Assembly Langauge

1. Assembly language
PPT ( 1 )
Introduction AND
Basics

2. What is assembly language
 An assembly language is a low-level programming
language for microprocessors and other programmable
devices.
 It is the most basic programming language available
for any processor.
 A processor understands only machine language
instructions, which are strings of 1's and 0's.
 However, machine language is too obscure and
complex for using in software development , instead
low level assembly language is used .

3. Flow of compilation

4. Compilation flow explained
 Preprocessing : is the first pass of any C
compilation. It processes include-files, conditional
compilation instructions and macros.
 Compilation : is the second pass. It takes the
output of the preprocessor, and the source code, and
generates assembler source code.
 Assembly : is the third stage of compilation. It
takes the assembly source code and produces an
assembly listing with offsets. The assembler
output is stored in an object file.

5.  Linking : is the final stage of compilation. It takes
one or more object files or libraries as input and
combines them to produce a single (usually
executable) file. In doing so, it resolves references
to external symbols, assigns final addresses to
procedures/functions and variables, and revises code
and data to reflect new addresses (a process called
relocation).

6. Basic feature of PC hardware
 Motherboard : The motherboard serves
to connect all of the parts of a computer
together. The cpu, memory, hard drives,
optical drives, video card, sound card and
other ports and expansion cards all
connect to the motherboard directly or via
cables.

7. Motherboard explained

8.  BIOS :lowest-level software in the computer, acts
as an interface between the hardware and the
operating system .
 ROM : is nonvolatile. ROM chips contain
permanently written data, called firmware (your
BIOS lives here).
 RAM : RAM devices are used in computer
systems as the main memory. RAM is considered
volatile memory, which means that the stored
information is lost when there is no power.

9. Processing devices

10.  Control unit : A control unit (CU) handles all
processor control signals . It directs all input and
output flow, fetches code for instructions from
microprograms and directs other units and models
by providing control and timing signals.
 ALU : An ALU performs basic arithmetic and logic
operations. Examples of arithmetic operations are
addition, subtraction, multiplication, and division.
Examples of logic operations are comparisons of values
such as NOT, AND, and OR.
 Registers : In a computer, a register is one of a
small set of data holding places that are part of a
computer processor . A register may hold a
computer instruction , a storage address, or any kind
of data.

11.  Bus : The CPU moves data around the computer
on pathways that interconnect it to all the other
components on the motherboard. These pathways
are called 'buses‘
 Types of Bus
 Address - the components pass memory addresses
to one another over the address bus.
 Control - used to send out signals to coordinate and
manage the activities of the motherboard
components.
 Data - transferred between peripherals, memory and
the CPU. Obviously, the data bus can be a very busy
pathway.

12. Number system
 A set of values used to represent different quantities is known as
Number System
 Types of number system
1. Binary - Or base 2. There are only two numbers in binary, 0 and
1. Because computers use a sequence of switches that can be on
or off (also called a bit), base 2 works very well for them. Math
in base 2 is pathetically simple, but incredibly time consuming
2. Octal - Or base 8. Uses the numbers 0 to 7. There are eight bits
in a byte which is used very often in the computer field. (A bit is
great, but it's too small to hold any useful data, thus the byte is
used.) Math in octal is more complicated than decimal
3. Decimal - Or base 10. Uses the numbers 0-9. I'm sure you're
familiar with this system. Computers only display numbers in
decimal, they actually do all their work in binary. Math is quite
simple with this number system, although some may argue.
4. Hexadecimal - Or base 16. Uses the numbers 0-F. Yes, I said F.
Because there are 16 values per place holder, five new numbers
had to be created. Those numbers are A, B, C, D, E, and F
(Original isn't it?). "A" has a value of 10, "B" is 11, and so on

13. NUMBER SYSTEM
SYSTEM BASE DIGITS
BINARY 2 01
OCTA L 8 01234567
DECIMAL 10 0123456789
HEXADECIMAL 16 0123456789ABCDE
F