Processors are electronic functional units. They consist of several functional units, each of which performs arithmetic, control and memory functions. The functions are triggered with control signals or commands and the results are transferred to another functional unit.
The functional units are the arithmetic unit( ALU), which executes the logical and mathematical functions, the registers for the short-term intermediate storage of the instructions and results, the control unit( CU) for the control of the instruction cycles, the instruction decoder( IDU) for the conversion of the machine instructions into single instructions, the memory manager( MMU) for the management of the working memory, the working memory( RAM) in which the results and intermediate results are stored and, last but not least, the various buses via which communication can take place with other components.
The term processor is often used synonymously with microprocessor or central processing unit( CPU). This is not quite correct, because the function blocks of a processor do not necessarily have to be located on an integrated circuit( IC). However, this is the case with the embodiments mentioned; all functional units are contained in the compact integrated circuit.
Processors differ in technology, computer architectures and circuit designs, in the bus widths of data bus, control bus and address bus, in the number of dual numbers to be processed in parallel, in the processing speed with which the arithmetic operations are executed and the results transferred to the main memory, in the memory sizes of the registers, the buffer, the caches, and the main memories, in their instruction structures, the machine codes, and in many other characteristics.