What Is A Bus Concept

Published Date: 02 Nov 2017

1. Introduction 2

2. Define Question 1 3

3. Answers for Question 1 4-9

4. Define Questions 2 10

5. Answers for Question 2 11-13

6. Conclusion 14

7. Appendix 15

8. Bibliography 16

Introduction

With the invention of the microprocessor, all functions of a computer's central processing unit could be handled by a single integrated circuit. These processors were small and could be used in a variety of small devices, most notably the personal computer. Over the years, engineers have been able to make the microprocessor faster and more reliable, while maintaining the miniaturized size. During the early part of the 21st century, major advancements have continued this tradition, doubling its power with each generation.

(The history of the processor,1999)

A bus is an electrical system that is shared by several hardware devices, such as cables or printed circuits, which are connected so that the people on individual computers are able to easily and quickly communicate with one another.

The bus in the computer's architecture, which allows the various devices to communicate. For example, if multiple computers are attached to one printer, a person can hit print and use the bus to speak with the printer. The bus system helps to make the transportation of data easier and much more direct.

(What is a Bus concept in bus structure, 2002)

Define Question 1

Traditionally we often see with the single core processor which is very slows down the maximum speed that the bus, once the RAM and storage device is allow this is why is slower than the CPU. But current days having a microprocessor, which is multitasking with came up a small unit, sized an ideals for all the users for demanding a high speed yet processor.

Answer for Question 1

The first single chip CPU was the Intel 4004 invented in Nov 1971, a 4-bit processor meant for a calculator. It processed data in 4 bits, but its instructions were 8 bits long. Program and data were separate.

In 1972, Texas Instruments followed the Intel 4004/4040 closely with the 4-bit TMS 1000, which was the first microprocessor to include enough RAM, and space for a program ROM, to allow it to operate without multiple external support chips. It also featured an innovative feature to add custom instructions to the CPU.

The 8080 was the successor to the 8008 in April 1972. While the 8008 had 14 bit PC and addressing, the 8080 had a 16 bit address bus and an 8 bit data bus. Internally it had seven 8 bit registers, a 16 bit stack pointer to memory which replaced the 8 level internal stack of the 8008, and a 16 bit program counter. It also had several I/O ports - 256 of them, so I/O devices could be hooked up without taking away or interfering with the addressing space, and a signal pin that allowed the stack to occupy a separate bank of memory. Intel updated the design with the 8085 in1976, which added two instructions to enable/disable three added interrupt pins and the serial I/O pins, and simplified hardware by only using +5V power, and adding clock generator and bus controller circuits on-chip. The 8080 was the successor to the 8008 in April 1972. While the 8008 had 14 bit PC and addressing, the 8080 had a 16 bit address bus and an 8 bit data bus. Internally it had seven 8 bit registers, a 16 bit stack pointer to memory which replaced the 8 level internal stack of the 8008, and a 16 bit program counter. It also had several I/O ports - 256 of them, so I/O devices could be hooked up without taking away or interfering with the addressing space, and a signal pin that allowed the stack to occupy a separate bank of memory. Intel updated the design with the 8085 in1976, which added two instructions to enable/disable three added interrupt pins and the serial I/O pins, and simplified hardware by only using +5V power, and adding clock generator and bus controller circuits on-chip.

The Z-80 was intended to be an improved 8080 in 1976, and it was - vastly improved. It also used 8 bit data and 16 bit addressing, and could execute all of the 8080 (but not 8085) op codes, but included 80 more, instructions. The register set was doubled, with two banks of data registers that could be switched between. This allowed fast operating system or interrupt context switches. The Z-80 also added two index registers and 2 types of reloadable-vectored interrupts. The thing that really made the Z-80 popular in designs was the memory interface - the CPU generated its own RAM refresh signals, which meant easier design and lower system cost, the deciding factor in its selection for the TRS-80 Model 1. That and its 8080 compatibility, and CP/M, the first standard microprocessor operating system, made it the first choice of many systems.

Shortly after Intel's 8080, Motorola introduced the 6800 in 1975. Some of the designers left to start MOS Technologies, which introduced the 650x series, which included the 6501 pin compatible with the 6800, taken off the market almost immediately for legal reasons and the 6502. Like the 6800 series, variants were produced which added features like I/O ports or reduced costs with smaller address buses 6507 13-bit 8K address bus in the Atari 2600. Apple designer Steve Wozniak described it as the first chip you could get for less than a hundred dollars actually a

Like the 6502, the 6809 was based on the Motorola 6800, though the 6809 expanded the design significantly. The 6809 had two 8 bit accumulators and could combine them into a single 16 bit register. It also featured two index registers and two stack pointers, which allowed for some very advanced addressing modes. The 6809 was source compatible with the 6800, even though the 6800 had 78 instructions and the 6809 only had around 59. Some instructions were replaced by more general ones which the assembler would translate, and some were even replaced by addressing modes. While the 6800 and 6502 both had a fast 8 bit mode to address the first 256 bytes of RAM, the 6809 had an 8 bit Direct Page register to locate this fast address page anywhere in the 64K address space.

(History of CPU, 2010)

A dual core processor for a computer is a central processing unit as known as CPU that has two separate cores on the same die, each with its own cache. It essentially is two microprocessors in one. This type of CPU is widely available from many manufacturers. Other types of multi-core processors also have been developed, including quad-core processors with four cores each, hexa-core processors with six, octal-core processors with eight and many-core processors with an even larger number of cores.

In a single-core or traditional processor, the CPU is fed strings of instructions that it must order, execute, then selectively store in its cache for quick retrieval. When data outside the cache is required, it is retrieved through the system bus from random access memory RAM or from storage devices. Accessing these slows down performance to the maximum speed that the bus, RAM or storage device will allow, which is far slower than the speed of the CPU.

This situation is compounded when the computer user is multi-tasking. In this case, the processor must switch back and forth between two or more sets of data streams and program. CPU resources are depleted, and performance suffers.

In a dual core processor, each core handles incoming data strings simultaneously to improve efficiency. Just as two heads are better than one, so are two hands. When one core is executing, the other can be accessing the system bus or executing its own code.

(What is dual core processor, 2003)

For laptops

Initially, most laptop users are concerned with simply mobility and the yse of regular computer tools, such as listening to music or watching a movie, using basic software like Microsoft word or for the internet. For these users the main concern of the price of its laptop and that is why they prefer getting a AMD it is cheaper and affordable.

For Desktop

A desktop enthusiast can get a lot better to configuration not their computer because a desktop is cheaper than a laptop. Most desktop users today require least amount of gaming compatibility. This is where it gets a little tough to choose. Then are some basic differences between AMD and Intel this is where the main difference between AMD and Intel

Clocking Speed

If clocking speed was still a sole criteria for superiority as it used to be in the old days, Intel would win hands down. But that's not the case anymore. Intel processors give you a higher clocking, which means they have a higher frequency of work done per second. That's just how it is built- Intel divides the total work down to the smallest possible divisions for simplicity and goes through it a high frequency. AMD, on the other hand, goes through data at a slower rate, but processes a lot more data per cycle. In the end, the amount of data processed by the AMD can be quite significant.

This is the reason why the processing frequency cannot be taken into consideration while selecting between the two brands. I only added this point to help you understand this, so you won't be confused by a dealer when he says Intel is better because it has more speed, just to make a sale.

Overall Performance

This is a rather tricky area. If you compare versions with the same ratings, you'll find that Intel beats AMD in most areas when it comes to performance. But, ever since AMD got hold of ATI, the AMD processor has a much higher compatibility with any ATI graphics cards. AMD started reworking their strategy at that time and integrated both systems quite well. So, if you're a gamer and want to buy an ATI graphics card, you'd be better off with an AMD processor.

There are, however, a few Intel processors that have integrated graphics support have turned out quite good for gaming purposes. As the market currently stands, the high-end AMD processors can give you only so much processing capability as the first generation Intel processors. Which keeps the performance market quite an open ground for the high-end Intel processors. If you're not really into gaming and want good performance for something like vitalizing your machine or video encoding, you can go with Intel.

Another category for gauging performance is multitasking abilities. For software or an application, multitasking refers to its ability to divide its work into smaller pieces for faster computing. If you are using such software that allow multitasking, choose Intel, because of Hyper-Threading, a technique in Intel that allows faster, efficient multitasking.

Pricing

This is where the debate takes a huge detour. For all the numbers that Intel shows you to be better than AMD, there is one figure that most don't want to appreciate to be larger- the price. Current Intel processors may be better than AMD simply because AMD are cheaper than processors from the statistic 20% to 60%. Age range gamers from their 30 years old and above they will agree that current generations Intel is a little out of their reach which did not full fill their requirements. This is why the gamers choose AMD instead for game and stick with it. Current Intel processors and AMD are very much the same price for a graphic card, which sometimes Intel may be higher.

(Buzzle, 2013)

Definition of Question 2

The purpose of having bus is a collection of wires through which contains a data will transmitted one part to another to implementing an internal communication. Bus as in a highway on which data travels just within the computer. It connects to all the internal part including CPU and main memory it also divided into buses which is address bus and data bus

Answer question 2

Computers comprises of many internal components and in order for these components to communicate with each other, a bus is used for that purpose.

A bus is a common pathway through which information flows from one component to another. This pathway is used for communication purpose and can be established between two or more computer components. We are going to review different computer bus architectures that are used in computers.

The functions of buses

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 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.

Figure 1 : Bus diagram

(Source: Asynchronous Events : Polling Loops and Interrupts, 2002)

Bus Terminologies

Computers can be viewed to be having just two types of buses:

1. System bus The bus that connects the CPU to main memory on the motherboard. The system bus is also called the front-side bus, memory bus, local bus, or host bus.

2. A number of I/O Buses, Acronym for input/output, connecting various peripheral devices to the CPU -these are connected to the system bus via a bridge implemented in the processors chipset. Other names for the I/O bus include expansion bus, external bus or host bus.

These are some of the common expansion bus types that have ever been used in computers:

ISA - Industry Standard Architecture

EISA - Extended Industry Standard Architecture

MCA - Micro Channel Architecture

VESA - Video Electronics Standards Association

PCI - Peripheral Component Interconnect

PCMCIA - Personal Computer Memory Card Industry Association Also called PC bus

AGP - Accelerated Graphics Port

SCSI - Small Computer Systems Interface.

PCI Peripheral Component Interconnect is an interconnection system between semi processor attached devices in which expansion slots is spaced closely for high speed operation. Using PCI, a computer can support both new PCI cards while continuing to support Industry Standard Architecture (ISA) expansion cards, an older standard. Designed by Intel, the original PCI was similar to the VESA Local Bus. However, PCI 2.0 is no longer a local bus and is designed to be independent of microprocessor design. PCI is designed to be synchronized with the clock speed of the microprocessor.

PCI is now installed on most new desktop computers, not only those based on Intel's Pentium processor but also those based on the PowerPC. PCI transmits 32 bits at a time in a 124-pin connection the extra pins are for power supply and grounding and 64 bits in a 188-pin connection in an expanded implementation. PCI uses all active paths to transmit both address and data signals, sending the address on one clock cycle and data on the next.

(Techtarget,2013)

Conclusion

In conclusion, CPU these days are definitely more advance and enhance of its feature into another level regardless in graphic, interface and speed were very impressive the users with only a demanding mindset simply because in the current market there are many choices which allows the users to choose unlike the ancient processor which just single core and dual core or even older version where it does not have all these features to be chose but with gradually research and development with now the invention have been invented a very good processor to the users to uses it that is why users these days is not satisfied with what they want because its various availability in the market. I would hope the processor will be more advance in the future.

Buses are providing transportation of how its data flow, the bus and irs working speed are really important for the overall computer system if a transportation for its internal parts has breakdown it will indirectly affecting and clogging the system. It is also the responsible for data transferring from one unit to another unit by sending data.

Appendix