Exploring the Future Potential of AI-Enabled Smartphone Processors
Lecture 1
1. GITAM UNIVERSITY
(Declared as Deemed to be University U/S 3 of UGC Act, 1956)
Lecture Notes
of
Programming with C
[ERUCS 105]
INTRODUCTION
Lecture-1
Hyderabad Campus, Rudraram
HYDERABAD-502329
JULY-NOV 2013
3. 1 COMPUTERS
1
1 Computers
The Computer is a programmable finite state machine which can perform precise
arithmetic and logic operations.
4. A programmable finite state machine is one that can take one of a fixed range
of values. The computer is said to be programmable because it can instructed to
perform tasks within it’s capacity.
When we talk about a computer, we actually mean two things
First is the computer hardware that does all the physical work computers are known
for.
Second is the computer software that commands the hardware what to do and how
to do it.
A list of instructions can be submitted to the computer in the form of a program.
Figure 1: Parts of Computer System
a task is performed by executing the corresponding program. A collection of related
programs is referred to as the software. The physical circuitry and components are
known as the hardware. Hardware can be categorized into five blocks.
They are:
• Input Unit
• Arithmetic logic Unit(ALU)
• Control Unit(CU)
• Memory Unit
• Output Unit
1.1 Input Unit
The input unit is the device used to enter data and instructions into the computer. The
data read from the input device is stored in the computer’s memory.
5. Some common input devices are: Keyboard, mouse, joystick, light pen, etc.
1
PROGRAMMING with C[ERUCS 105]
3
6. 1.2 Arithmetic Logic Unit(ALU) 1 COMPUTERS
2
1.2 Arithmetic Logic Unit(ALU)
The ALU performs arithmetic and logic operations. The arithmetic operations include
addition, subtraction, multiplication and division.
Figure 2: Hardware blocks of a computer
1.3 Control Unit(CU)
The control unit coordinates the activities of the various components of a computer.
The arithmetic logic unit and the control unit together comprise the Central processing
Unit(CPU). The CPUs are called Microprocessor. The speed of a computer depends
on the clock frequency of the microprocessor.
7. Some popular microprocessors are: Intel, Pentium, Pentium Pro, IBM, AMD, etc.
1.4 Memory Unit
The information(instructions and data) required is stored is stored in memory. The
computer memory is constructed out of semi-conducting material and stores information
in binary form. Binary information is composed of two symbols o and 1, called binary
digits(bits). All information within the computer is represented by two digits. The
memory is organized into equal sized units(usually a collection of 8 bits, called byte).
These units are arranged in a sequence and are identified by numbers called addresses.
8. The memory of a computer can be divided into distinct parts. They are:
• Registers
• Internal Cacahe
• External Cache
• Main memory
• Secondary memory
2
PROGRAMMING with C[ERUCS 105]
4
9. 1.5 Output Unit 1 COMPUTERS
3
1.5 Output Unit
Just s input devices are used to supply the computer with data, there should be some
means for the computer to communicate with the user. The information generated by
the computer is displayed using an output device.
10. Some examples of output devices are: Cathod Ray Tube(CRT), Printer, Card
punch, plotters, etc.
1.6 Classification of computer software
Computer software can be brodely classified into two groups: System software and
application software.
• System software provides a general programming environment in which programmers
can create specific applications to suite their needs. This environment provides new
functions that are not available at the hardware level and performs tasks related to
executing the application program.
• Application software is designed to solve a particular problem for users. It is generally
what we think of when we say the word computer programs.
11. Examples of application software include spreadsheets, database systems, desktop
publishing systems, program development software, etc.
Figure 3: Relationship between hardware and software
3
PROGRAMMING with C[ERUCS 105]
5
12. 2 CLASSIFICATION OF COMPUTERS
4
2 Classification of Computers
The Abacus was invented around 2500 BC. It is a device made of beads strung on
rods and used to perform simple computations.
Napier invented a device for computing logarithms of natural numbers. It was called
Napier’s Bones and enabled multiplication to be done easily.
Blaise Pascal invented the addressing machine in 1642 AD.
charless Babbage designed the difference engine in 1822 AD and analytical engine
in 1833 AD.
Computers can be classified into five generations, based on the technology and performance
and is shown in Table 1.
Table 1: Generations of Computer
Generation Year Hardware Software Performance
Zero Pre 1946 Counter wheels
with mechanical
components
− − −− Numerical op-
erations at slow
speed
First 1946-1956 Vacuum Tubes Stored Pro-
grams, Machine
Code, Symbolic
code
2 KB Memory, 10
Kilo instructions
per second
Second 1956-1963 Transistors High Level Lan-
guage(HLL),
FORTRAN,
ALGOL, etc
32 KB Memory,
200 Kilo instruc-
tions per second
Third 1964-1981 ICs, Semi-
Conductor
memory
PASCAL, C, etc 2 MB Memory,
5 Million In-
structions Per
Second(MIPS)
Fourth 1982-1989 VLSI OOPs Lan-
guages: C++,
etc
32 KB Memory,
30 Million In-
structions Per
Second(MIPS)
Fifth 1990-
NOW
Parallel Process-
ing
JAVA, .NET, etc 1 Giga to 1 Tera in-
structions per sec-
ond
4
PROGRAMMING with C[ERUCS 105]
6
13. 3 GENERATION OF PROGRAMMING LANGUAGES
5
3 Generation of Programming Languages
A Programming language is a language specially designed to express computations
that can be performed by the computer. programming languages are used to create
programs that control the behaviour of a system, to express algorithms, or as a mode of
human-computer communication.
We now know that programming languages are the primary tools for creating software.
As of now hundreds of programming languages exits in the market, some more used than
others, and each claiming to be the best. However, back in 1940s when computers were
being developed there was just one language-the machine language.
The concept of generations of programming languages (also known as levels), is closely
connected to the advances, in technology that brought about computer generations. The
four generations of programming languages include:
• Machine language
• Assembly language
• High level Languages(HLL) (also known as third generation languages or 3GL)
• very High level Languages(HLL) (also known as fourth Generation Languages or 4GL)
3.1 First Generation: Machine Language
Machine language was used to program the first stored program on computer system.
This is the lowest level of programming language. The machine language is the only lan-
guage that the computer understands. All the commands and data values are expressed
using 1 and 0s, corresponding to the ’on’ and ’off’ electrical states in a computer.
The main advantage of machine language is that the code can run very fast and effi-
ciently, since it is directly executed by CPU. However, on the down side, the machine
language is difficult to learn and is far more difficult to edit if errors occur. Moreover, if
you want to add some instructions into memory at some location, then all the instruc-
tions after the insertion point would have to be moved down to make room in memory
to accommodate the new instructions.
3.2 Second Generation: Assembly Language
The second generation of programming language includes the assembly language. As-
sembly languages are symbolic programming languages that use symbolic notation to
represent machine-language instructions. These languages are closely connected to ma-
chine language and the internal architecture of the computer system on which they are
used. Since they are close to the machine, assembly language is also called low-level
language. Assembly language developed in the mid 1950s was a great leap forward. It
used symbolic codes also known as mnemonic codes that are easy-to-remember abbre-
viations, rather than numbers, Examples of these code include ADD for add, CMP for
compare, MUL for multiply, etc.
5
PROGRAMMING with C[ERUCS 105]
7
14. 3.3 3GL: HLL 3 GENERATION OF PROGRAMMING LANGUAGES
6
3.3 3GL: HLL
A third generation programming language(3GL) is a refinement of the second generation
programming language. The 2GL languages brought logical structure to the software.
The third generation language was introduced to make the languages more programmer
friendly.
Generally, a statement written in high-level programming language will expand into sev-
eral machine language instructions. This is in contrast to assembly languages, where one
statement would generate one machine language instruction. 3GLs made programming
easier, efficient, and less prone to error.
3GL make it easier to write and debug a program and gives the programmer more time
to think about its overall logic. The programs written in such languages are portable
between machines.
15. A program written in standard C can be compiled and executed on any computer
that has a standard C compiler.
3.4 4GL: Very High Level Languages
with the generation, programming languages started becoming easier to use and more like
natural languages. However, 4GLs is a little different from its prior generation because
they are basically non-procedural. When writing code using a procedural language,
programmer has to tell the computer how a task is done – add this, compare that, do
this if the condition is true, and so on, in a very specific step-by-step manner.
16. A typical example of a 4GL is the query language that allows a user to request
information from a database with precisely worded English-like sentences.
6
PROGRAMMING with C[ERUCS 105]
8
17. 4 SAMPLE PROGRAMS
7
4 Sample Programs
4.1 The While Loop
• In ’C’ programming that user want to do something a fixed number of times.
• The while loop is ideally suited for such cases.
The while loop is suited for following cases.
CASE-1:
• If you want to calculate gross salaries of ten different persons.
CASE-2:
• If you you want to convert temperatures from centigrade to fahrenheit for 15 different
cities.
Example:
1 /∗ Calculation of simple i n t e r e s t for 3 s e t s of p , n and r ∗/
2 #includestdio . h
3 main( )
4 {
5 int p , n , count ;
6 float r , s i ;
7 count = 1;
8 while ( count = 3 )
9 {
10 p r i n t f ( ” Enter values of p , n and r ” ) ;
11 scanf ( ”%d %d %f ” , p , n , r ) ;
12 s i=p∗n ∗ r / 100 ;
13 p r i n t f ( ”Simple i n t e r e s t = Rs . %f ” , s i ) ;
14 count=count+1;
15 }
16 }
example1.c
Sample Output:
Enter values of p, n and r 1000 5 13.5
Simple interest = Rs. 675.000000
Enter values of p, n and r 2000 5 13.5
Simple interest = Rs. 1350.000000
Enter values of p, n and r 3500 5 13.5
Simple interest = Rs. 2362.500000
7
PROGRAMMING with C[ERUCS 105]
9
18. 4.1 The While Loop 4 SAMPLE PROGRAMS
8
Analysis:
• The program executes all statements after the while 3 times.
• The logic for calculating the simple interest is written within a pair of braces
immediately after the while keyword.
• These statements form what is called the body of the while loop.
• The parentheses after the while contain a condition. So long as this condition remains
true all statements within the body of the while loop keep getting executed repeatedly.
• To begin with the variable count is initialized to 1 and every time the simple interest
logic is executed the value of count is incremented by one.
• The variable count is many a times called either a loop counter or an index variable.
Syntax
initialise loop counter ;
while ( test loop counter using a condition )
{
do this(Statement-1) ;
and this(statement-2) ;
increment loop counter ;
}
Figure 4: While Loop syntax
8
PROGRAMMING with C[ERUCS 105]
10
19. 4.1 The While Loop 4 SAMPLE PROGRAMS
9
Figure 5: While Loop Flowchart
Note-I
The statements within the while loop would keep on getting executed till the condi-
tion being tested remains true. When the condition becomes false, the control passes
to the first statement that follows the body of the while loop.
Note-II
The condition being tested may use relational or logical operators as shown in the
following examples:
while ( i = 10 )
while ( i = 10 j = 15 )
Note-III
The statements within the loop may be asingle line (or) a block of statements.
Examples:
while ( i = 10 )
i=i+1;
is same as
while ( i = 10 )
{ i=i+1;
}
9
PROGRAMMING with C[ERUCS 105]
11
20. 4.1 The While Loop 4 SAMPLE PROGRAMS
10
Note-IV
As a rule while must test a condition that will eventually become false. Otherwise
the loop would be executed forever, indefinitly.
main()
{
int i=1;
while ( i = 10 )
printf(”%d”,i);
}
The correct form would be as under
main()
{
int i=1;
while ( i = 10 )
{ printf(”%d”,i);
i=i+1;
}
}
Note-IV
Instead of incrementing a loop counter, We can even decrement it and still manage
to get the body of the loop executed repeatedly.
This is shown below:
main( )
{
int i = 5 ;
while (i = 1 )
{
printf (”Make the computer literate” ) ;
i = i - 1 ;
}
}
Note-V
It is not necessary that a loop counter must only be an int. It can even be a float.
main( )
{
float a = 10.0 ;
while (a = 10.5 )
{
printf ( ” addition”);
a = a + 0.1 ;
}
}
10
PROGRAMMING with C[ERUCS 105]
12
31. What is a micro processor?
11
PROGRAMMING with C[ERUCS 105]
13
32. 6 SNIPPET PROGRAMS
12
6 Snippet Programs
What would be the output of the following programs
(a) main( )
{
void slogan( ) ;
int c = 5 ;
c = slogan( ) ;
printf ( ”% d”, c ) ;
}
void slogan( )
{
printf ( ”Only He men use C!” ) ;
}
(b) main( )
{
void slogan( ) ;
int c = 5 ;
c = slogan( ) ;
printf ( ”% d”, c ) ;
}
void slogan( )
{
printf ( ”Only He men use C!” ) ;
}
(c) main( )
{
void slogan( ) ;
int c = 5 ;
c = slogan( ) ;
printf ( ”% d”, c ) ;
}
void slogan( )
{
printf ( ”Only He men use C!” ) ;
}
12
PROGRAMMING with C[ERUCS 105]
14
![GITAM UNIVERSITY
(Declared as Deemed to be University U/S 3 of UGC Act, 1956)
Lecture Notes
of
Programming with C
[ERUCS 105]
INTRODUCTION
Lecture-1
Hyderabad Campus, Rudraram
HYDERABAD-502329
JULY-NOV 2013](https://image.slidesharecdn.com/lecture-1-130918020740-phpapp01/85/Lecture-1-1-320.jpg)
