1 00:00:00,700 --> 00:00:01,920 Hello, welcome back. 2 00:00:02,320 --> 00:00:10,270 And this lesson, we going to see how to work with task notifications, what I'm going to do is make 3 00:00:10,270 --> 00:00:12,580 a copy of our drivers project. 4 00:00:12,580 --> 00:00:15,760 Some drivers, this one here, I'll make a copy of it. 5 00:00:16,390 --> 00:00:19,630 I'll say copy over here and paste over here. 6 00:00:21,840 --> 00:00:27,270 And this becomes 31 who call this task notifications. 7 00:00:32,420 --> 00:00:33,080 Like this. 8 00:00:35,680 --> 00:00:37,390 OK, I'm going to expand. 9 00:00:41,780 --> 00:00:46,830 Open the main door, see, fall over here, OK, this is what we have. 10 00:00:46,850 --> 00:00:51,500 This is our driver's fuda, our some driver's projects over here. 11 00:00:51,510 --> 00:00:55,520 We're going to use our external interrupts driver that we created yesterday. 12 00:00:55,850 --> 00:01:02,390 And what that is, is basically set in our PC 13 as an input interrupt such that when we press the PC 13 00:01:02,390 --> 00:01:10,040 13, we uninterrupted is generated and we can, you know, implement or run a piece of code in the interrupt 14 00:01:10,040 --> 00:01:10,980 request handler. 15 00:01:11,620 --> 00:01:14,920 OK, so this project, we don't need this. 16 00:01:14,950 --> 00:01:16,630 I'm going to clean this bit from it. 17 00:01:17,450 --> 00:01:19,970 So a project currently has no ARTUS. 18 00:01:21,590 --> 00:01:24,230 We don't need this as well, so I'll clean this. 19 00:01:24,350 --> 00:01:32,990 All we have is our inclusions and then we've initialized our UTX. 20 00:01:33,740 --> 00:01:41,130 OK, so to use notifications we need to enable notifications in our Simms's. 21 00:01:43,040 --> 00:01:45,050 The CMC is always the each file over here. 22 00:01:45,050 --> 00:01:49,940 Right click go to open declarations and you come down here. 23 00:01:50,360 --> 00:01:50,890 Over here. 24 00:01:50,900 --> 00:01:54,110 Currently we have just Tosk dot h included. 25 00:01:55,130 --> 00:01:56,360 Um not here. 26 00:01:56,360 --> 00:01:57,110 Sorry about that. 27 00:01:57,110 --> 00:01:57,740 Goodness. 28 00:01:57,740 --> 00:01:58,880 I'm losing my mind. 29 00:02:00,700 --> 00:02:07,160 We have to include notification by going to our free ARTUS configured HFA. 30 00:02:07,450 --> 00:02:09,960 Sorry, um, look at that. 31 00:02:09,970 --> 00:02:13,120 I was on a roll just talking about something else. 32 00:02:13,600 --> 00:02:16,410 OK, this fall here, free artist configurator. 33 00:02:16,810 --> 00:02:20,290 So just like we included the other artist component. 34 00:02:21,210 --> 00:02:31,470 We can search for notification or do control over here and such notification, it's not here, so I'm 35 00:02:31,470 --> 00:02:32,590 going to include it. 36 00:02:33,690 --> 00:02:36,750 So what we want to do is type. 37 00:02:39,440 --> 00:02:45,950 Define config task notifications, and then we said this to one, this will allow us to be able to use 38 00:02:45,950 --> 00:02:49,610 notifications controls to save come back to me not see. 39 00:02:51,020 --> 00:02:53,070 OK, we're going to have one task. 40 00:02:53,120 --> 00:02:54,500 This is the handler task. 41 00:02:54,710 --> 00:02:58,800 And then we're going to have our interrupted request handler. 42 00:02:59,720 --> 00:03:01,070 So what are we going to do? 43 00:03:01,190 --> 00:03:05,690 Is we going to initialize PC 13 for interruptive? 44 00:03:05,690 --> 00:03:09,290 So I copy this function and then I'll come over here. 45 00:03:11,400 --> 00:03:20,820 And then I call this function here, so P.S. 13 is enabled in its interrupt mode, and because it's 46 00:03:20,820 --> 00:03:26,190 interrupt, we've got to define the interrupt request handler or the interrupted service routine. 47 00:03:26,670 --> 00:03:36,030 The interrupt request handler for P.S. 13 is called XDA 15 dash 10 I.Q. It has to be written like this. 48 00:03:36,030 --> 00:03:38,000 This is its name in the vector table. 49 00:03:38,220 --> 00:03:46,320 And the reason it's a 15 dash 10 is because interrupts request external interrupts 10 through 15. 50 00:03:46,320 --> 00:03:47,640 Share the same interrupt. 51 00:03:47,970 --> 00:03:49,020 Request a line. 52 00:03:49,050 --> 00:03:52,610 That is why we're doing an extra 10 dash 15 over here. 53 00:03:52,770 --> 00:04:00,150 If we had if we were using less European such as 10, 11, 12, 13, then in here we would have an if 54 00:04:00,150 --> 00:04:07,350 close or we'd be using it to check whether the interrupt is from 10, 11, 12, 13, 14 or 15. 55 00:04:07,650 --> 00:04:13,590 But because we have just one, which is from 13, we need not check the source of it. 56 00:04:14,010 --> 00:04:14,520 In a way. 57 00:04:14,730 --> 00:04:18,380 Like I said, this is bare metal stuff, so I wouldn't go deeper into this. 58 00:04:18,690 --> 00:04:26,670 So what we have so far with initialize our P.S. 13 as an input interrupts and then we have the empty 59 00:04:26,670 --> 00:04:28,290 interrupt request handler here. 60 00:04:28,860 --> 00:04:34,890 OK, we going to create a task, a single task known as the handler task. 61 00:04:34,890 --> 00:04:39,180 And we can give it any priority because it is the only task in our system. 62 00:04:39,670 --> 00:04:44,730 So currently the name of this task function is going to be on the task. 63 00:04:45,000 --> 00:04:53,130 The task is called handler task and we given it a stack size of 128, which is equal to five one two 64 00:04:53,130 --> 00:04:53,550 bytes. 65 00:04:54,300 --> 00:05:00,210 OK, so this stack size volume is what we have here and we're given a priority of three. 66 00:05:00,210 --> 00:05:05,880 You can give a priority of whatever you want because it's the only task here and we're going to store 67 00:05:05,880 --> 00:05:07,680 the handle of this task. 68 00:05:09,610 --> 00:05:14,380 In a variable here, so we have this variable Hondo task. 69 00:05:16,650 --> 00:05:22,410 So once the task is created, the handle of the task will be stored in this variable here. 70 00:05:22,620 --> 00:05:24,240 OK, looking good so far. 71 00:05:25,260 --> 00:05:33,510 Next, we going to start our scheduler using our V task search that starts function once that is done. 72 00:05:33,540 --> 00:05:40,420 We going to come over here and implement the task function of our handler task. 73 00:05:41,010 --> 00:05:44,010 So we say, well, one in here. 74 00:05:46,690 --> 00:05:48,790 Open and close, OK? 75 00:05:49,270 --> 00:05:56,670 And over here, we're going to define a delay amount, you're going to define a hundred times delay. 76 00:05:56,890 --> 00:06:03,670 So I'm going to say Purdum's to takes one hundred and I'm going to store the value in this variable 77 00:06:03,670 --> 00:06:05,920 known as X marks expected block time. 78 00:06:06,980 --> 00:06:14,690 OK, so this is our interrupt request handler, when we press our push button, whatever we please in 79 00:06:14,690 --> 00:06:17,990 this function is going to be executed. 80 00:06:18,740 --> 00:06:24,590 OK, what we want to do is whenever the push button is pressed, we want to send a notification to our 81 00:06:24,590 --> 00:06:25,880 handler task over here. 82 00:06:27,380 --> 00:06:35,750 OK, so I'm going to start by defining X higher priority task to be walking or define this variable 83 00:06:35,760 --> 00:06:37,480 and we can set it to false. 84 00:06:38,210 --> 00:06:40,040 We don't have any higher priority tasks. 85 00:06:40,040 --> 00:06:41,060 We want to wake up. 86 00:06:41,060 --> 00:06:47,480 We have a single task and I'll leave it up to you to run these experiments with multiple tasks and CD 87 00:06:47,510 --> 00:06:55,250 effect of setting higher priority task, walking to true or false in a mortarboard or in a multi task 88 00:06:56,270 --> 00:06:58,370 system with different priorities. 89 00:07:00,450 --> 00:07:09,810 OK, so then what we do is what we want to happen here, we want to send a notification to our to ask, 90 00:07:10,110 --> 00:07:16,280 so we use the V task, notify give from Isar function to send a notification. 91 00:07:16,830 --> 00:07:20,910 So this function takes the task. 92 00:07:21,780 --> 00:07:26,550 The task you want to send a notification to takes the handle of that task as the first argument. 93 00:07:26,760 --> 00:07:29,790 And a second argument is the higher priority task. 94 00:07:29,790 --> 00:07:30,210 Wolken. 95 00:07:31,770 --> 00:07:38,370 And once that is done for our interruptive, we need to clear the interruptive flag right to recommit. 96 00:07:38,880 --> 00:07:44,110 So to clear the flag, we simply write this hexadecimal value in the P r register. 97 00:07:44,640 --> 00:07:45,120 Okay. 98 00:07:45,990 --> 00:07:49,280 Once that's done, we're going to request a context switch. 99 00:07:49,770 --> 00:07:53,150 So the interrupt request handler will tell the process. 100 00:07:53,220 --> 00:08:00,390 Okay, I'm done during the process or so we use the port from ESADE, just like we saw in our other 101 00:08:00,390 --> 00:08:03,900 examples where we have where we are entraps request handles. 102 00:08:04,140 --> 00:08:09,960 So party from ESR and then we pass X higher priority task walking us arguments here. 103 00:08:11,470 --> 00:08:13,080 So this will send a notification. 104 00:08:13,920 --> 00:08:14,450 OK. 105 00:08:17,030 --> 00:08:23,780 So once that is done, we would go to our handler to ask to see if a notification. 106 00:08:25,180 --> 00:08:35,920 Was received in our handler task over here, come and call the take notification function and dysfunction 107 00:08:35,920 --> 00:08:36,330 here. 108 00:08:37,870 --> 00:08:38,790 Come over here. 109 00:08:38,950 --> 00:08:44,200 We see this the name of the function you task, notify, take. 110 00:08:48,900 --> 00:08:57,330 This function takes two arguments, the first argument here is the is the Xolair count on exit. 111 00:08:58,750 --> 00:09:02,980 As you can see over here, it's called a clear count on exit and of course, the next argument is that 112 00:09:02,980 --> 00:09:03,520 block time. 113 00:09:03,700 --> 00:09:06,590 So this one here, clear count on exit. 114 00:09:06,670 --> 00:09:15,340 If we set it to false, then these are the Arktos notification value is decrements it before we exit 115 00:09:15,340 --> 00:09:16,050 this function. 116 00:09:16,420 --> 00:09:17,620 So you can think of this. 117 00:09:17,620 --> 00:09:24,010 This is like account in semaphore being decrements it whenever we take the SEMAFO, if we said is to 118 00:09:24,010 --> 00:09:30,910 force thus the effect we have if we said is to true, it's like a binary semaphore being set to zero 119 00:09:31,210 --> 00:09:34,150 because a binary semaphore can either be one or zero. 120 00:09:34,990 --> 00:09:37,480 OK, so over here we settled into force. 121 00:09:37,760 --> 00:09:38,200 OK. 122 00:09:40,030 --> 00:09:40,440 Right. 123 00:09:41,940 --> 00:09:48,510 So we're going to see if this is not equal to zero, then we want to see want to print something essentially. 124 00:09:50,340 --> 00:09:58,350 When I come over here and print this, we see handler task in event, meaning we've received it. 125 00:09:58,470 --> 00:10:05,520 Essentially what we use this for is to be able if this handler task had an important piece of information, 126 00:10:05,880 --> 00:10:11,150 then it would notify it that it's done its job and then we process further. 127 00:10:11,280 --> 00:10:20,050 Yeah, over here we can see do something and do something we are doing is basically printing this to 128 00:10:20,050 --> 00:10:20,750 the US. 129 00:10:21,840 --> 00:10:29,340 OK, so once this is done, we can have an LST condition here if we want. 130 00:10:34,760 --> 00:10:35,830 Do something as well. 131 00:10:40,350 --> 00:10:49,320 OK, so that is it, we can take our task prototype to the top over here. 132 00:10:51,660 --> 00:10:52,200 And then. 133 00:10:54,360 --> 00:10:57,150 We build and see what we have a click over here to build. 134 00:11:01,220 --> 00:11:02,690 It's built successfully. 135 00:11:05,550 --> 00:11:07,020 All right, click over here. 136 00:11:08,990 --> 00:11:09,590 And then. 137 00:11:11,430 --> 00:11:18,300 Go to debark us ystem thirty two, thirty one, and then OK over here. 138 00:11:22,200 --> 00:11:23,880 And then click the switch over here. 139 00:11:26,880 --> 00:11:28,270 I'll clear what we have here. 140 00:11:28,380 --> 00:11:30,340 We don't need this, actually, so I'll leave it. 141 00:11:31,080 --> 00:11:32,430 I'll bring real time. 142 00:11:35,400 --> 00:11:41,790 I'm going to select this new line mode port over here, I'm going to select the portrait, then I'm 143 00:11:41,790 --> 00:11:43,230 going to select the port. 144 00:11:45,740 --> 00:11:50,360 And then I'm going to open it, then I'm going to minimize this. 145 00:11:55,430 --> 00:12:00,040 And I'm going to click to play over here, OK? 146 00:12:00,110 --> 00:12:03,110 Awkward is running, so I'm going to press the push button. 147 00:12:04,040 --> 00:12:06,070 And as you can see, I press the push button. 148 00:12:06,080 --> 00:12:08,070 It says, let us process an event. 149 00:12:08,300 --> 00:12:11,830 So when I press the interrupt, a case of press again. 150 00:12:12,680 --> 00:12:20,660 I've pressed again, so basically and notification is sent to our handler to ask whenever the push button 151 00:12:20,660 --> 00:12:27,380 is pressed, when a push button is pressed in our interrupts request handler, we say notify the handler 152 00:12:27,380 --> 00:12:27,800 task. 153 00:12:28,850 --> 00:12:34,310 OK, and over here, we just using the push button as an example, this could be you configuring your 154 00:12:34,310 --> 00:12:42,110 ADC to work in interrupt mode such that when there is a new piece of analog data, you can just notify 155 00:12:42,350 --> 00:12:49,700 a function that has your digital signal processing algorithm to process that new piece of data. 156 00:12:49,970 --> 00:12:56,720 Over here, we are using simple examples to explain these complex, powerful features that we have in 157 00:12:56,720 --> 00:12:57,500 the ARTUS. 158 00:12:58,190 --> 00:13:01,340 So this order is for this lesson, and I'll see you later. 159 00:13:01,350 --> 00:13:01,930 Have a nice day.