Introduction to Computer Organization & Architecture (CAO) Video Lecture | Computer Architecture & Organisation (CAO) - Computer Science Engineering (CSE)

hello everyone this is Rahul from
learning simplified in this series of
tutorials we will learn computer
organization so let's get started the
word computer was derived from compute
early mathematicians weren't having any
computing devices as we have today we
have calculators and computers to
perform the automatic calculations but
in those days the mathematicians used
pen and paper to compute all the
necessary calculations such as if you
have a large number nine three four
seven two nine one times four seven
three nine one four if we want to
calculate the result of this they used
pen and paper to calculate so there was
a necessity to invent something which
can calculate these numbers on itself as
the Greek philosopher said necessity is
the mother of invention they have
devised an electronic they have made an
electronic device and called it as a
computer it was a processor processor
they came up with the processor which
can process all this information they
used to give input as the numbers and
they used to get the result as the
output from this processor but there was
something lacking in this they wanted it
to performs a task such that first it
has to perform one task say t1 then it
has to perform t2 then t3 without the
user intervention that is it has to
perform in this order let us say task
one is addition task two is division and
ask three is multiplication but the
processor wasn't capable of doing that
things because it had it did not have
any memory it yes it has been
in the form of registers but it is a
temporary and very less memory to store
this much huge information so they came
up with something called as a memory to
integrate with the processor memory and
this memory consists of various cells
these are cells where the memory is
stored each cell can store either a data
or an instruction that is addition
division multiplication and so on we
will see in the next future tutorials so
this memory is used to store the
information but there wasn't the
satisfaction with the among the
scientists so in where they invented the
further went forward and invented
something known as IO because they want
to interact directly with the processor
and get the result directly to them
instead of storing first in the memory
and the processor processes it and
stores the memory into the memory again
and looking into the memory for the
result that was also a tedious task for
us so this quotation perfectly suits our
everyou evolution of processor and
computer in this form what it does is
processor requests data from the memory
and memory accepts the request and gives
the data to the processor what IO does
is from the real where humans can
interact with the processor it can
directly give the input to the processor
and we get output directly from the
processor and we have memory as well so
this is the big picture of a computer in
the next upcoming tutorials we will see
more about processor memory
and IO in processor we see what are the
types of instructions that a processor
can handle everyone has their own
language likewise a computer also allow
or has a language with which it
understands if we want to say a
processor to add some add two numbers
then we have to give the instruction in
the format which the processor can
understand so we will deal with
instructions instructions and the
processor has to know where the data is
to process suppose it is at this cell
then the processor has to bring that
data from this cell so we will also deal
with the addressing addressing of data
in the processor itself and then then
comes to the memory we will know what is
a memory how the data is organized into
a memory I want to tell you something
here is the registers in the processor
are fast very fast compared to this
memory outside the process outside the
processor so in order to that the
processor calculates the information
very fastly but because this memory is
very slower the processor has to wait
until the data from here is fetched into
the processor so we have come up with
another idea again there is a necessity
here and necessity is the mother of
invention we came up with something
known as cache memory see ACH II cache
memory which lies in between a processor
and main memory what it does is it
stores some block of data and when
processor needs it it it gives the data
to the processor and processor processes
the data and stores back into the
cash at some point we will see that this
data is updated into the main memory
again at some point of time this is the
need for cash this is a bi-directional
this means this is the flow of data and
we can we also have a connection from
main memory to the processor as well
direct connection so we will we have to
look at cache memory and this memory
what in cat what to deal in cache memory
is a processor generates the address
with respect to the main memory but we
have a cache in between these two so we
have to map that address like this a
processor processor generates an address
an address which refers to the main
memory but we have to map this address
we have to map this address to cache
memory so that it can refer to the
correct data in the cache and process it
so we have three address mapping
techniques one is let me change the
color one is associative mapping
associate their next is set associative
associative
and the third is direct mapping direct
mapping and next after we have finished
the memory part we will deal with IO and
IO is any physical device that is
visible to the user suppose such as a
keyboard or a printer or an LCD screen
what how do we interact with the process
directly is when you press a key a key a
on the keyboard while you are on a word
document or some notepad what it does is
it check it takes the input and changes
this a into ASCII format ascii American
Standard Code for information
interchange so that the processor can
understand it processes this this data
and renders it on the LCD screen if we
have an LCD screen what it does is when
we press na it goes into the processor
an LCD screen has a large number of dots
or points where it can color each and
every point such that na can appear here
it colors like this
something like that to make an a appear
on this LCD screen it does it in that
way but in this course we are not going
to look at the memory I mean IO devices
we will deal with two important things
one is interrupt what is an interrupt is
as said here the processor performs
different tasks such as addition
multiplication it keeps on performing
the tasks when you press an a it has to
interrupt the processor to render that a
on to the LCD monitor so that is an
interrupt we are interrupting the
processor while it is doing some tasks
such as in a there are two to two types
of lecturers who give the lecture for
first 50 minutes they give the lecture
boring lecture for 50 minutes followed
by a 10 minutes doubt session if a
student gets a doubt here or here he has
to wait until the lecture gets finished
and he has to ask the doubts here but
there are other lecturers who make the
session more interactive this is an
interactive session if a student gets
heard out here he interacts the teacher
and teacher stops teaching what he is
teaching it is the doubt of the student
and he gets back to his teaching again
another student gets it out here
he asks again and Heather gets here he
asks again so let us see in this topic
how a processor handles the interrupts
and we will see one more thing
which is known as d-m a this stands for
direct memory access which means a
process this is to aid the processor a
processor is a very fast device in all
of these devices so when when a large
number set of data is to be transferred
from one location to other location a
processor is always involved in the
transfer which is a wastage of valuable
processor time in that time it can
compute other tasks so to overcome that
we have a DMA control what the what what
this does is the processor initiates the
DMA to take charge of data transfer when
the DMA takes charge of data transfer
the processor performs other tasks which
it has to perform when the data transfer
is complete the DMA gives back the
control to the processor and processor
becomes the king again so we in short we
are going to deal with all of these in
this subject I find many people having
difficult with the subject but I promise
I make it very easy by the end of this
course you will be very happy with this
course now how do we integrate all these
into a computer this was proposed by
John von Neumann which is family known
which is famously known as one Neumann
architecture it has a memory as you have
said this whole thing is a processor and
these are the i/o devices these are
connected with the help of bus this
thing is a bus which bus is nothing but
a set of wires that is used to connect
all the devices we will look in more
detail on about all these component
components in the future tutorials I
hope you have enjoyed the video see you
next time until then happy learning