1 00:00:03,630 --> 00:00:10,830 So before we write our first program there are some instructions we need to take a look at and we would 2 00:00:10,830 --> 00:00:16,620 look at the op codes we would use in our program for this first program. 3 00:00:16,620 --> 00:00:21,810 We need to be familiar with seven up codes and we're going to take a look at them now. 4 00:00:21,810 --> 00:00:26,070 The first one is to move up code the move operation. 5 00:00:26,070 --> 00:00:31,050 What it does is that it moves data within the process or without access in memory. 6 00:00:31,590 --> 00:00:37,620 And I say in fairness you should know about the move operation not all data can be moved by this particular 7 00:00:37,680 --> 00:00:38,850 operation. 8 00:00:39,030 --> 00:00:42,400 The move cannot move more than eight feet to follow you. 9 00:00:42,400 --> 00:00:47,350 Also the move cannot move to high registers. 10 00:00:47,370 --> 00:00:53,730 Remember when we created registers we demarcated them into lower registers and higher registers to move 11 00:00:53,760 --> 00:00:55,590 cannot move to higher registers. 12 00:00:55,590 --> 00:00:57,580 Let's see an example of this. 13 00:00:57,780 --> 00:01:01,940 Let's say you have this instruction move our 0 1 50. 14 00:01:01,950 --> 00:01:09,040 What this does is that it puts the value 150 in the register are zero. 15 00:01:09,180 --> 00:01:11,300 And this immediate value. 16 00:01:11,430 --> 00:01:16,500 And as we know 150 is within the 8 bit barrier. 17 00:01:16,530 --> 00:01:19,590 Let's take another look at this example. 18 00:01:19,680 --> 00:01:25,170 This another example also you can move one register into another. 19 00:01:25,170 --> 00:01:32,400 And what this does is that it moves the value of one register into the other and makes them equal in 20 00:01:32,400 --> 00:01:43,150 a sense move our one hour two gives us our 1 course are two copies the value of our R2 into our. 21 00:01:43,650 --> 00:01:46,210 This an incorrect example. 22 00:01:46,680 --> 00:01:54,090 Look at this for instance move our 0 2 5 6 and we know immediate value is out of range the largest number 23 00:01:54,090 --> 00:02:00,970 of 8 bits is 2 5 5 2 something like this would cause an era wouldn't work. 24 00:02:01,140 --> 00:02:06,480 Another incorrect example is move R eight. 25 00:02:06,540 --> 00:02:07,980 Number three. 26 00:02:08,100 --> 00:02:12,040 And as you can guess are eight is a high register. 27 00:02:12,240 --> 00:02:19,500 So we cannot use this instruction on a higher register and we cannot use this instruction with values 28 00:02:19,530 --> 00:02:20,910 greater than 8. 29 00:02:21,510 --> 00:02:31,200 The next instruction or OB code we're going to look at the LTE are and what this means is called register 30 00:02:31,680 --> 00:02:41,370 and what this does is it's loads register with either a 32 bit constant value or another register it 31 00:02:41,370 --> 00:02:50,460 reads a 32 bit volume from memory to register remember the move the one we just saw just moves in in 32 00:02:50,460 --> 00:02:58,230 the register it cannot access memory load on the other hand can access memory and it can access other 33 00:02:58,230 --> 00:03:01,810 values in the register as well. 34 00:03:02,520 --> 00:03:05,040 Let's take a look at this example. 35 00:03:05,280 --> 00:03:11,500 We have lowered our sero 0 x f f f this hexadecimal value. 36 00:03:11,520 --> 00:03:19,020 What this does is that it loads this value into our zero and this another example. 37 00:03:19,020 --> 00:03:21,000 It's a bit different from the first one. 38 00:03:21,060 --> 00:03:25,140 Load our icon square brackets are two. 39 00:03:25,210 --> 00:03:27,050 We've not treated pointers. 40 00:03:27,060 --> 00:03:28,580 I know. 41 00:03:28,920 --> 00:03:35,730 We'll talk about them when we start typing in stuff like I always say yes but this is to give you an 42 00:03:35,760 --> 00:03:42,170 overview so that when we type you just remember we did this and oh this is how it works. 43 00:03:42,180 --> 00:03:52,620 So what this means is the R1 is the value pointed to by our team the instruction load are 1 square brackets 44 00:03:52,700 --> 00:04:02,490 are two meaning point R1 to the value in which are to the value contained in R2 let's say R2 let's say 45 00:04:02,490 --> 00:04:09,810 R2 contains the value to 5 6 then our 1 starts point into 2 5 6. 46 00:04:09,950 --> 00:04:14,150 And yes I know I said 2 5 6. 47 00:04:14,160 --> 00:04:21,330 Remember we are using to load up code not move so to 5 6 would work with load but it wouldn't work would 48 00:04:21,330 --> 00:04:22,130 move. 49 00:04:22,170 --> 00:04:26,700 Remember this white 32 bit values whilst we move 50 00:04:35,920 --> 00:04:38,000 8 8 base values. 51 00:04:38,860 --> 00:04:40,980 Let's look at this other one. 52 00:04:41,350 --> 00:04:43,500 This is the store up code. 53 00:04:44,020 --> 00:04:48,760 And what this does is that it stores a register of value into memory. 54 00:04:48,760 --> 00:04:56,700 An example of this is to store our 0 1 stores the value of our 0 into our 1. 55 00:04:56,770 --> 00:04:58,670 Can you tell the difference. 56 00:04:58,870 --> 00:05:00,320 There is a bit of difference. 57 00:05:00,340 --> 00:05:03,500 It looks quite similar to the load. 58 00:05:03,600 --> 00:05:11,000 However if you look carefully at the comments here this one stores the value of our 1 into R2 and 2 59 00:05:11,530 --> 00:05:21,370 Sorry stores the value of our 0 into R1 the value of R1 into our 0 would to store the first register 60 00:05:21,730 --> 00:05:28,540 or the first operant is the source and the second operant is the destination register. 61 00:05:28,540 --> 00:05:33,910 This is the opposite for to load up code. 62 00:05:34,240 --> 00:05:41,770 So our one sorry our zero into R1 is towards the value of Irish you go into R1. 63 00:05:42,160 --> 00:05:50,710 If we replace this with load of the r zero our 1 0 0 is going to be the destination and our is going 64 00:05:50,710 --> 00:05:51,750 to be the source. 65 00:05:51,790 --> 00:05:53,210 So please do remember this. 66 00:05:53,230 --> 00:05:56,260 A lot of people get confused by this. 67 00:05:57,780 --> 00:06:02,350 And the next one instruction number for is to be instruction. 68 00:06:02,410 --> 00:06:05,840 What this means is branch to a location. 69 00:06:05,830 --> 00:06:12,340 An example of this is B loop and you should know this word loop is not a reserved word is a word that 70 00:06:12,400 --> 00:06:24,530 we give it could have been B turn on or b go b stop this one branches it branches two or jumps to loop. 71 00:06:24,750 --> 00:06:32,470 It's like there is a label in our program called Loop remember we said we put labels by our instructions 72 00:06:32,510 --> 00:06:34,970 so that we can access them easily. 73 00:06:34,990 --> 00:06:36,850 So there's a label somewhere called loop. 74 00:06:37,090 --> 00:06:39,880 If we invoke B loop we count the. 75 00:06:40,420 --> 00:06:44,230 And we would see an example of this when we stop right in the code. 76 00:06:44,300 --> 00:06:55,060 Now we have no five B L and this one is primes to a subroutine B L turn on cost to turn on and turn 77 00:06:55,060 --> 00:07:04,300 on this a subroutine that is different from the B and the says the the B jumps to 1 9 instructions. 78 00:07:04,430 --> 00:07:04,680 Yeah. 79 00:07:04,690 --> 00:07:11,130 To put it in simple terms it comes to an instruction location whereas this one comes to a subroutine 80 00:07:11,140 --> 00:07:17,540 you can think of a subroutine as a block of code perhaps like a function in a high level language. 81 00:07:17,710 --> 00:07:26,140 It goes to a series of operations not just one instruction it goes to series and then goes back so detail 82 00:07:26,200 --> 00:07:32,620 jumps to a subroutine and B comes to an instruction the location of an instruction. 83 00:07:32,620 --> 00:07:42,010 So we have the number six this is P x l ah yes get just abbreviations No we start typing them to start 84 00:07:42,010 --> 00:07:43,080 making more sense. 85 00:07:43,100 --> 00:07:43,370 Yeah. 86 00:07:43,390 --> 00:07:44,680 Just bear with me. 87 00:07:44,680 --> 00:07:52,060 This one returns the value from a subroutine core an example of this is let's say we have the subroutine 88 00:07:52,060 --> 00:07:54,290 called Blue on. 89 00:07:54,670 --> 00:08:04,480 So we move the value 0 x 0 1 which is the value one would move it into R2 and then be X L R meaning 90 00:08:04,570 --> 00:08:12,040 it returns the value to the function that was run in before jump into this subroutine its returns to 91 00:08:12,040 --> 00:08:13,300 value after its run. 92 00:08:13,300 --> 00:08:13,950 This code. 93 00:08:13,990 --> 00:08:19,210 It keeps the value of R2 when it goes back to where it's come from. 94 00:08:19,750 --> 00:08:20,750 Yes. 95 00:08:20,920 --> 00:08:27,730 So this one as you can tell would be used in conjunction with a b l mean and when you entered a subroutine 96 00:08:27,730 --> 00:08:34,100 and a subroutine does its processes and it gets a value you might want to take it back and then use 97 00:08:34,100 --> 00:08:41,770 that value and what you invoke is to be X L R returns from separate subroutine blue on. 98 00:08:41,950 --> 00:08:42,600 Yes. 99 00:08:42,700 --> 00:08:47,630 And this the last one this the N O P and it stands for no operation. 100 00:08:47,770 --> 00:08:57,220 Our do nothing assessors here for example Star 1 A.P. A.P. stores the value of r 0 into our 1 do nothing 101 00:08:57,220 --> 00:09:00,930 for 2 psychos 1 annual P of course one cycle. 102 00:09:00,940 --> 00:09:07,420 This is usually used for padding if you want to give perhaps you want to give time to some operation 103 00:09:07,420 --> 00:09:14,680 to perform in a jump to the next operation you can put it where a series of No operation no operations 104 00:09:14,710 --> 00:09:18,380 we would use it if we'll use this when we start. 105 00:09:18,500 --> 00:09:23,920 So these are the first seven up codes that we going to be using. 106 00:09:24,100 --> 00:09:28,480 The first of an instructions would have this in our program.