Specifications

Computer Architecture and Maintenance (G-Scheme-2014)
System bus
It is a group of conductors. It is used to transfer information (electrical signal )
between two units. It consists of Data Bus, Address Bus and Control Bus.
Functions of Buses
The functions of buses can be summarized as below:
1. Data sharing - All types of buses found on a computer must be able to transfer
data between the computer peripherals connected to it.
The data is transferred in in either serial or parallel, which allows the exchange of
1, 2, 4 or even 8 bytes of data at a time. (A byte is a group of 8 bits). Buses are
classified depending on how many bits they can move at the same time, which
means that we have 8-bit, 16-bit, 32-bit or even 64-bit buses.
2. Addressing - A bus has address lines, which match those of the processor. This
allows data to be sent to or from specific memory locations.
3. Power - A bus supplies power to various peripherals that are connected to it.
4. Timing - The bus provides a system clock signal to synchronize the
peripherals attached to it with the rest of the system.
Internal Registers (Internal Data Bus)
The size of the internal registers indicates how much information the processor
can operate on at one time and how it moves data around internally within the chip.
This is sometimes also referred to as the internal data bus. A register is a holding cell
within the processor; for example, the processor can add numbers in two different
registers, storing the result in a third register. The register size determines the size of
data on which the processor can operate. The register size also describes the type of
software or commands and instructions a chip can run. That is, processors with 32-bit
internal registers can run 32-bit instructions that are processing 32-bit chunks of data,
but processors with 16-bit registers can’t. Processors from the 386 to the Pentium 4 use
32-bit internal registers and can run essentially the same 32-bit OSs and software. The
Core 2, Athlon 64, and newer processors have both 32-bit and 64-bit internal registers,
which can run existing 32-bit OSs and applications as well as newer 64-bit versions.
A register is a memory location within the CPU itself, designed to be quickly
accessed for purposes of fast data retrieval. Processors normally contain a register
array, which houses many such registers. These contain instructions, data and other
values that may need to be quickly accessed during the execution of a program.
Prepared By – Prof. Manoj.kavedia (9860174297 – 9324258878 ) (www.kavediasir.yolasite.com)
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