There are many parts that make up the processor including the ALU, Registers and the control unit. I will be explaining all of them in this post and will talk about busses.
ALU (Arithmetic and Logic Unit): In some computer processors, the ALU is divided into two distinct parts, the AU and the LU. The AU performs the calculations and the LU performs the logical operations e.g. AND/NOT. It is the final processing performed by the processor. After the information has been processed by the ALU, it is sent to the computer memory.
Registers: These are temporary storage locations. Similar to memory but are much faster. All data must be represented in a register before it can be processed. The register can contain the address of a memory location where data is stored rather than the actual data itself.
Control Unit: A control unit works by gathering input through a series of commands it receives from instructions in a running programs and then outputs those commands into control signals that the computer and other hardware attached to the computer carry out. It controls all other parts of the processor making sure that all instructions are carried out in the correct order during the correct time. To summarise the control, unit basically manages the fetching, decoding and executing of instructions.
Internal Busses: These are used to transmit information. They are often referred to a local bus but they are meant to connect to local devices.
Address Bus: Carries the address from the processor to the main memory. This tells the main memory which location will be read or used to store information. A wire on the bus carries one piece of information at a time. The more wires the more memory locations. Each memory location is represented by a unique binary address.
Data Bus: Used to transfer data between the CPU (Central Processing Unit) and main memory.
Control bus: Each wire on the bus has it’s own function which is activated indepdently.
Read line – this informs the memory that the data is sent from the processor from a certain memory location.
Write line – informs the memory that data is to be stored in a particular memory location.