1
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Now we are going to step through the code and see the changes that go on in the register and memory.

2
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Before we do that let's take a look at what the various views are displaying.

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Now currently we have the logos view here showing our local variable counter showing this number 2 x

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1 0 0 0 0 6 0 and then we have here in the red just a view.

5
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Iris you are 1 2 and are 3 showing the same values stored in the local variable.

6
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Yes there's a random number we've not initialized a variable so that's a random number in it for us.

7
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And let's see here in the disassembly view we still have it here.

8
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As we mentioned the arrow is pointing to the beginning of the main function and we know the main function

9
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is where all problems start.

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What we see here and a code few this arrow pointing to this very line lane number four which is into

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county course you mean and we had to declare and initialize and count equals zero when the arrow was

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pointing to a line.

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It does not mean the line has executed but rather it means this is the line to be executed next.

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So now when we when we move a step when we move from this line to this line by number four to number

15
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five we would execute this line and logically or according to the rules of the compiler our local variable

16
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counter should be initialized the value 0.

17
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So we're going to step through the code one see line at a time and we're going to do it by clicking

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this I can hear.

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This is known as this step I can this I can show in a pair of candidate graces with umpire pointing

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and so let's click and see.

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So let's see the changes first of four in the code few.

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We see the it's dropped from line number four to line number five which means we've initialized that

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already.

24
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Let's see what happened in our registers we'd realized our 1 has changed to 0 x sera sera sera sera

25
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sera meaning the value is zero.

26
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And indeed in the disassembly if you realize it's dropped to this line remember this is where we started

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it's dropped here.

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And what what got executed in the disassembly view was moving the value 0 into register are 1.

29
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Remember we treated this in the previous chapter cortex and assembly the instruction move as are 1 0

30
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0 0 means put the value 0 into R1.

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That is why we have our once you are x sera sera sera sera sera sera sera sera sera sera sera.

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Are equal in value the same.

33
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In fact it's still equal to the decimal zero.

34
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If we check here in our local as you would see that the counter which is our local variable has to find

35
00:03:09,910 --> 00:03:14,400
you sue X you're serious you are zero the same value stored in Taiwan.

36
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So we we saw what happened in the disassembly if you will move divide value zero into our one and then

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when we check in the register or when we look into our register then we see that indeed everyone has

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zero since it's been moved to zero here.

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And when we check our variable here if we are to print it out it would print out the value 0 which we

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are doing here by using the locals view.

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In fact let's change this to display in decimal form we do it by right clicking here and on checking

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the hexadecimal display.

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Now it's here another important register I want to take note of as AR 15 which is P.S. the program counter

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when we see here in the register view we realized that the value of AR 15 has changed to 0 0 0 0 0 3

45
00:04:05,530 --> 00:04:13,360
9 see what it does is it stores the address of the next instruction to be executed.

46
00:04:13,360 --> 00:04:21,610
So let's go to the disassembly view and check whether indeed 0 0 0 0 3 9 C is the address of the next

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instruction to be executed.

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And as we know the yellow line is pointing to the next instruction to be executed and indeed the address

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is zero exterior seriously with 3 9 C..

50
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Let's iterate once more and see whether the rules we've just established follow through.

51
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Okay.

52
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Over here in the code for you it's dropped in line meaning we've just executed this instruction plus

53
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plus counter meaning counter plus one meaning in one to counter.

54
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So let's see what this means.

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Indeed disassembly Q which is basically the assembly code the code we executed is at 1 2 R1 This is

56
00:05:03,510 --> 00:05:07,320
it says here I want your course are one plus one.

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Meaning I'd want to R1 and then store it back into R1.

58
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And this is the art.

59
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Remember we said the art entered as art or art.

60
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In fact we said or did you want X or the goods.

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If you see s by the end it means updates are a register so don't worry a lot about the s.

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Just look at the art just like we had to move here.

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So we've added we've added 1 2 R1 and stored it back into our one and before we forget.

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Let's go to our low cost view and see whether indeed we have added one to the console variable which

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was 0 initially.

66
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Yes.

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And then we see here.

68
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Indeed we spotted one.

69
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Let's continue our iteration if I did another one I did another one.

70
00:05:58,000 --> 00:06:04,170
And P.S. It's telling us that the next instruction to be executed has the address ending with three

71
00:06:04,670 --> 00:06:07,980
a two and plus three two here.

72
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So basically this is how computers add.