Computer Systems Architecture

Computer Systems
Architecture
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Contents
Introduction......................................................................................................................................4
LO1 Understand how data can be represented within computer systems.......................................5
P1. Explain using examples how numeric and alphanumeric data can be coded within a
computer system..........................................................................................................................5
P2. Explain using examples how different types of data can be converted and stored in
computer system..........................................................................................................................7
P3. Convert numeric data between different number systems including floating point..............9
LO2 Understand the functions of computer system components..................................................18
P5. Illustrate the key computer system components and how they interact..............................18
P6. Explain the different types of memory that can be attached to a processor........................21
P7. Explain how polling and interrupts are used to allow communication between processor
and peripherals...........................................................................................................................24
LO3 Understand the principles of processor operations................................................................25
P8. Compare Reduced Instruction Set Computer (RISC) chips and Complex Instruction Set
Computer (CISC) chips.............................................................................................................26
P9. Illustrate the use of the different processor registers in the fetch-execute cycle.................29
Conclusion.....................................................................................................................................32
References......................................................................................................................................33
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List of Figures
Figure 1- Image representation........................................................................................................7
Figure 2- OR Gate.........................................................................................................................12
Figure 3- AND Gate......................................................................................................................12
Figure 4- NOT Gate.......................................................................................................................13
Figure 5- NAND Gate...................................................................................................................13
Figure 6- NOR Gate.......................................................................................................................14
Figure 7- XOR Gate.......................................................................................................................15
Figure 8- Combined Circuit...........................................................................................................15
Figure 9- Von-Neumann architecture............................................................................................18
Figure 10- Scanner.........................................................................................................................18
Figure 11- CPU..............................................................................................................................19
Figure 12- Program counter...........................................................................................................20
Figure 13- Printer...........................................................................................................................20
Figure 14- SRAM..........................................................................................................................21
Figure 15- DRAM..........................................................................................................................21
Figure 16- ROM............................................................................................................................21
Figure 17- Flash memory...............................................................................................................22
Figure 18- Cache Memory.............................................................................................................22
Figure 19- GPR..............................................................................................................................23
Figure 20- Polling..........................................................................................................................24
Figure 21- Occurrence of interrupts..............................................................................................24
Figure 22- Pipelining.....................................................................................................................25
Figure 23- Parallel processing.......................................................................................................25
Figure 24- Multiprocessing............................................................................................................25
Figure 25- CISC Architecture........................................................................................................26
Figure 26- RISC Architecture........................................................................................................27
Figure 27- Fetching........................................................................................................................30
Figure 28- Decoding and Storing Data..........................................................................................30
Figure 29- Execute.........................................................................................................................31
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List of Tables
Table 1- ASCII Table......................................................................................................................6
Table 2- OR gate truth table..........................................................................................................12
Table 3- AND gate Truth Table.....................................................................................................13
Table 4- NOT Gate Truth Table....................................................................................................13
Table 5- NAND Gate Truth Table.................................................................................................14
Table 6- NOR Gate Truth Table....................................................................................................14
Table 7- XOR Gate Truth Table....................................................................................................15
Table 8- Truth table.......................................................................................................................16
Table 9- CISC v/s RISC................................................................................................................28
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Introduction
Computer Architecture is a combined network of hardware and software to form a computer
system which defines a relation and connection between them. It characterizes how hardware and
software tools communicate with each other in a computer system. At present time most of the
system use this architecture principle. The most famous and reliable computer architecture is
Von Neumann Architecture and almost every system is designed on this architecture at present
time.
The purpose of this assignment is to establish the new subject of Computer Mathematics for
government-funded college. This subject is introduced to define that how computer machines are
performing various types of calculation and feeding the proper output as per the requirements. So
in this assignment, I had introduced topics like Von Neumann Architecture, conversions of
different base numbers, text, images, and videos into the low-level language which can be
understood by computer machine. Also, the fetch-execution cycle which defines the order of
execution of instructions in a system.
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LO1 Understand how data can be represented within computer systems
P1. Explain using examples how numeric and alphanumeric data can be coded
within a computer system
In order to conceptualize how different data is coded within a computer system, there is the need
to first understand what is numeric type data and alphanumeric data. Numeric data is the form of
information that can be represented in number form i.e. the information that can be countable
and can be represented in mathematical form. Some of the common examples are integers,
floating points and octal.
 Integers: Integers are those which are whole in nature and uses base from 0 to 9. Hence
numbers formed ranges from 0 to trillions like 1, 56406, 89410512564231 etc.
 Floating points: A number with a decimal is known as floating point number. Position of
decimal is not precise like 1.2, 1145.0641, 4785421.33. All these are an example of
floating point numbers (Corio, 2014).
 Octal: Octal numbers are the number which uses base from 0 to 7. All the numbers
formed in octal system have base 8 (ElectronicsHub, 2015).
Alphanumeric data is the combination of alphabets and numbers. It comprises some special
symbols like *, @, #, & and characters representing 0-9 and a-z (both upper and lower case) and
Hexadecimal system is the best example of alphanumeric data. It uses base 16 i.e. numbers 0-9
and A to F uppercase letters to show its decimal numbers. For example, 16,295 can be
represented as 3FA7 in hexadecimal system (Jackson, 2017).
Computer understands binary language or binary system. It has 2 components that are 0s and 1s.
It is similar to our electric home switches just ON (represented by 1s) and OFF (by 0s). All the
instructions within systems are performed through bits (0 & 1 are bit) and a series of 8 bits is
called 1 Byte. All the data in a computer is stored in bits or combination of bits (Bytes), a
combination of bytes (Mega-Bytes MB) and so on. The process of interpreting raw 0s and 1s
and converting it into real character can be described as Character Encoding. There are many
different types of character encoding standards exist like ASCII (American Standard Code for
Information Interchange), ANSI (American National Standards Institute), Unicode and ASCII
being the first character encoding standard is widely used for representing English characters
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and integers as numbers, each letter assigned a value from 0-127 uniquely. ASCII defines 7-bit
code with total 128 (0-127) ASCII values. To extend these ANSI extend it to 8 bit and introduce
different code pages for symbols 128 to 255 whereas Unicode is a platform-independent internal
text coding system used in all computer system, whether it is Windows, Linux, Unix because it
can handle almost all languages. Now at present, we have worldwide accepted encoding
standard to process text and data into machine language. But how it is performed by the system.
Let's take the example of conversion of text into ASCII code. But before that, there is the need
of ASCII code table which is shown below:
Table 1- ASCII Table
Let's take an example to understand it better.
Example: RAT
Now to get ASCII code for “RAT”, look at the value of letters in above table. R=82, A=65,
T=84. Hence ASCII code for RAT will be 82 65 84 and its corresponding binary code is
00111000 00110010 00100000 00110110 00110101 00100000 00111000 00110100
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P2. Explain using examples how different types of data can be converted and stored
in computer system
Different data can be stored in computer system like images, audios, videos, text files and all the
specific type have a specific format. Images stored in JPEG (Joint Photographic Experts Group),
JPG (Joint Photographic Group), PNG (Portable Network Graphics), GIF (Graphics Interchange
Format). Similarly, audios in mp3 format and videos in mp4 and text files in various formats like
.txt, .doc depending on requirement. Different type of file format tells user about the file type
without opening it as well as to computer and then instruction is executed to process them. But
how all these are stored in computer and displayed to user (Fisher, 2018).
An image is a collection of small dots known as pixel. Thus a group of small illuminating dots
combined together form a picture or image and is stored in system in same way. But computer
stores all the things in binary system. Hence images are also stored in binary form where 0
represent white and 1 is black (Cooper, 2015).
Figure 1- Image representation
Source- (Computerscience, 2017)
Further combination of 0s and 1s produce different colours. Each and every colour of image is
stored as a binary number. A computer screen which shows images consist of thousands of pixels
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