Registers

3. Microprocessor

A microprocessor makes extensive use of hardware registers built into the silicon chip itself. The diagram below shows some of the internal parts of a typical CPU.

Every item shown in the diagram is a register, each of which has a specific role to play.

For example, the two registers called MDR and MAR are acting as the interface between the CPU and RAM. The Program Counter is pointing to the location of the next instruction in RAM to be fetched. There are also a number of general purpose registers for data handling.

This is what it looks like as registers get updated by the running software - an update happens on every cycle of the CPU clock

Microprocessor are present in many types of equipment. For example a digital instrument such as a data logger or a counter will have one.

The registers within the CPU will be used to handle the Input-Output functions of the instrument as well as processing and storing data.