Processor bus is defined as the bus that provides the path for communication between the main buses send the central processing unit. It also serves as the communication medium between the central processing units and other chipboard devices in the CPU. Processors buses are used in every central processing unit and these pathways make the central processing unit able to communicate with rest of the main components of the motherboards and external memory devices such as external cache. Size of the processor bus varies with the type of the processor and CPU brand. But depends on the length of the data word. For instance, the 80486 chip make use of 32 bits words. These kind of processor bus use 32 lines for the address and 32 lines for data transfer also. It varies with the manufacturer of the computer or processor also such as Pentium processors have 64 bits of word length. Form which 32 are dedicated for the address and rest for the data. One of the key features of the processor data bus is the maximum rate of data transfer through the motherboard clock ticks.
Standard architecture of the Bus
Before the evolution of the advancement processing technologies .there were only eight line s for the data transfer and for the address the lines were just 20 .with the passage of time this length became insufficient for delivering the large amount of data from one destination to another to handle this increased capacity buses with 16 bit were introduced. to make it compatible within existing boards another 36 pins were added to the connectors on every circuit on the board .This resulted in increased number of lines four for data and four lines form the address. For very channel concerned.
ISA Industry Standard Architectures have developed the local buses with the expanded memory which are compatible to almost every version of the processors and can be used with eth every type of computer. one of the most common type of the bus is the VESA bus that come along with the video graphic adapter for high speed video Processing Video Electronics Standards Association. One of the advantages of the VESA busses is that they can be connected directly to the video processor.
Types of processor buses
There are three common and most famous processor buses that area integrated with every mother board for different purposes.
Memory buses are designed for transferring the digital data and signal between random access memory and central processing units. these kind of buses are some how recognized as processor bus and can be configured to provide the dedicated setting on chip to control the memory .i n different versions of the computer systems motherboard with the clock rate of 16 mega hertz is provide that is controlled by the memory chip in order to make controller bus more efficient.
Address buses are another processor buses that are responsible for sending the next location address where data has to be delivered. The high standard address buses in 486 processor and all Pentium version is 32 bits.
Input /Output Buses
These types of processor buses are responsible for sending input and output signals between central rpo9cesisng unit and other external peripheral devices. These buses are directly compatible to the micro computer ship architecture and use the system known as S 100.I/O buses have 62 lines and every single line is connected to the connector pins. Eight of the data lines are responsible for proving input output relevant data in the microprocessor by Intel 8088 versions.