ABSTRACT
A microprocessor system can be described at a number of different levels of complexity. All microprocessor systems contain a central processing unit (CPU), program and data memory and input and output devices. The level and power specifications of the interfacing signals of the microprocessor system are frequently incompatible with the signal specifications of the devices which are to be interfaced to it. The concepts of address and data are fundamental to the operation of a stored program computer and form a feature of all microprocessors and computers. The memory will consist of a number of memory locations capable of storing data written to them by the CPU over the data bus. The operation of the CPU must be considered in order to gain an understanding of how it performs the operations defined by the instructions that it reads from memory. The CPU is responsible for the control of the address, data and control buses.
