MIPS Tutorial 15 Introduction to Functions Video Lecture | MIPS Assembly Programming Simplified - Electronics and Communication Engineering (ECE)

hello guys this is a melon and I'm very
excited today because I'm going to show
you how to make functions or procedures
in MIPS and this is a very important
topic first of all don't forget go to
smartphone your comm and well let's
start by making a new file new and then
save it to your desktop maybe maybe if
you want to your desktop and then the
name that I'm gonna give it is procedure
that ASM and save and now happen I have
a new file so type that data for the
data section that text for the for the
instructions section so what is a
function or what is that a procedure
okay a function or procedure is just
like a mini program inside your program
because programs are composed of many
components and those components are like
modules so you can think of them as
modules so those functions they are
reusable so you can just reuse them
whenever you want and how do you reuse
them well when you reuse them when you
use them you can use them as many times
as you want and that's called and that's
called calling a function if you call a
function you are using a function but
you have to make a function before you
can call it so right now I'm gonna show
you how to make a function and in Java
that color methods and C++ the color
functions but it makes people call it
procedures so I'm gonna say procedure
from now on so first of all I want to
make a message in random access memory
and this is a label right here this is
the name of the message but actually
technically this is a label so now that
that's the name so now I'm I need the
data type so the data type is just a
text or a string and then in quotation
marks I can write my message so it's
gonna be hi everybody
and then
I want a new line so I'm gonna do
backslash N and finally I'm gonna do
this right here
my name is AM L with uppercase right
there so right here another new line you
can see that I have a message in random
access memory so now I want to write a
code but before that I want to teach you
about labels so a label is just a name
with a colon and all the time whenever
you're making a function like or make
whenever you're making a program you
should make sure that you have a main
label because this is good practice
maying is like the main function the
main procedure or the main module in
your program the main component so I
want to make a function and this is the
main function right here it's a special
function but I also want to make another
function and this is gonna be called
display message so this is the name of
the function this is the name of the
procedure display message and this is
how I make a function I just write the
code then label are Co long and the code
so I just want to display display the
message and as I told you as I showed
you before in order to do that you do
loading media tell us I'm V 0 comma 4 to
display text on the screen then you do
load address the low sign in zero comma
message and finally you do Cisco so this
is going to display the text on the
screen all this right here but I also
want to do this line all the time
whenever making a function I want to say
jump register Dallas IRA and what this
is gonna do right here is that this is
going to go back to the function or the
place or the procedure that called it so
this is going to go back once this is
done so it's not gonna stay inside the
phone instead of proceeding
the procedure so before I use the
function you have to make sure that you
have this line of color here loading
media del assign B 0 comma 10 Cisco so
this is going to do the following this
is gonna tell the system that the
program is done so if you don't do this
line right here in Maine if you don't do
it right here um you're gonna have um
your computer is gonna be doing the same
stuff over and over again and it's not
gonna stop I mean it's gonna give you an
error when it stops because it's gonna
be doing infinite recursion it's gonna
be like calling itself pulling itself
all the time all the time cutting itself
so you this line is mandatory if you
want this to work so from now on get in
the habit of typing this line of code
these two these two instructions right
here to tell a system to tell the system
that the program is done so I have my
function right here my procedure display
message this is going to display the
message and then it's going to go back
to the caller so this is the colleague
the colleague procedure and Maeng is
going to be the color and the color
always in the color which is Meng or
main always needs a place to end the
program and this is how you tell me this
is the end of the program so now how do
you use the function or how do you use
the procedure well you have to do it
this way ja or jump in link and then the
target the target is gonna be the name
display message so what this is gonna do
right here is that it's going to jump to
this place right here to this function
and it's going to execute all the code
and finally it's going to return right
here it's gonna return to main so now
we're just gonna test it so save it run
a simple clear execute voila our
function is
working so hi everybody my name is amel
so it's working but now let me show you
if we didn't call the function if we
didn't call the procedure and we save
run a sample and then we execute you see
nothing nothing happened because if you
don't call the function this code will
never execute this code right here will
never execute so you have to call it if
you want to use it so let me show you
something else
so remember jumping link and the name of
the function and assemble execute and
you have the message right there so we
go to edit and right here let me show
you once the function is done you can do
more stuff you can do for instance more
code and it's going to execute as well
idreammedia dollar sign is s 0 comma
dollar sign zero comma 5 so I'm just
putting the value 5 right here in again
0 and then I can do the following write
load immediate Alice I'm V 0 comma 1 and
then add tell assign a zero dollar sign
zero comma dollar sign and 0 and then I
can do Cisco and this is gonna print
number five to the screen and if we save
and then run assemble and finally we
execute you can see the message was
printed and after the message was
printed number 5 is printed so this is
the code it's not very complicated it's
kind of simple so yeah whenever you call
a function whenever you're using a
function
you use jumpin link and this is going to
go to the function and it's going to
store the address the address is going
to school it's going to be stored in the
loss on our a in the register that
assign our a and this is the register
that I'm talking about this is return
address so this is going to be stored in
the loss hangar a so whenever you're
done using the function this is going to
go back to the to the address stored in
our in our a so this is the introduction
for you for functions and procedures
very interesting topic they are very
useful very important in computer
programming and that only emits but it
makes the very important because they
allow you to hide details to hide
details of implementation so I hope that
you enjoyed this tutorial I hope to see
you next time and well thank you for
watching