What is Address Bus in Microprocessor? [Computer Architecture]

An address bus acts as an interior mechanism that transfers the RAM position while the data is refined or any sort of command is being conducted. 

The address bus enables the CPU to direct the data address to the primary memory of the system and thereby allowing the real transfer of data to the microprocessor. 

If you want to know the practical usage of an address bus apart from these technical phrases, an address bus is basically a simple bus-based architecture that does the work of transferring data among computer components that hold the address of the hardware present on the RAM (Random Access Memory) and the data address is saved in the binary digit that allows the bus to direct communication to the RAM.

The wires and connection channels present in the bus tells about the maximum capacity of memory that could be accessed by the CPU processor. Each wired channel has the capacity of carrying a single or 1-bit data address. 

The IBM PCs back in 1981 had only the limit of 1-Megabyte RAM capacity as the address bus had only support of twenty channels with a total of only twenty-bit data transfer capability.   

An address bus is taken under use directly by the CPU for the purpose of accessing the RAM which is given the grant access from the direct access memory that allows the devices to easily find and figure the physical address for the purpose of communicating the read and write commands.

Every single address bus is read and written through the microprocessor and direct memory access of the system in bits form. 

A pc with an actual 32-bit address bus can without delay address with 4GB of primary memory, even as one with 36 bits can deal with 64GB.

An Address bus is an integral part of the gadget bus architecture, which changed into advanced to lower fees and improved modular amalgamation. However, maximum present-day computer systems use numerous buses for particular tasks.

A PC carries a system bus, which makes a communicative interface with the fundamental units of a PC. It follows 3 basic principle features, in which the address bus is one, at the side of the data bus, and the management bus. 

The measurement of an address bus is done through the capacity of RAM a computer system is holding, a  computer system with the support of a 32-bit address bus can easily support a 4 GB of RAM memory. However, the latest and current-gen PCs are given the support of a 64-bit address bus along with an OS that can bear 16-exbibytes of the memory address. 

Now, you need to understanding that what exactly is this “system bus”, as this term is repeating quite frequently in this article.

A system is a simple channel or course that is constituted of connecting copper wires that carry the information among different components of the computer including the CPU and the RAM, that are present on the motherboard. The bus offers a way for those data informatics and controlling mediums for movement by the major components of the PC system.    

The work of a system bus is to combine the usage or the 3 basic functions that the main bus performs, and those 3 main buses are the data bus, address bus, and the control bus and each of these mentioned buses have their special and separate functions.  

The main function of a control bus is to include the management, timing, and coordination alerts to control the diverse features throughout the system.

The address bus is taken into use for the purpose of specifying memory location so that the data can be transferred easily.

The data bus is the most different from the above two buses as it is a bidirectional bus that has multiple pathways, it takes the real data among the processor of the CPU and other the memory stages and external peripherals.