The Motherboard Tutorial

What is a bus?

Buss is a concept that is important to be able to understand the behavior of the motherboard. A bus consists of multiple lines or signal paths that connect devices in a computer. These signal paths forms address bus, data bus and the control bus. Each device has a unique address. The bus link will explain the link data to be transferred to. Data bus transfers data and control bus controls the flow of the transfer of data.

To give a very simple example, let us imagine a bus with 8 bit of data, 3 bit for the link and a bit of control. The communication takes place over a predetermined communication protocol. This means that the devices on the bus is pre-programmed to recognize certain data. For example, one can say that if the first 5 data lines are set to 00110 so this means "I would like to know your status", the last 3 says that the data set who is from (the sender's address).

Let us now say that more devices are connected to this bus, including device A link with the 001 and unit B with the address 111 Now, the A to know the status of B. This means that A must put the address bar to 111, the first 5 data lines to 00110 (which means "I would like to know your status"), the last three data lines to 001 (to set the sender address) and control signals to a value which means that data is valid on the data bus. Then you can wait in anticipation for A.

Check the signal that was set by A tells B that it is valid data on the bus. A look at bus link to see if the data is addressed to him. When the address matches, take the B data from the bus and the interpreters. The data is 00110001. This B knows that means "I would like to know your status, greeting link 001". Then B add their status on the data lines, the address of the device and asked for the address bar and appropriate control signals to indicate that valid data is available must be put on the control bus.

Different types of buses

On the motherboard, there are many different buses. Some are internal and some are external. The external buses are the ones we can connect the devices on the outside. For example, the PCI and PCI Express bus, there are physical traces on the motherboard so that we can connect for example, a network adapter. The internal buses are those that are not available for new connections, such as the processor bus that connects the processor and the north side.

The most common buses that are on the motherboard are:

-Front-Side Bus (FSB) - Between the processor and the north side
Memory-Bus - Between the memory controller and memory
-Accelerated Graphics Port (AGP) - Bus for connecting video
Low-Pin Count (lpc) - Bus for BIOS and connection (via the Super I / O) of the keyboard, serial port, etc..
-Peripheral Component Interface (PCI) - For the connection of such. sound card
PCI-Express - Newer and faster version of PCI bus.

Northbridge

Through the north side connects devices with high demands on the speed of data transfer. Graphics and memory are typical examples of such devices. Some of the north page functionality on newer motherboards has been moved into the processor.

Front-side bus

North Since the processor is connected directly through a "Front-side Bus (FSB). This is typically the fastest bus in a computer. Through this bus, all communication goes with the processor. Therefore, the performance of this bus is very important for the overall performance of the system. Performance of the FSB has been given by three parameters: bus width (for data), the clock frequency and the number of transfers per clock cycle. Eg. can a 32-bit bus that can perform two transfers per cycle with a clock of 400 MHz to provide a theoretical top speed of just over 3000 MB / s.

Bus Picture

Advanced video cards are in need for rapid transmission of data in order to provide optimal. Until recently, the "Accelerated Graphics Port (AGP) was much higher for graphics, but it is now phased out of the PCI Express x16.

Memory controller

Memory controller's job is to write, read and regularly update the dynamic memory (DRAM). DRAM must be updated often to not lose their data. There are only a few dozen milliseconds needed before DRAM loses its data if it is not being updated.

Interface to the south

For the processor to be able to communicate with the south side, there is a bus interface in the north that provides for communication to the south. This interface can vary from chipset to chipset.

South

In the south we find the devices unless the demands for rapid data transfer, including control of USB, hard drives, direct memory access (DMA) and disruption.

DMA controller

The controller for direct memory access or "Direct Memory Access (DMA) Controller" is a component that allows the devices to directly access the memory in place of it to go through the processor. This allows the processor to concentrate on other tasks while accessing memory devices.

Interrupt controller

This controller handles hardware interruption coming from the various devices in the computer. For example, if your network has received the data must be in some way to say in from so that the computer can use this data. If you enter http://hackforums.net in your browser, your browser will send a request to this website to see the contents. The site responds by sending you the content. This data is first presented to the network. The network adapter must then send an interrupt to interrupt controller which says in from the processor that a disruption has occurred. Interrupt controller has signal paths that says in from directly to the processor. The processor will then take a break from the work and run a small program that is associated with the current interruption. This program will consist of instructions that allow the processor to retrieve data from the network and add the memory. The browser can now get hold of this data and view it as a web page in your browser. (Note: This is just an example to show how it works; it is not necessarily that all network cards look like this.

USB controler

"Universal Serial Bus" is a connection standard that is very prevalent today. Here you can connect everything from printers and scanners to the fans and coffee warmer. It was previously plugged into the parallel port or serial port is today often converted to USB devices. Many hobby developers resented over the serial port is often no longer available for example. new laptops. This is actually a port that is relatively easy to program against in relation to the USB. Fortunately, there are a USB standard that supports virtual serial ports, and there are many USB-to-serial products out there so you still can program against the serial port as previously.

SATA controller

SATA or Serial Advanced Technology Attachment "controller is used to connect hard drives or optical drives (eg. CD-ROM).

Audio Codec

Some motherboards have the audio codec integrated in the south. This is a small hardware section which converts from analog to digital audio signals, and vice versa. This is basically an integrated sound card.

Various other components on the motherboard

On the motherboard, there are also more components than just north and south. Many of these are connections to other devices, such as contacts for PCI or memory, but on some motherboards are also the pieces of the network, graphics and sound. A very important component that is small on the motherboard is BIOS.

BIOS

Basic Input / Output System (BIOS) is the part of the motherboard that gets the computer to start up. Here you can when your computer starts up select different settings, for example the order in which the BIOS to look for storage devices with boot properties or the frequency clock is running on.
When the power is turned on the processor is set to review its first instruction from a particular memory location in the BIOS. The instruction that is stored in this location is usually a single jump instruction that tells the processor where the boot-load is located in the BIOS memory. The processor jumps to the boot-load's position and continues the execution thereof. A boot-loader is only a single application that usually loads a second-stage boot loader such as GRUB, LILO or NTLDR. This will then load the operating system.

CMOS battery

This is a small battery that keeps the real time clock running. It is this that makes the computer able to know the time even after power has been denied on the computer. On older computers where the BIOS settings were stored in RAM, this battery was also responsible for the RAM chip when it had power. If you have forgotten your BIOS password, for example, be able to take out the CMOS battery and short-circuit terminals to reset all the BIOS settings. The settings were stored on a CMOS-based RAM-chip, hence the name the CMOS battery.

Slots for PCI / PCI Express

Here it’s placed accessories such as sound cards or network adapters. PCI Express x16 slot is connected to the north side for extra speed, the other tracks are connected to the south.

Memory Slot

Memory Slot is that the word implies a place where memory modules are placed. There are limits on how much memory and what kind of memory you can insert. This is usually given the type of chip that is placed on the motherboard.

Super I / O

A piece for the connection from the mouse, keyboard, serial port, parallel port and floppy drive. This piece connects lpc bus via an interface in the south.

ATA connections

ATA (Advanced Technology Attachment) connection used to connect storage devices such as on hard drives and CD-rom. This connection is a technology that has evolved from Western Digital original "Integrated Drive Electronics" interface from 1986. In 2003, Serial ATA (SATA) was introduced and as a result was the former ATA version name Parallel ATA (PATA).

Clock Generator

Clock Generator determines the frequency processor to run with. The frequency can be changed using the settings in the BIOS. (Note: I recommend that only those who know what they are doing is changing in this setting as it may have consequences for your computer.

Summary

We have in this guide looked at how the architecture of a motherboard looks like and what components it consists of. In the section on the buses, we went through how a bus works and gave an example of how communication on a planned 8-bit bus could be.
We have gone a little further into what is hidden inside the chip and we have learned that all communication with the processor is done through the chipset. In the section on the north side, we learned that there are in units with high demands for rapid data online and we went through the devices that were in the south.
Finally, we saw some of the components can be observed on a motherboard. Among other things, we went into the BIOS his mission to start up the machine and we learned that there are in the first instruction that the processor is working with.

Hope you learned something by reading this Guide for beginners.