets a clock pulse sequence the processor
* A reset line that the program.