1 00:00:00,840 --> 00:00:01,340 Hello. 2 00:00:01,380 --> 00:00:02,290 Welcome back. 3 00:00:02,310 --> 00:00:09,150 In this lesson we're going to see how to develop a GP I O output drive up for a while Texas Instrument 4 00:00:09,400 --> 00:00:15,030 Tim for C one two three microcontroller board will create a new project by coming over here. 5 00:00:15,030 --> 00:00:17,010 Project New Vision project 6 00:00:20,080 --> 00:00:26,060 and then um I'm going to navigate to the um so for that to start my project 7 00:00:29,080 --> 00:00:31,150 I'm going to keep it over here. 8 00:00:31,690 --> 00:00:35,880 I call this GPO and then I'll save it. 9 00:00:35,890 --> 00:00:46,410 My board is t n for C team for C 1 2 3 0 8 6 p.m. and then okay. 10 00:00:48,930 --> 00:00:51,450 So like this and then I'll click Okay. 11 00:00:51,670 --> 00:00:58,690 And then on the Simpsons I select the core on a device I select the start up then I say okay. 12 00:00:58,720 --> 00:01:00,370 Over here. 13 00:01:00,400 --> 00:01:01,170 Right. 14 00:01:01,210 --> 00:01:08,950 So then this my project target just him for C so renamed this to him for C and then I'll drop down over 15 00:01:08,950 --> 00:01:09,240 here. 16 00:01:09,250 --> 00:01:18,690 Source group are renamed is to up then I'll add new file but new item I see that dot s file. 17 00:01:19,510 --> 00:01:21,740 I'll give it a name made right. 18 00:01:22,150 --> 00:01:30,040 So before we went before we're able to develop our drivers we would have to take a look at the data 19 00:01:30,040 --> 00:01:36,370 sheet and the um the reference module provided so that we can know the addresses of the various ports 20 00:01:36,460 --> 00:01:39,260 and on the other pair forms that we need. 21 00:01:39,640 --> 00:01:46,840 So if you're using common vision you can come to the book stop over here and then they provide us to 22 00:01:46,840 --> 00:01:52,250 provide us um device data books we can click this and see if it works. 23 00:01:52,330 --> 00:01:54,370 The last time I tried it it didn't work. 24 00:01:55,280 --> 00:02:00,480 Um it brings us to the s t microelectronics website. 25 00:02:00,700 --> 00:02:02,380 Windows Explorer has crashed. 26 00:02:03,160 --> 00:02:05,340 Um anyway I suspect this doesn't work. 27 00:02:05,680 --> 00:02:12,560 So what I'm gonna do is I'm going to go to Google and find the um they use a module as well as the data 28 00:02:12,560 --> 00:02:13,690 sheet. 29 00:02:13,690 --> 00:02:18,640 For those of you who office in the S M 32 version of this course you realize that we were able to get 30 00:02:18,670 --> 00:02:21,390 access to those documents from this side here. 31 00:02:21,400 --> 00:02:24,190 It's not the same for Texas Instruments if not updated. 32 00:02:24,250 --> 00:02:26,740 So we have to find out from the Internet. 33 00:02:26,740 --> 00:02:40,790 I'm going to open my my search and I'm going to start off by search and time for C 1 2 3 to 4 C use 34 00:02:40,810 --> 00:02:41,380 a manual 35 00:02:47,240 --> 00:02:48,250 and. 36 00:02:49,610 --> 00:02:50,220 Okay. 37 00:02:50,310 --> 00:02:50,790 This appeal. 38 00:02:50,800 --> 00:02:51,060 Yeah. 39 00:02:51,100 --> 00:02:52,450 Yeah. 40 00:02:52,450 --> 00:02:57,160 No no S T C Series lunch but I'm gonna open this 41 00:03:02,210 --> 00:03:09,930 and I'm going to save it. 42 00:03:10,050 --> 00:03:12,090 This is the TVC use of my new 43 00:03:15,490 --> 00:03:16,690 I call this. 44 00:03:16,690 --> 00:03:21,620 You can say that on your computer at cost. 45 00:03:21,680 --> 00:03:25,430 If you have the board you would need this document right. 46 00:03:27,130 --> 00:03:27,560 Okay. 47 00:03:27,560 --> 00:03:29,480 And went to fetch another documents. 48 00:03:29,540 --> 00:03:32,490 This time I'm going to get the data sheet. 49 00:03:32,720 --> 00:03:37,370 I'll just change this to words use a mind or here to a single word data sheet 50 00:03:45,070 --> 00:03:53,360 and we have this other document to the SCC we still foresee key age 6 p.m. okay. 51 00:03:53,410 --> 00:04:00,750 This is it open in another tab and it s got over 1000 pages. 52 00:04:00,760 --> 00:04:02,410 This the data sheet. 53 00:04:03,030 --> 00:04:04,260 I'll save this as well. 54 00:04:07,590 --> 00:04:09,700 Team 4 C 1 2 3 55 00:04:12,880 --> 00:04:15,700 data sheet. 56 00:04:15,970 --> 00:04:16,480 Right. 57 00:04:18,920 --> 00:04:22,620 So I'm going to close this no. 58 00:04:23,090 --> 00:04:23,590 Right. 59 00:04:23,980 --> 00:04:25,830 So let's open the documents. 60 00:04:25,840 --> 00:04:27,910 We download it. 61 00:04:28,120 --> 00:04:29,410 I've got them here. 62 00:04:29,530 --> 00:04:33,300 So I've got to use a manual here and then I've got a data sheet. 63 00:04:33,310 --> 00:04:35,460 Let's take a look at the um the user manual. 64 00:04:41,050 --> 00:04:46,450 Um I'm going to take a look at this schematic diagram of the T4 seaport cause I want to know where our 65 00:04:46,460 --> 00:04:48,200 edit LCD connected. 66 00:04:48,220 --> 00:04:58,060 We are going to use our our GP LCD for our experiment right here on the page number on the page number 67 00:04:58,060 --> 00:04:58,350 four. 68 00:04:58,360 --> 00:05:03,220 We have an overview of the port showing the various components we have on the board. 69 00:05:03,280 --> 00:05:04,310 We've got the power here. 70 00:05:04,330 --> 00:05:06,960 We've got this microcontroller for debugging. 71 00:05:06,970 --> 00:05:09,110 This is our main microcontroller. 72 00:05:09,160 --> 00:05:12,370 We've got our Archie B LCD over here. 73 00:05:13,120 --> 00:05:19,920 And then we've got to to use our switches that we're going to use for our experiment as well. 74 00:05:20,020 --> 00:05:26,560 Then we've got USP here for those of you who want to develop USPTO devices right. 75 00:05:26,790 --> 00:05:29,780 But we'll we're truly interested in is down here. 76 00:05:29,980 --> 00:05:31,180 Page number 40 77 00:05:34,440 --> 00:05:40,010 I just go to 40 by searching over here. 78 00:05:40,060 --> 00:05:45,450 It's gonna 40 says it's gonna page number 40 sorry. 79 00:05:45,760 --> 00:05:48,230 I think it's page number 20. 80 00:05:48,300 --> 00:05:48,610 Skip. 81 00:05:48,760 --> 00:05:49,150 Okay. 82 00:05:49,180 --> 00:05:49,470 Yeah. 83 00:05:49,480 --> 00:05:50,110 Here we go. 84 00:05:50,740 --> 00:05:51,970 Okay. 85 00:05:52,480 --> 00:05:53,410 I'm going to zoom in 86 00:05:56,730 --> 00:05:58,700 and over here we have our LCD. 87 00:05:58,710 --> 00:06:06,980 We have we have our GP so we have Red Queen blue LCD and they are connected. 88 00:06:07,200 --> 00:06:13,020 Let's see if we can find the connection we want to see which pins they are connected to the microcontroller. 89 00:06:13,050 --> 00:06:13,560 Okay. 90 00:06:13,600 --> 00:06:15,230 This is the bit that talks about. 91 00:06:16,920 --> 00:06:17,160 Okay. 92 00:06:17,190 --> 00:06:26,940 So it seems our user buttons and melodies are all connected to port f f you is connected to this switch. 93 00:06:26,940 --> 00:06:35,670 Number two if one is connected to the red LCD P F two is connected to the blue LCD P if three is connected 94 00:06:35,670 --> 00:06:40,140 to the green LG P F four is connected to the switch number one. 95 00:06:40,320 --> 00:06:48,060 So we find this information at page number 20 of the user my new winner take note I'm gonna just put 96 00:06:48,060 --> 00:06:50,900 some notes here I'm just taking a step by step. 97 00:06:51,100 --> 00:06:57,570 So I just put this board and I hope I know nothing about it this is how I'll go about to write my first 98 00:06:57,570 --> 00:07:03,990 assembly driver or first go to the user manual to see how the power flows out connect to see how the 99 00:07:03,990 --> 00:07:13,040 arm to see how things like the LCD and other test test component are connected and then I'll take note 100 00:07:13,890 --> 00:07:21,790 and I will just take note by writing a comment this is what I do in my professional life I see um LCD 101 00:07:21,840 --> 00:07:26,100 red as we saw this is Pier 1 102 00:07:29,040 --> 00:07:37,140 we saw the switch one off switch to SPF 0 0 just call this Toby 2 This was PFC row 103 00:07:41,160 --> 00:07:47,700 and then little green SPF 2 104 00:07:56,140 --> 00:08:00,020 reality blue SPF 3. 105 00:08:04,290 --> 00:08:06,390 And then we had to switch one 106 00:08:09,190 --> 00:08:10,550 which was Pier 4. 107 00:08:11,320 --> 00:08:11,640 Okay. 108 00:08:11,680 --> 00:08:17,990 So these are the components we have we can test both GPL you input and output with the LCD and the switches 109 00:08:18,470 --> 00:08:19,000 right. 110 00:08:19,030 --> 00:08:20,450 And we know where to find them. 111 00:08:20,470 --> 00:08:24,320 They're all input F right. 112 00:08:24,340 --> 00:08:26,710 So we know to write what you tell your driver. 113 00:08:27,610 --> 00:08:31,990 Um to to sort of use our Elegy for our GPL you experiment. 114 00:08:31,990 --> 00:08:39,700 We need to access GPL you put F and couldn't figure out the registers that relates to the particular 115 00:08:39,740 --> 00:08:40,890 entity we want to talk. 116 00:08:41,090 --> 00:08:42,460 We want to Tokyo. 117 00:08:43,250 --> 00:08:45,980 So we need to find those registers before we do that. 118 00:08:45,970 --> 00:08:54,490 I have to give you a quick overview of how how modern day microcontrollers are designed and so modern 119 00:08:54,490 --> 00:09:00,840 day microcontrollers um are different in what in many ways from auto microcontrollers. 120 00:09:00,850 --> 00:09:06,480 One of these ways is in the mix and what is known as the implementation of the club gating mechanism 121 00:09:07,180 --> 00:09:14,830 and what this means is the clock access to various parts or you can call its various modules or you 122 00:09:14,830 --> 00:09:21,520 can still call its various peripherals so if the board block access to these various parts are blocked 123 00:09:21,730 --> 00:09:23,080 by default. 124 00:09:23,080 --> 00:09:26,340 So if I take my microcontroller proc access to GPL you. 125 00:09:26,350 --> 00:09:27,420 It doesn't exist. 126 00:09:27,460 --> 00:09:34,330 It is closed clock access to you can you be this close clock access to ATC clearance clock access to 127 00:09:34,330 --> 00:09:36,830 you are disclosed et cetera. 128 00:09:37,150 --> 00:09:39,080 This is known as clock gate. 129 00:09:39,160 --> 00:09:44,650 And what this does is this this sort of makes the Metro controller consume less power. 130 00:09:45,010 --> 00:09:53,620 And this is done because because the um the clock access is close by default you only enable or allow 131 00:09:53,620 --> 00:10:00,460 clock access to the parts that you want to use so that you don't just allow clock access to the entire 132 00:10:00,460 --> 00:10:00,940 board. 133 00:10:01,190 --> 00:10:01,660 Yes. 134 00:10:01,750 --> 00:10:05,160 Enable clock access to the parts that you want to use. 135 00:10:05,170 --> 00:10:14,410 So in this lesson we are going to use Port F because our output is connected to port F to port f we 136 00:10:14,410 --> 00:10:18,750 need to enable clock access to port F right. 137 00:10:19,420 --> 00:10:27,640 So um yeah we need to enable clock access to port F and then once we enable clock access to port f we 138 00:10:27,640 --> 00:10:35,540 can uh we can Togo the um their respective um port f registers. 139 00:10:35,560 --> 00:10:42,160 We can talk out the right registers in now that to configure port f us be the input output. 140 00:10:42,450 --> 00:10:42,890 Right. 141 00:10:45,470 --> 00:10:52,580 Now to enable clock access to a particular module and also I should mention in this course when I use 142 00:10:52,580 --> 00:10:59,390 the word module part and peripheral they mean the same thing I'm going to be using them interchangeably 143 00:11:00,250 --> 00:11:05,120 um paraphrase is much more specific as you would know about when I say module or parts. 144 00:11:05,210 --> 00:11:07,750 I'm just trying to see a particular unit. 145 00:11:08,020 --> 00:11:09,400 Right. 146 00:11:09,550 --> 00:11:09,820 Yeah. 147 00:11:11,810 --> 00:11:20,660 So to see how to enable clock access for a particular module um we have to decide on which bus to use 148 00:11:21,380 --> 00:11:25,750 generally in um quote X M architecture idea two types of buses. 149 00:11:25,850 --> 00:11:34,970 We have the AP bus and the HP bus the AP bus stands for Advanced peripheral bus and the HP bus stands 150 00:11:34,970 --> 00:11:37,700 for iPhone's high performance bus. 151 00:11:37,790 --> 00:11:44,540 The difference between the two is that the high performance one the HP allows for faster access to pay 152 00:11:44,550 --> 00:11:45,220 for those 153 00:11:48,320 --> 00:12:01,110 so as I was saying the um the HP I'm sorry that I had to replace my my headphones it got broken so as 154 00:12:01,110 --> 00:12:07,590 all saying we've got HP and AP bus and HP allows for a faster access to peripherals. 155 00:12:07,740 --> 00:12:15,600 So for instance if you use an HP bus to access a GPL you peripheral it might take let's say just two 156 00:12:15,600 --> 00:12:24,680 clock cycles to access it but if you want to access the same profile through APB you might need four. 157 00:12:24,900 --> 00:12:30,800 So HP could give you two and then APB would require four cycles to do the this is just an example. 158 00:12:30,810 --> 00:12:36,360 It's not specific anyway let's go to the data sheet to see a block diagram of our board and see how 159 00:12:36,360 --> 00:12:42,150 the HP an APB bus connects to the various peripherals of the board. 160 00:12:42,150 --> 00:12:46,350 I'm gonna go to the data sheets that we downloaded over here. 161 00:12:46,350 --> 00:12:48,200 There should be a block diagram somewhere. 162 00:12:48,450 --> 00:12:52,050 All of the data sheets have them. 163 00:12:52,450 --> 00:12:56,980 See. 164 00:12:57,640 --> 00:12:58,420 Sorry about that 165 00:13:02,160 --> 00:13:09,480 so um getting familiar with the data sheet is um so requirement for anyone who wants to take embedded 166 00:13:09,480 --> 00:13:15,120 development seriously you would have to get used to the data sheet and try. 167 00:13:15,270 --> 00:13:18,020 Um begin to like it essentially. 168 00:13:18,420 --> 00:13:25,380 Um once you understand the data sheets you can sort of rewrite the entire library of a particular board 169 00:13:25,470 --> 00:13:28,700 and get the most out of the port if you may. 170 00:13:28,730 --> 00:13:29,110 Right. 171 00:13:29,160 --> 00:13:33,710 Mr. block diagram we're looking for you can find this on page number 48. 172 00:13:33,730 --> 00:13:34,790 It's a 48. 173 00:13:34,800 --> 00:13:36,850 Yes it is 48 of the data sheet. 174 00:13:38,010 --> 00:13:38,720 Okay. 175 00:13:39,630 --> 00:13:44,140 So this is the um uh microcontroller high level block diagram. 176 00:13:44,310 --> 00:13:50,670 We have the E P B bus here and then we have the HP bus when you see this arrow. 177 00:13:50,700 --> 00:13:53,490 It means the particle profile connects to this bus. 178 00:13:53,490 --> 00:13:57,290 For instance the ATC connects to the APB bus to kill you. 179 00:13:57,290 --> 00:13:58,940 It also connects to the AP bus. 180 00:13:58,980 --> 00:14:05,130 So to use this you need to enable clock access of the eight through the APB bus. 181 00:14:05,200 --> 00:14:06,850 Right. 182 00:14:06,930 --> 00:14:10,680 General Purpose time it connects to the AP bus. 183 00:14:10,680 --> 00:14:13,600 Watchdog time is connect to the APB bus as well. 184 00:14:13,650 --> 00:14:20,280 Okay but what brought us here is the GPA you we have that you pay you for the GPL you they connect to 185 00:14:20,280 --> 00:14:22,560 both the HP and the APB. 186 00:14:22,560 --> 00:14:24,420 That is why we have two areas here. 187 00:14:24,420 --> 00:14:25,580 One for HP. 188 00:14:25,590 --> 00:14:31,680 Another one for APB so we can we can um we can use any bus we want for the GPL. 189 00:14:31,710 --> 00:14:37,200 But in our experiment we're going to use the default which is the APB connection. 190 00:14:37,400 --> 00:14:38,670 Right. 191 00:14:38,760 --> 00:14:39,900 So that's what we gonna do. 192 00:14:42,970 --> 00:14:43,440 Okay. 193 00:14:43,460 --> 00:14:48,690 Now on that we know the um the bus is available for access and the pair. 194 00:14:49,400 --> 00:14:52,130 We have to take a look at the registers of the peripheral. 195 00:14:52,130 --> 00:14:59,200 We are working with and then um also over here I have to give a short um short explanation. 196 00:14:59,270 --> 00:15:06,930 So um microcontrollers regardless of silicon manufacturer and regardless of architecture what eight 197 00:15:06,970 --> 00:15:16,490 sixteen bits 32 bits a microcontrollers all microcontrollers when you are dealing with the GPL you should 198 00:15:16,490 --> 00:15:21,260 have at least two registers and I know if you've seen the theoretical lesson I may have mentioned this 199 00:15:21,260 --> 00:15:22,040 already. 200 00:15:22,040 --> 00:15:23,600 They should have at least two registers. 201 00:15:23,600 --> 00:15:27,840 One is called the direction register and one is the data register. 202 00:15:28,010 --> 00:15:35,630 We use a direction register to set the GPL you as are inputs or outputs the data register is where the 203 00:15:35,690 --> 00:15:42,590 data is stored if it's output we write the data to the data register if it's input we read the data 204 00:15:42,740 --> 00:15:44,590 from the data register. 205 00:15:44,900 --> 00:15:46,080 Right. 206 00:15:46,090 --> 00:15:51,930 Apart from these two registers you would have optional registers that are useful things like decide 207 00:15:51,960 --> 00:15:58,400 into whether the pin should serve as an alternate function pane and then digitally enable in the pen 208 00:15:58,430 --> 00:16:03,860 or on the locally and enabling the pin cetera but a two man registers are the data in the direction 209 00:16:03,860 --> 00:16:05,000 register. 210 00:16:05,000 --> 00:16:05,330 Right. 211 00:16:05,780 --> 00:16:17,540 So far here in um in the architecture registers of the peripheral are often arranged as offsets from 212 00:16:17,540 --> 00:16:18,820 a base address. 213 00:16:20,490 --> 00:16:29,900 So in order to sort of find the register of a particular pair for let's say GPL you a GPL you a must. 214 00:16:29,950 --> 00:16:36,000 It's like the Register saying GPL you e are of the same type of state register as in GPL you'll be in 215 00:16:36,000 --> 00:16:43,640 the of the same type as registered some GPL you see of the same type as registers and GPL your D etc.. 216 00:16:43,710 --> 00:16:50,790 And because of this it's designed such that there is just a single address for GPL you e and then the 217 00:16:50,790 --> 00:16:56,490 GPL you register as such as GPL you a direction register is an offset from that single base address 218 00:16:56,490 --> 00:17:05,100 of GPL you e and GPL you a data register is another offset from the base address of GPA a such that 219 00:17:05,520 --> 00:17:13,140 the offset of the various types of registers the offsets are the same so wherever you are looking for 220 00:17:13,200 --> 00:17:20,770 direction register you can have the offset to be zero x2 1 and then when you are using looking for data 221 00:17:20,790 --> 00:17:29,550 register you can have the offset to be 0 x 3 2 but how we know that this data register belongs to GPL 222 00:17:29,550 --> 00:17:38,720 you e not GPL you see is that to get a complete address of lessee GPL you a data register you've got 223 00:17:38,710 --> 00:17:46,100 to take the bass address of GPL you e and you add the offset and because the various peripherals GPL 224 00:17:46,230 --> 00:17:53,310 a b c d etc. Do they have different base address they have their own base addresses so even if the offset 225 00:17:53,370 --> 00:17:59,850 of the various registers are the same because they have different base addresses we can be able to identify 226 00:17:59,880 --> 00:18:06,300 that this particular data register belongs to GPL you e this particular direction register it belongs 227 00:18:06,300 --> 00:18:12,510 to GPL you e etc. so without talking much less writes this less continue clued in you understand what 228 00:18:12,510 --> 00:18:12,890 I mean. 229 00:18:14,100 --> 00:18:17,790 So I'm gonna go back to the data sheet and I'm going to go to a page. 230 00:18:17,790 --> 00:18:23,250 I'm gonna go to Page 92 to find what is known as the memory model and this would give me the base address 231 00:18:23,340 --> 00:18:24,910 of my peripherals. 232 00:18:25,170 --> 00:18:29,000 So let's go to the data sheet. 233 00:18:29,460 --> 00:18:32,580 I'm gonna search 92 over here. 234 00:18:32,910 --> 00:18:39,300 It says memory module here and this keeps the base address so GPL you a base addresses this. 235 00:18:39,310 --> 00:18:40,520 It starts from here. 236 00:18:40,560 --> 00:18:42,180 It ends here. 237 00:18:42,180 --> 00:18:44,490 So the base address that that's what we need. 238 00:18:44,490 --> 00:18:46,810 So I'm gonna copy this. 239 00:18:47,290 --> 00:18:47,770 Sorry 240 00:18:51,270 --> 00:18:51,790 Grinch. 241 00:18:51,790 --> 00:18:54,560 Copy this and then I'll keep. 242 00:18:54,610 --> 00:19:01,660 I'll take note the call this GPL your APIs 243 00:19:05,230 --> 00:19:08,560 or delete the dot here right. 244 00:19:09,770 --> 00:19:12,890 So we have the base address. 245 00:19:12,890 --> 00:19:19,670 Another thing we need is the um system control base address system control is what we going to we're 246 00:19:19,670 --> 00:19:26,930 going to go through the system control to enable clock access for the entire GPL you um peripheral. 247 00:19:27,020 --> 00:19:33,250 So I'm going to fetch the system control piece address as well. 248 00:19:33,370 --> 00:19:38,470 Let's see. 249 00:19:38,720 --> 00:19:41,330 We should have this somewhere. 250 00:19:41,390 --> 00:19:42,200 Y is 251 00:19:54,000 --> 00:20:03,870 okay so if we want to o just point this out if we want to access GPL you e through the E HP bus we would 252 00:20:03,870 --> 00:20:10,530 have to use this other base address but because we accessing it through the default which is the APB. 253 00:20:10,530 --> 00:20:23,580 That is why I took the first address to this I know the address but it says HB here right. 254 00:20:24,080 --> 00:20:24,510 Right. 255 00:20:24,510 --> 00:20:28,220 If we cannot find the um the address on the table is fine that s another way. 256 00:20:29,490 --> 00:20:33,900 So when we go to the page that talks about the um the particular module it s right. 257 00:20:33,900 --> 00:20:37,860 The um what we call it it s gives us the address of the module. 258 00:20:38,250 --> 00:20:46,260 So let's go to the clock Kate and register and see the address written that the clock gate and um it 259 00:20:46,260 --> 00:20:57,930 s code the RC GC RC GC So just go to the top of the data sheet and search RC gc um RC DC. 260 00:20:59,220 --> 00:20:59,520 Okay. 261 00:20:59,550 --> 00:21:05,670 So this is a RC GC GP I O O click this and then let's see 262 00:21:10,600 --> 00:21:12,690 okay so that's the base address. 263 00:21:12,700 --> 00:21:14,260 It keeps us the base address too. 264 00:21:14,980 --> 00:21:15,670 And this is good. 265 00:21:15,670 --> 00:21:23,950 In other um in other documentations such as the um that of s t microelectronics when you go to the page 266 00:21:23,950 --> 00:21:26,040 that talks about a particular peripheral. 267 00:21:26,110 --> 00:21:28,270 It talks only about the. 268 00:21:28,330 --> 00:21:29,500 It gives you just the offset. 269 00:21:29,520 --> 00:21:34,600 It's expected to go to the um the table we're going to to fetch the uh the base address. 270 00:21:34,910 --> 00:21:37,340 But over here it keeps the base address as well. 271 00:21:37,570 --> 00:21:43,450 So we're going to use this to exit uh to a neighbor clock access and we can read more about it before 272 00:21:43,450 --> 00:21:44,170 I copy this. 273 00:21:44,170 --> 00:21:46,170 Oh sure you can. 274 00:21:46,390 --> 00:21:51,430 So it is called the general purpose input output run mode. 275 00:21:51,430 --> 00:21:52,860 Clock age in control. 276 00:21:53,740 --> 00:21:56,080 So this is this sort of closes. 277 00:21:56,090 --> 00:22:04,570 This is the gate clock gate to the GPL you and we can readable bits number five over here and you can 278 00:22:04,570 --> 00:22:07,530 simply come over here and read about the Spitzer number five. 279 00:22:07,530 --> 00:22:13,260 It says GPL puts f run mode locating control value description. 280 00:22:13,330 --> 00:22:20,640 Def zero GPL you put F is disabled if one enable and provide cloak to GPL you put F in run mode. 281 00:22:20,890 --> 00:22:27,960 So we would have to write we would have to write 1 2 bits 5 of this register here. 282 00:22:28,090 --> 00:22:29,410 So I'm going to copy the register 283 00:22:35,410 --> 00:22:36,860 right. 284 00:22:37,150 --> 00:22:43,590 And then um oh take note this is the base address actually belongs. 285 00:22:43,600 --> 00:22:50,320 It is for something um is for a structure known us says control so I'm going to call this this control 286 00:22:50,320 --> 00:22:56,950 base cos this uh the other the other members of the CIS control. 287 00:22:57,040 --> 00:23:00,880 So um perhaps perhaps I should just show you this. 288 00:23:00,880 --> 00:23:02,420 So this is how it is written. 289 00:23:02,480 --> 00:23:09,880 If if if we're going to write um let's say the um the complete Dreyfus from ground up professionally 290 00:23:10,270 --> 00:23:17,560 if we're going to write it to look like the CMC s um the CMC is written drivers we're going to write 291 00:23:17,560 --> 00:23:18,730 it in a structure form. 292 00:23:18,940 --> 00:23:23,800 So it's C language it would look like something like it would look something like this struct and then 293 00:23:23,800 --> 00:23:29,550 instruct I might probably have I I probably have um 294 00:23:33,150 --> 00:23:48,280 I may probably have GPL you RCC our GC right and then I probably have g p t m RCC and then I might probably 295 00:23:48,280 --> 00:23:55,570 have component 3 comp 3 and then comp for something like this 296 00:23:58,860 --> 00:24:00,790 and then I'll come here and give it a name 297 00:24:03,550 --> 00:24:04,870 something like Cisco control 298 00:24:12,030 --> 00:24:12,510 like this 299 00:24:16,020 --> 00:24:20,260 sorry for the look at the kind of spill control. 300 00:24:20,260 --> 00:24:22,030 So so that's the base. 301 00:24:22,350 --> 00:24:28,020 The reason why we keep talking about base address and offset is to get a complete address of this member 302 00:24:28,020 --> 00:24:29,300 here and these members. 303 00:24:29,370 --> 00:24:31,400 Yeah just yeah just registers. 304 00:24:31,410 --> 00:24:35,760 So let's say I want to get a complete address of this has to be the address of the base which is the 305 00:24:35,760 --> 00:24:39,580 structure the address of the structure plus the address of the member. 306 00:24:39,630 --> 00:24:41,070 Right. 307 00:24:41,160 --> 00:24:47,010 So this address that would just fetch our C GC belongs to a structure in no system control. 308 00:24:47,010 --> 00:24:51,550 That is why I've given it the name system control base here and all of it GPL you. 309 00:24:51,570 --> 00:24:59,050 This can be GPL you GPL you a it's the same way and we're going to have direction right yes the data 310 00:24:59,090 --> 00:25:05,520 so enable register data register etc. This is how it looks if you want to view it in the form of a data 311 00:25:05,520 --> 00:25:05,930 structure. 312 00:25:05,940 --> 00:25:11,790 So to get the address or direction register we've got to take the base address plus the offset here 313 00:25:12,060 --> 00:25:17,730 to get the address uh the address of digital enabled register we've got to take the base address plus 314 00:25:17,760 --> 00:25:19,060 the offset. 315 00:25:19,070 --> 00:25:20,200 Right. 316 00:25:20,280 --> 00:25:27,360 Anyway so we've got system control base and then there's the IP address of the base. 317 00:25:27,360 --> 00:25:27,690 Right. 318 00:25:27,690 --> 00:25:32,870 So let's see the offset for the RCC it gives us the offset here. 319 00:25:32,880 --> 00:25:40,130 That's the offset of RCC um offset of I Richie I see GC. 320 00:25:40,260 --> 00:25:45,390 I keep saying RCC because in SDM microelectronics it is called the RCC. 321 00:25:45,390 --> 00:25:52,430 So I'm going to take this sort of what the goodness to copy is you. 322 00:25:52,470 --> 00:25:54,540 X 6 0 8 323 00:26:01,690 --> 00:26:05,610 0 x 6 0 8. 324 00:26:05,620 --> 00:26:05,900 Okay. 325 00:26:06,100 --> 00:26:11,760 So now let's construct the RCC register to construct the RCC register. 326 00:26:12,610 --> 00:26:17,650 What I'm gonna do is to improve readability I'm going to do this step by step I'm going to first create 327 00:26:17,650 --> 00:26:27,700 a symbolic name for the base address or two Ss control and it's called base and I use the Q you directive 328 00:26:28,630 --> 00:26:41,320 and then I just assign this hexadecimal number here and then next I'll say I will C G C G P I 0 offset 329 00:26:42,400 --> 00:26:47,160 and we know it already this the offset the offset for our GC GPA you. 330 00:26:47,440 --> 00:26:54,040 So if we take the base and then we add the offset we get the complete address for this register. 331 00:26:54,040 --> 00:26:55,660 So this 332 00:26:59,550 --> 00:27:04,960 this I'll say it to you and then I'll pass the base that we got so x 6 0 8. 333 00:27:04,990 --> 00:27:08,360 Let's confirm it's the same as your x 6 or 8. 334 00:27:08,430 --> 00:27:15,130 So now to get the address I'm simply going to say since I'm going to use this naming convention and 335 00:27:15,130 --> 00:27:19,740 I'll explain why that is later I'll say says control 336 00:27:22,860 --> 00:27:29,940 R C G C G P I O underscore r e q u 337 00:27:33,650 --> 00:27:43,180 and this is simply a course system control base plus the offset. 338 00:27:43,230 --> 00:27:45,020 Simple as this. 339 00:27:45,210 --> 00:27:50,580 The reason I've decided to call this this registered this I could have used a shorter name. 340 00:27:50,640 --> 00:27:51,920 I could afford it. 341 00:27:51,920 --> 00:27:54,670 I could have called it Rick 1 or rec 2. 342 00:27:54,690 --> 00:27:56,260 All my. 343 00:27:56,310 --> 00:28:01,200 I could have given it any name in a symbolic name but the reason I'm using this as a figure to write 344 00:28:01,260 --> 00:28:08,910 this code in bare metal embedded to see you're going to use this same um the same naming convention 345 00:28:08,940 --> 00:28:14,090 if you use only Texas Instruments library you would see that there's a register that is called this. 346 00:28:14,130 --> 00:28:20,490 If you use this naming convention if I use under CMC this library provided by um you see that the naming 347 00:28:20,490 --> 00:28:21,990 convention is like this. 348 00:28:22,220 --> 00:28:23,800 I'm showing what I mean. 349 00:28:23,890 --> 00:28:30,270 I remember when I told you it's a structure in a member relationship with a base address and the offset. 350 00:28:30,270 --> 00:28:36,920 If I'm to get access to this register in my bare metal programming for those of you who have taken them 351 00:28:36,940 --> 00:28:41,320 met the bare metal um version of this course you would understand what I mean. 352 00:28:41,340 --> 00:28:44,210 But if you haven't this explanation should suffice. 353 00:28:44,220 --> 00:28:52,800 If I'm too if I want to access this register in C language or simply say SAS control and it's written 354 00:28:52,800 --> 00:28:55,070 seize control of put an R here. 355 00:28:56,190 --> 00:28:58,450 Yeah I think it's gonna hurt. 356 00:28:58,970 --> 00:28:59,970 We're gonna eliminate the. 357 00:28:59,990 --> 00:29:01,650 Ah yeah. 358 00:29:01,760 --> 00:29:02,820 It's written says control. 359 00:29:02,830 --> 00:29:03,700 That's the name they use. 360 00:29:03,720 --> 00:29:09,650 And then they use the arrow operator to access the RC GC GP. 361 00:29:09,790 --> 00:29:13,060 I remember and then I can assign my number here. 362 00:29:13,260 --> 00:29:18,130 So say I want to enable clock for Port f I would write this. 363 00:29:18,150 --> 00:29:26,260 This is what I want to in C language to enable clock access for Port f this bit here gives me this register 364 00:29:26,270 --> 00:29:27,690 that we've just created. 365 00:29:27,690 --> 00:29:30,660 So that is why I'm using the operator. 366 00:29:30,660 --> 00:29:35,000 So anyway you see the arrow if you just think way you see the underscore. 367 00:29:35,310 --> 00:29:38,000 If you had to convey this to C language it becomes an arrow. 368 00:29:38,640 --> 00:29:45,810 And for those of you who know you know basic data structures of C C in this you know that are C GC GPL 369 00:29:45,810 --> 00:29:52,200 you is a member of this CIS controls which is a structure like I explained earlier. 370 00:29:52,200 --> 00:29:52,990 Right. 371 00:29:53,040 --> 00:29:53,490 Moving on. 372 00:29:53,490 --> 00:29:55,940 So if you do understand any of what I just said. 373 00:29:55,970 --> 00:29:57,870 Just send me a message. 374 00:29:57,870 --> 00:30:00,960 So we have our RC GC GPL you register. 375 00:30:01,110 --> 00:30:10,880 We're going to do the same for GPL U A and it s registers so we can create GPL you a piece. 376 00:30:10,920 --> 00:30:16,400 I'm going to see the GPL you f sorry I keep saying eh. 377 00:30:16,830 --> 00:30:17,520 We have a way. 378 00:30:17,630 --> 00:30:26,440 Oh uh LDA switches on GPL you f do play F base but I ended up fetching GPL you a bass. 379 00:30:27,180 --> 00:30:29,020 This is ridiculous. 380 00:30:29,040 --> 00:30:36,000 Let's go and get GPL you f g p you f do we have it 381 00:30:47,690 --> 00:30:48,570 just bear with me. 382 00:30:56,820 --> 00:30:58,020 Um. 383 00:30:58,290 --> 00:31:05,860 I'm just gonna do d e end to get one registered D to um the digital will register. 384 00:31:05,890 --> 00:31:06,190 Okay. 385 00:31:06,220 --> 00:31:07,570 This is the key player U.S. 386 00:31:12,250 --> 00:31:12,910 Denholm 387 00:31:16,220 --> 00:31:17,600 register descriptions. 388 00:31:17,600 --> 00:31:19,390 Let's see what we have. 389 00:31:19,430 --> 00:31:19,850 Okay. 390 00:31:19,850 --> 00:31:24,500 So over here it gives us the complete addresses of the GPL you registers. 391 00:31:24,560 --> 00:31:28,070 Okay I'm on page number. 392 00:31:28,480 --> 00:31:29,120 Let's see. 393 00:31:29,120 --> 00:31:30,120 I'm on Page. 394 00:31:30,380 --> 00:31:32,750 Page Number Six hundred and sixty two. 395 00:31:33,320 --> 00:31:35,720 So um I'm looking for the GPL. 396 00:31:35,720 --> 00:31:42,200 You f register um the GPL you f register bass address and I'm using APB which is the default. 397 00:31:42,230 --> 00:31:43,510 I'm not using HP. 398 00:31:43,580 --> 00:31:44,900 What do I mean by default. 399 00:31:44,900 --> 00:31:47,180 I'm deciding which address to use. 400 00:31:47,180 --> 00:31:48,190 There's no default here. 401 00:31:48,230 --> 00:31:51,190 I'm using the APB right to copy this. 402 00:31:52,430 --> 00:31:52,780 Yeah. 403 00:31:53,030 --> 00:31:53,390 Um. 404 00:31:53,420 --> 00:31:53,670 Yeah. 405 00:31:53,720 --> 00:31:56,990 So GPL you f APB bass address. 406 00:31:56,990 --> 00:32:05,420 I'm gonna copy this then you can use this as I just cleaned a dot in there. 407 00:32:05,440 --> 00:32:11,500 Now we are going to look for the various GPA registers to do that. 408 00:32:11,500 --> 00:32:19,030 One thing we we can do is just to behave naive if I didn't know how to program this board the Texas 409 00:32:19,030 --> 00:32:19,820 Instrument. 410 00:32:20,180 --> 00:32:27,160 Um the guys at the guys at Texas Instruments and the ladies who wrote the um the reference my door in 411 00:32:27,160 --> 00:32:33,190 the data sheet they provide the steps steps for sort of working with the GPA. 412 00:32:33,220 --> 00:32:36,010 Let's see if given a step by step. 413 00:32:36,220 --> 00:32:37,250 Okay. 414 00:32:37,810 --> 00:32:41,410 This is it initialization and configuration. 415 00:32:41,480 --> 00:32:42,190 Who goes over here. 416 00:32:42,190 --> 00:32:48,340 Did you apply with more jokes maybe access to different memory just like we mentioned like uh previously 417 00:32:48,370 --> 00:32:54,710 the legacy a picture I.D. APB advanced peripheral but is backwards compatible with previous devices. 418 00:32:54,820 --> 00:33:00,930 The other aperture the advanced high performance bus HP offers the same register map but provides better 419 00:33:00,940 --> 00:33:03,670 back to back access before most than APB. 420 00:33:03,670 --> 00:33:09,100 These approaches are mutually exclusive meaning we can have just one. 421 00:33:09,190 --> 00:33:15,310 The aperture enabled for a given GPL your port is controlled by the appropriate port in the GPL you 422 00:33:15,430 --> 00:33:19,000 each keep playing HPC register. 423 00:33:19,480 --> 00:33:21,950 Okay. 424 00:33:22,010 --> 00:33:24,220 Note that GPL you can only access. 425 00:33:24,220 --> 00:33:29,520 Note that GPL you can only be accessed through the HB aperture. 426 00:33:29,530 --> 00:33:35,080 Note that the you play you can only be access to the HB aperture. 427 00:33:35,100 --> 00:33:37,130 This is strange. 428 00:33:37,400 --> 00:33:38,030 Mm hmm. 429 00:33:44,030 --> 00:33:45,980 Yeah yeah. 430 00:33:47,430 --> 00:33:47,970 Okay. 431 00:33:47,980 --> 00:33:53,890 You need not worry about this because I have tried this you can access it both through the HP and APB 432 00:33:53,910 --> 00:33:55,640 a picture. 433 00:33:56,140 --> 00:33:57,420 So I wonder why does it not. 434 00:33:57,460 --> 00:33:58,440 That's creepy. 435 00:33:58,450 --> 00:34:01,610 I can only be accessed through the HB. 436 00:34:01,870 --> 00:34:02,490 Okay. 437 00:34:02,570 --> 00:34:05,840 Anyway so these are the steps to figure out a GPL Europeans. 438 00:34:06,010 --> 00:34:12,880 We face enable clock access and then we set a direction using that direction register sets the direction 439 00:34:12,880 --> 00:34:18,040 of the GPL your port use in that direction register and to set a direction means to decide whether it 440 00:34:18,040 --> 00:34:23,740 should be input or output and then configure the alternate function select if we want to configure it 441 00:34:23,740 --> 00:34:31,580 will alternate function and then if we want it to drive something like a DC motor we can set the. 442 00:34:32,350 --> 00:34:34,780 We can get we can set to decry for strength. 443 00:34:34,780 --> 00:34:37,440 This basically means to set the current. 444 00:34:37,780 --> 00:34:45,370 We have to our for our eight hour and then after that we can set some pull up registers pull down registers 445 00:34:45,400 --> 00:34:52,390 or output drain program each part in the port to have it up pull up pull it out or open drain. 446 00:34:52,660 --> 00:34:53,530 Right. 447 00:34:53,800 --> 00:35:00,130 And then we can said this but when are we going to do decompose we start to do is to set a direction 448 00:35:00,130 --> 00:35:07,260 register and then to set the ditch to enable to digitally enable the pin. 449 00:35:07,300 --> 00:35:09,220 There should be a d e n register. 450 00:35:09,290 --> 00:35:15,990 Okay to digitally enabled a pin over here and then to read and write the data into the data register 451 00:35:16,030 --> 00:35:20,140 so you can read more about this if you want to get a complete picture. 452 00:35:20,640 --> 00:35:21,040 Right. 453 00:35:22,180 --> 00:35:29,970 So let's go find a direction register it should be found here. 454 00:35:30,980 --> 00:35:35,940 Cause we are in the GPL u um section okay. 455 00:35:35,950 --> 00:35:37,390 You give us a list of. 456 00:35:37,720 --> 00:35:37,950 Yeah. 457 00:35:37,960 --> 00:35:42,090 Give us a summary of the register and the various various offsets. 458 00:35:42,100 --> 00:35:44,890 But I want us to go to what it registers. 459 00:35:44,920 --> 00:35:45,300 Okay. 460 00:35:45,670 --> 00:35:46,570 Um. 461 00:35:46,600 --> 00:35:52,270 This that direction registered the GPL you direction register is that data direction register sets in 462 00:35:52,270 --> 00:35:53,690 a bit and a desire register. 463 00:35:53,690 --> 00:36:00,070 Can't forget that corresponded to be an output while clearing the pin meaning setting a bit I mean and 464 00:36:00,070 --> 00:36:04,130 setting it to zero config as their corresponding pin to be an input. 465 00:36:04,630 --> 00:36:13,480 So if we want to set a P F to as output we've got a right to want to bet number two in a way. 466 00:36:13,510 --> 00:36:13,920 Yeah. 467 00:36:13,960 --> 00:36:18,320 He has the offset of this register is 0 x for sure sure. 468 00:36:18,430 --> 00:36:21,380 Okay so I'm gonna create this register. 469 00:36:23,420 --> 00:36:27,060 I'll come here and see your GP. 470 00:36:27,070 --> 00:36:34,200 I f said GPL you f d I are for direction 471 00:36:36,830 --> 00:36:39,630 offset and you. 472 00:36:39,640 --> 00:36:47,490 Q You said this is your ex force your issue let's confirm that it's your ex force your issue right. 473 00:36:47,530 --> 00:36:56,800 So once we've done that we can create the other and we can create the register itself GPL you F D I 474 00:36:56,890 --> 00:37:07,980 R and R you are here for register and this is equal to the GPA f page address plus the GPL you f offset 475 00:37:14,420 --> 00:37:14,840 right. 476 00:37:15,260 --> 00:37:23,210 So the next register will deal with is the um the GPL you f data register so I'm gonna say since we 477 00:37:23,210 --> 00:37:24,300 have the offset. 478 00:37:24,350 --> 00:37:28,560 Since we have the base I simply need to drop the offset and create the register. 479 00:37:28,730 --> 00:37:34,910 I'm gonna write over here GPL you f data offset 480 00:37:37,800 --> 00:37:47,720 and then I'm gonna say a Q you we don't have it yet so I'll leave it blank and then GPL f data are mean 481 00:37:47,750 --> 00:37:49,290 in the register itself. 482 00:37:49,320 --> 00:37:52,310 This a course the GPL you f base 483 00:37:59,410 --> 00:38:01,810 plus t offset. 484 00:38:02,590 --> 00:38:03,030 Okay. 485 00:38:03,070 --> 00:38:08,110 Once this is done we need to sort out the key you output. 486 00:38:08,290 --> 00:38:16,070 Um the digital enabled register which is that the end source GPA f DG n offset. 487 00:38:16,750 --> 00:38:19,150 And then we say to you we fetch later. 488 00:38:19,210 --> 00:38:25,810 So GPL you f the N R over here the real register 489 00:38:28,660 --> 00:38:31,450 and we know this to be the base 490 00:38:34,460 --> 00:38:35,780 plus to offset 491 00:38:38,510 --> 00:38:39,060 right. 492 00:38:41,180 --> 00:38:45,290 So let's go locate the offset of these two registers. 493 00:38:45,410 --> 00:38:49,340 How many miles is this a bit. 494 00:38:49,340 --> 00:38:50,020 Right. 495 00:38:50,060 --> 00:38:53,880 So um let's find the um the offset of the data register. 496 00:38:54,350 --> 00:38:56,020 Gonna come back to the data sheet. 497 00:38:57,320 --> 00:38:59,330 So I've got to tell your data register. 498 00:38:59,330 --> 00:39:00,980 You can read about it from here. 499 00:39:01,040 --> 00:39:04,680 If you want the offset is sure X Sure. 500 00:39:04,890 --> 00:39:06,600 So good a place that over here 501 00:39:09,800 --> 00:39:10,670 rather strange 502 00:39:17,930 --> 00:39:21,350 to see the data register as a tricky one. 503 00:39:21,350 --> 00:39:24,980 This is not the offset data right. 504 00:39:24,980 --> 00:39:28,270 Yes that is it's different from other registers. 505 00:39:28,310 --> 00:39:29,960 We talk about that later. 506 00:39:30,440 --> 00:39:31,900 So I'm gonna keep that open. 507 00:39:31,910 --> 00:39:37,610 The GPL UDP and the digital mini will register the um. 508 00:39:37,750 --> 00:39:40,000 We scroll down here for the n 509 00:39:49,520 --> 00:39:50,990 it should be down here somewhere. 510 00:40:06,380 --> 00:40:08,440 Um research 511 00:40:13,290 --> 00:40:17,130 d e n here it is. 512 00:40:17,330 --> 00:40:21,190 So the offsets for this is your x5 one c. 513 00:40:22,040 --> 00:40:28,810 Okay. 514 00:40:29,650 --> 00:40:30,110 Right. 515 00:40:32,900 --> 00:40:33,330 Okay. 516 00:40:33,380 --> 00:40:35,680 So back to the data register. 517 00:40:36,170 --> 00:40:40,670 Um in the data sheet we saw the offset of the data register to be sure extra issue. 518 00:40:41,150 --> 00:40:44,790 Um but if we use your x years for it it wouldn't work. 519 00:40:44,810 --> 00:40:54,350 The actual offset is 0 x 3 FC and um the reason why this is I think uh would have to create a separate 520 00:40:54,350 --> 00:41:02,270 lesson to explain how the GPL your data register is configured or it arranged a bit different from the 521 00:41:02,270 --> 00:41:03,040 other registers. 522 00:41:03,080 --> 00:41:08,610 So for now this is still a way to accept this offsets for the GPL data register. 523 00:41:09,740 --> 00:41:12,140 Yeah I want you to accept this at face value. 524 00:41:12,200 --> 00:41:17,860 I'm going to add it up an article or if you do less and explain why this is the offset. 525 00:41:18,110 --> 00:41:18,520 Right. 526 00:41:18,530 --> 00:41:19,300 Moving on. 527 00:41:20,480 --> 00:41:29,210 So we um we saw that in the GPL you in the um in the RC GC GPL you register would need to set bits number 528 00:41:29,210 --> 00:41:33,250 5 to 1 in order to allow clock access for Port f. 529 00:41:33,770 --> 00:41:35,620 I'm gonna create a symbolic name for that. 530 00:41:35,630 --> 00:41:45,260 I'm gonna say GPL you f enable and enable I'm gonna see you can you and I'm gonna shift one two bits 531 00:41:45,270 --> 00:41:50,570 number five shift one to position number five and then I'm gonna create another symbolic name to turn 532 00:41:50,570 --> 00:41:51,660 on the red LCD. 533 00:41:53,630 --> 00:41:56,490 We already know what a red is connected to P.F. 1. 534 00:41:56,600 --> 00:42:04,700 So I'm gonna shift 1 to position number 1 shift 1 2 bits Number 1 like this and then I'm going to do 535 00:42:04,970 --> 00:42:09,340 for the green LCD LCD screen 536 00:42:14,020 --> 00:42:17,080 Oh which is which 537 00:42:20,080 --> 00:42:24,420 blue SPF two green SPF 3. 538 00:42:24,570 --> 00:42:29,100 I think this is blue and this is green. 539 00:42:29,120 --> 00:42:31,530 Right. 540 00:42:32,200 --> 00:42:33,570 So a lady blue 541 00:42:37,050 --> 00:42:37,680 Q You 542 00:42:41,070 --> 00:42:42,840 two and then a lady green. 543 00:42:47,300 --> 00:42:50,800 Q You were right. 544 00:42:50,870 --> 00:42:52,370 So we've got all of this. 545 00:42:53,720 --> 00:42:55,750 Um I'm going to clean our notes 546 00:42:59,490 --> 00:42:59,910 right. 547 00:43:00,210 --> 00:43:06,640 So we've been able to locate and create symbolic names for all the relevant registers we require. 548 00:43:07,230 --> 00:43:10,920 So let's continue in the next lesson and let's implement a. 549 00:43:10,950 --> 00:43:12,600 Driver in the next lesson I'll see you in the.