WEBVTT 1 00:00:00.000 --> 00:00:04.240 All right, let's dive into microprocessors today. Cool you shared 2 00:00:04.240 --> 00:00:09.679 a chapter from Microprocessor two. Communication in a Digital System. 3 00:00:09.599 --> 00:00:12.720 By Philip Darsh Right by Philip darsh good choice. 4 00:00:13.039 --> 00:00:16.120 Yeah, it looks like he really gets into the wheeze 5 00:00:16.160 --> 00:00:19.440 on how all the parts of a digital system. 6 00:00:19.199 --> 00:00:19.839 Like your computer. 7 00:00:20.320 --> 00:00:23.079 Yeah, exactly, like your computer actually talk to each other. 8 00:00:23.239 --> 00:00:25.800 Yeah. It's way more complex than people think for sure. 9 00:00:25.839 --> 00:00:27.679 That's what we're going to unpack in this deep die. Right, 10 00:00:27.920 --> 00:00:31.280 the concept of the bus the boss, I'm already intrigued. 11 00:00:31.320 --> 00:00:32.960 Isn't it more than just a simple connection? 12 00:00:33.320 --> 00:00:34.280 Oh? Yeah, way more? 13 00:00:34.399 --> 00:00:34.719 Okay. 14 00:00:34.759 --> 00:00:38.359 The bus is like the central nervous system of a 15 00:00:38.399 --> 00:00:43.679 digital system. Okay, think of it as an information super highway, okay, 16 00:00:43.960 --> 00:00:49.320 with data constantly flowing between the microprocessor, the memory, and peripherals. 17 00:00:49.520 --> 00:00:53.159 I like that analogy. So data is the traffic on 18 00:00:53.159 --> 00:00:55.560 this highway. Yeah. Does that mean there can be traffic 19 00:00:55.640 --> 00:00:56.159 jams too? 20 00:00:56.600 --> 00:00:59.960 Absolutely, Just like a real highway. You have bottlenecks when 21 00:01:00.119 --> 00:01:02.679 multiple devices want to use the bus at the same time, 22 00:01:03.200 --> 00:01:05.959 and that's where bus arbitration comes in. It's like the 23 00:01:06.000 --> 00:01:10.079 traffic management system with rules to decide who gets priority. 24 00:01:10.239 --> 00:01:12.200 So it's not just a free for all. There's an 25 00:01:12.239 --> 00:01:15.799 actual logic, there's rule deciding which data gets to. 26 00:01:15.760 --> 00:01:18.519 Go first, right, And the chapter talks about different arbitration 27 00:01:18.680 --> 00:01:23.000 schemes you know, yeah, fixed priority where some devices always 28 00:01:23.040 --> 00:01:25.599 get to go first, round robin, which is like taking 29 00:01:25.640 --> 00:01:28.959 turns first come, first serve, which can be a little chaotic. 30 00:01:29.439 --> 00:01:34.920 So that's fascinating. And the chapter mentions different types of buses, right, yes, 31 00:01:35.200 --> 00:01:38.280 like control, address and data buses. 32 00:01:38.359 --> 00:01:38.879 That's right. 33 00:01:38.959 --> 00:01:40.120 What's the deal with that? 34 00:01:40.439 --> 00:01:44.840 So each bus carries a specific type of information, okay, 35 00:01:45.000 --> 00:01:48.159 and they all work together for seamless communication. 36 00:01:48.359 --> 00:01:48.680 Got it. 37 00:01:48.920 --> 00:01:52.599 Think of it as like a three lane highway. One 38 00:01:52.680 --> 00:01:55.760 lane for control signals. Imagine those are the traffic signals 39 00:01:55.760 --> 00:02:00.519 and signs, one lane dedicated to addresses, you know. Think 40 00:02:00.560 --> 00:02:04.120 of those as the GPS coordinates telling data where to go. 41 00:02:04.400 --> 00:02:07.439 And then the third lane reserved for the actual data 42 00:02:07.480 --> 00:02:08.240 being transferred. 43 00:02:08.280 --> 00:02:11.120 So it's like a perfectly coordinated system, it is. That's 44 00:02:11.120 --> 00:02:13.960 really cool. Yeah, what I'm curious about is this bus 45 00:02:14.000 --> 00:02:16.319 w thing. Okay, why does that matter? 46 00:02:16.479 --> 00:02:20.120 So think of the bus with as the number of 47 00:02:20.199 --> 00:02:22.919 lanes on our data highway. Oh yeah, a wider bus 48 00:02:22.960 --> 00:02:25.199 like a thirty two bit bus compared to an eight 49 00:02:25.319 --> 00:02:29.479 bit bus can carry more data simultaneously. It's like having 50 00:02:29.520 --> 00:02:32.479 a multi lane highway versus a single lane road. Right, 51 00:02:32.759 --> 00:02:35.800 the wider one can just handle a much higher volume 52 00:02:35.840 --> 00:02:36.319 of traffic. 53 00:02:36.400 --> 00:02:38.520 That makes sense. That's a great way to visualize it. Yeah, 54 00:02:38.599 --> 00:02:41.560 so wider bus, faster data transfer. 55 00:02:41.719 --> 00:02:43.400 Faster data transfer, got it. 56 00:02:43.439 --> 00:02:48.199 Now, what about this serial versus parallel communication. Yeah, I'm 57 00:02:48.240 --> 00:02:49.719 seeing both of those mentioned in the chapter. 58 00:02:49.800 --> 00:02:52.919 Okay, So imagine serial communication as a single lane road 59 00:02:53.599 --> 00:02:56.680 where bits of data travel one by one, knows to tail. 60 00:02:57.400 --> 00:03:01.879 It's simple, cost effective, but not the fact. Parallel communication, 61 00:03:01.960 --> 00:03:03.960 on the other hand, is like a multi lane highway 62 00:03:04.360 --> 00:03:08.039 where multiple bits can travel side by side dister, but 63 00:03:08.199 --> 00:03:09.800 requires more complex wiring. 64 00:03:09.919 --> 00:03:13.639 So cereals like the scenic route maybe for smaller data packets. Yeah, 65 00:03:13.800 --> 00:03:16.919 parallels the express lane for when you need speed exactly. 66 00:03:17.159 --> 00:03:20.240 And you know what, the IBMPC actually used a partially 67 00:03:20.319 --> 00:03:24.199 multiplex bus, the eighty eighty eight. Really, it combined elements 68 00:03:24.199 --> 00:03:27.479 of both cereal and parallel. It was a clever cost 69 00:03:27.479 --> 00:03:29.280 saving design choice back in the day. 70 00:03:29.439 --> 00:03:31.719 Oh that's really interesting. So even in the early days 71 00:03:31.719 --> 00:03:35.479 they were optimizing for cost and efficiency oh yeah. Now, 72 00:03:35.719 --> 00:03:38.639 something that's bit on my mind is timing. Okay, how 73 00:03:38.680 --> 00:03:41.680 do all these components stay in sync? The chapter talks 74 00:03:41.680 --> 00:03:45.199 about synchronous and asynchronous communication. What's the difference? 75 00:03:45.360 --> 00:03:49.319 So, synchronous communication is like a perfectly choreographed dance, okay, 76 00:03:49.360 --> 00:03:52.360 Everything happens in sync with a clock signal. Think of 77 00:03:52.400 --> 00:03:55.400 it as like the conductor's baton, keeping everyone on beat. 78 00:03:56.319 --> 00:04:00.560 It makes it reliable, but very dependent on precise time. Okay, 79 00:04:00.800 --> 00:04:02.680 any slight delay can throw things off. 80 00:04:03.039 --> 00:04:05.719 What about asynchronous communication, it's more like a. 81 00:04:05.680 --> 00:04:06.960 Free flowing conversation. 82 00:04:07.280 --> 00:04:07.599 Okay. 83 00:04:08.080 --> 00:04:12.199 Devices communicate without a shared clock signal, so it gives 84 00:04:12.199 --> 00:04:15.919 it more flexibility. But to avoid chaos, they rely on 85 00:04:16.079 --> 00:04:18.439 handshake protocols and shake protocols. 86 00:04:18.560 --> 00:04:19.720 Yes, that sounds interesting. 87 00:04:19.920 --> 00:04:23.120 Imagine sending a text and waiting for a reply to 88 00:04:23.199 --> 00:04:27.399 confirm the other person received it. Handshake protocols work similarly, 89 00:04:27.680 --> 00:04:31.560 but in the digital world they use request and acknowledge 90 00:04:31.600 --> 00:04:37.000 signals right, basically digital handshakes to ensure data is received correctly. 91 00:04:37.600 --> 00:04:40.800 So it's like building in a confirmation step to avoid 92 00:04:40.920 --> 00:04:44.759 messages getting lost exactly. That's smart. Yeah, are there different 93 00:04:44.800 --> 00:04:46.120 types of handshakes? There? 94 00:04:46.160 --> 00:04:48.879 Are you have two phase and four phase handshakes, each 95 00:04:48.959 --> 00:04:51.720 with its own You know, speed and efficiency trade offs. 96 00:04:51.800 --> 00:04:52.240 Got it. 97 00:04:52.240 --> 00:04:54.759 It's a bit like choosing between a quick nod of 98 00:04:54.800 --> 00:04:59.199 acknowledgment or a full blown handshake. The context determines what's 99 00:04:59.240 --> 00:04:59.839 more efficient. 100 00:05:00.079 --> 00:05:03.399 Okay, So we've got our data buses traffic management with 101 00:05:03.519 --> 00:05:08.160 arbitration handshakes to ensure smooth communication. How do we know 102 00:05:08.240 --> 00:05:10.800 that data itself isn't getting corrupted during all this back 103 00:05:10.839 --> 00:05:11.199 and forth? 104 00:05:11.240 --> 00:05:16.199 Excellent point. Data integrity is crucial, and the chapter describes 105 00:05:16.279 --> 00:05:21.199 techniques like bundled data and single rail encoding, simple but 106 00:05:21.399 --> 00:05:24.360 effective ways to validate the data being transmitted. 107 00:05:24.720 --> 00:05:27.560 Bundled data. Bundled data sounds straightforward, it is. 108 00:05:27.800 --> 00:05:30.759 Ok You basically send the data along with a signal 109 00:05:30.800 --> 00:05:34.120 that acts like a seal of approval, confirming its validity. 110 00:05:34.199 --> 00:05:36.720 It's like adding a tamperproof seal to a package. 111 00:05:36.959 --> 00:05:38.720 And single rail encoding. 112 00:05:38.879 --> 00:05:42.120 Single rail uses a single wire to represent both the 113 00:05:42.199 --> 00:05:46.439 data and its validity. It's simple, but has limitations in 114 00:05:46.519 --> 00:05:50.920 terms of speed and robustness. A more robust approach is 115 00:05:51.000 --> 00:05:55.120 dual rail encoding, also known as one of two code. Okay, 116 00:05:55.480 --> 00:05:59.240 This technique uses two wires for each bit, and only 117 00:05:59.319 --> 00:06:01.920 one wires bus to carry a signal at any time, 118 00:06:02.399 --> 00:06:04.519 so it makes it easier to detect if an error 119 00:06:04.519 --> 00:06:08.360 occurred oh during transmission. Interesting adding a layer of protection. 120 00:06:09.000 --> 00:06:12.040 So much thought goes into ensuring the data stays intact. 121 00:06:12.160 --> 00:06:14.800 Yeah, it's like they thought of everything they try to 122 00:06:15.040 --> 00:06:18.079 And we haven't even gotten to special bus cycles. Oh yeah, 123 00:06:18.120 --> 00:06:21.480 which handle more complex operations. All right, but maybe we 124 00:06:21.480 --> 00:06:22.759 should save that for part two. 125 00:06:23.279 --> 00:06:26.279 Agreed, Let's give our listeners a chance to process this 126 00:06:26.360 --> 00:06:30.000 information before we dive into even more fascinating aspects of 127 00:06:30.079 --> 00:06:31.560 microprocessor communication. 128 00:06:31.680 --> 00:06:32.439 That's a good idea. 129 00:06:32.879 --> 00:06:33.959 Stay tuned for part two. 130 00:06:34.079 --> 00:06:36.519 Absolutely, welcome back back for more. 131 00:06:37.000 --> 00:06:41.959 We left off with the promise of diving into these 132 00:06:42.519 --> 00:06:45.199 special bus cycles. What are they all about? 133 00:06:45.680 --> 00:06:48.879 So think of them as the advanced maneuvers on our 134 00:06:49.120 --> 00:06:53.319 data highway instead of just basic reads and writes. Special 135 00:06:53.319 --> 00:06:56.920 bus cycles handle more complex operations. Okay, like when you 136 00:06:57.040 --> 00:07:00.199 need to modify data that's already stored in memory. 137 00:07:00.199 --> 00:07:01.040 So give me an example. 138 00:07:01.160 --> 00:07:05.360 Take DRAM or dynamic random access memory. It's the main 139 00:07:05.399 --> 00:07:08.680 memory in most computers, but it requires a special type 140 00:07:08.680 --> 00:07:11.800 of bus cycle called read modify. Right, So you first 141 00:07:11.879 --> 00:07:15.079 have to read the existing data, modify it, and then 142 00:07:15.160 --> 00:07:17.959 write it back, all in one coordinated sequence. 143 00:07:18.000 --> 00:07:20.600 So it's not as simple as just overwriting the old data. 144 00:07:20.639 --> 00:07:23.560 Not with DRAM. It's a bit more involved, but essential 145 00:07:23.639 --> 00:07:26.560 for how most computer memory functions. And then you have 146 00:07:26.680 --> 00:07:30.439 scenarios where you need to communicate with multiple devices at once. Okay, 147 00:07:30.600 --> 00:07:32.800 that's where broadcast and broad call come in. 148 00:07:32.879 --> 00:07:35.680 Broadcasts and broad call, yeah, so it's like sending a 149 00:07:35.800 --> 00:07:38.600 mass email instead of individual messages exactly. 150 00:07:38.680 --> 00:07:42.759 Broadcast is like sending the same data to multiple devices simultaneously. 151 00:07:42.839 --> 00:07:43.160 Got it. 152 00:07:43.279 --> 00:07:45.600 Think of it as a system wide announcement. 153 00:07:45.839 --> 00:07:46.199 Okay. 154 00:07:46.399 --> 00:07:49.720 Broad call is the opposite. It's like collecting information from 155 00:07:49.759 --> 00:07:51.000 multiple devices at once. 156 00:07:51.639 --> 00:07:54.480 Makes sense. Are there any other special bus cycles mentioned 157 00:07:54.519 --> 00:07:55.040 in the chapter. 158 00:07:55.279 --> 00:07:56.920 Yes, there's burst mode. 159 00:07:57.120 --> 00:07:58.240 Burst mode which is. 160 00:07:58.279 --> 00:08:02.199 Used for efficiently transferring large chunks of data. Okay, think 161 00:08:02.240 --> 00:08:05.000 of it like downloading a large file instead of getting 162 00:08:05.040 --> 00:08:08.680 it piece by piece. Burst mode allows for a continuous 163 00:08:08.680 --> 00:08:12.160 stream of data, right, significantly speeding up the process. 164 00:08:12.519 --> 00:08:15.680 That's way more efficient, more efficient. So we've got these 165 00:08:15.720 --> 00:08:20.360 special bus cycles handling these complex scenarios. Yeah, but what 166 00:08:20.600 --> 00:08:26.000 happens when a device needs the microprocessors attention urgently, Okay, 167 00:08:26.160 --> 00:08:27.399 does it just have to wait its turn. 168 00:08:27.439 --> 00:08:28.720 That's where interrupts come in. 169 00:08:28.720 --> 00:08:29.199 Interruption. 170 00:08:29.360 --> 00:08:32.159 Yeah, they're like the emergency alert system of a digital system. 171 00:08:32.279 --> 00:08:32.600 Okay. 172 00:08:32.759 --> 00:08:36.039 Imagine you're cooking dinner and the smoke alarm goes off, Right, 173 00:08:36.159 --> 00:08:39.399 you immediately stop what you're doing and address the urgent situation. 174 00:08:39.639 --> 00:08:40.840 Of course, it's a priority. 175 00:08:40.879 --> 00:08:45.440 Exactly. Interrupts work similarly, there's signals that tell the processor 176 00:08:45.519 --> 00:08:48.759 to pause its current task and handle a high priority 177 00:08:48.759 --> 00:08:51.799 event like a keystroke or a mouse click or a 178 00:08:51.840 --> 00:08:52.720 critical error. 179 00:08:52.759 --> 00:08:54.720 So it's like pushing a button that says, hey, pay 180 00:08:54.720 --> 00:08:55.799 attention to me right now. 181 00:08:55.960 --> 00:08:57.480 Yeah, exactly, got it. 182 00:08:57.960 --> 00:09:01.679 And the chapter explains how in signs can be shared, yes, 183 00:09:02.240 --> 00:09:05.840 but that this needs careful management to avoid missing requests. 184 00:09:06.039 --> 00:09:09.840 Right. Imagine multiple people shouting for your attention at the 185 00:09:09.919 --> 00:09:12.799 same time. Right, It's easy to miss something important. 186 00:09:13.240 --> 00:09:15.639 That makes sense. You don't want those urgent messages getting 187 00:09:15.679 --> 00:09:18.360 lost in the chaos. Now, so far we focused on 188 00:09:18.399 --> 00:09:21.200 the bus itself, right, Can we zoom out and look 189 00:09:21.240 --> 00:09:23.919 at how all these different buses and components connect in 190 00:09:24.000 --> 00:09:25.360 a typical computer system. 191 00:09:25.440 --> 00:09:29.159 Absolutely, think of a computer as a city. Okay, with 192 00:09:29.279 --> 00:09:32.799 different districts connected by a network of roads. Right, you 193 00:09:32.840 --> 00:09:36.639 have the central business district that's like the microprocessor, the 194 00:09:36.720 --> 00:09:40.039 residential areas which are like the memory modules, and the 195 00:09:40.080 --> 00:09:42.200 industrial zones which are like the peripherals. 196 00:09:42.440 --> 00:09:44.240 Okay, I could see that analogy working. 197 00:09:44.360 --> 00:09:48.240 Yeah, And just like a city needs efficient transportation, a 198 00:09:48.279 --> 00:09:51.320 computer needs different types of buses to connect everything. 199 00:09:51.440 --> 00:09:51.600 Right. 200 00:09:51.720 --> 00:09:56.159 You have internal buses within the microprocessor itself, Okay, system 201 00:09:56.200 --> 00:09:59.919 buses connecting major components like the CPU and memory, and 202 00:10:00.120 --> 00:10:03.679 external buses for peripherals like hard drives and expansion cards. 203 00:10:03.679 --> 00:10:05.559 So it's like a hierarchy of buses, each with its 204 00:10:05.559 --> 00:10:07.000 own purpose exactly. 205 00:10:07.320 --> 00:10:10.960 And to manage the flow of data between different buses, 206 00:10:11.039 --> 00:10:15.200 ok you have bridges and chipsets. Bridges and chipsets, they 207 00:10:15.240 --> 00:10:20.039 act like traffic interchanges, routing data to the correct destination. 208 00:10:20.360 --> 00:10:23.399 So that's pretty amazing. It's a good, perfectly organized transportation system. 209 00:10:23.480 --> 00:10:24.720 But for data it is. 210 00:10:24.799 --> 00:10:27.440 And remember the pcibus we mentioned earlier. Yeah, it was 211 00:10:27.480 --> 00:10:31.480 a significant advancement because it was designed to be independent 212 00:10:31.559 --> 00:10:34.759 of the microprocessor, right, allowing for a wide range of 213 00:10:34.799 --> 00:10:38.559 expansion cards like graphics cards, sound cards, and network adapters. 214 00:10:38.720 --> 00:10:41.840 Right, all those different cards. Yeah, it's fascinating to think 215 00:10:41.879 --> 00:10:45.559 about how they all communicated seamlessly with the rest of 216 00:10:45.600 --> 00:10:46.080 the system. 217 00:10:46.279 --> 00:10:50.919 It is, and speaking of evolution. As microprocessors became more 218 00:10:51.039 --> 00:10:56.039 complex with multiple cores and specialized units, traditional buses started 219 00:10:56.080 --> 00:10:59.559 to show their limitations. Okay, it's like a city outgrowing 220 00:10:59.600 --> 00:11:01.039 its existing road network. 221 00:11:01.279 --> 00:11:01.600 Huh. 222 00:11:01.639 --> 00:11:05.200 You need a more advanced solution, and that's where network 223 00:11:05.240 --> 00:11:07.080 on chip or no C comes in. 224 00:11:07.559 --> 00:11:10.200 No C. You tease this earlier. Yes, it sounds like 225 00:11:10.240 --> 00:11:13.080 the next level of on chip communication. It is what 226 00:11:13.120 --> 00:11:13.960 makes it so special. 227 00:11:14.159 --> 00:11:17.639 So no C is a paradigm shift from the traditional 228 00:11:17.720 --> 00:11:21.519 shared bus architecture. Okay, imagine instead of having a few 229 00:11:21.559 --> 00:11:25.600 major highways connecting everything, you have a network of smaller, 230 00:11:25.840 --> 00:11:29.799 interconnected roads that can handle more traffic and are less 231 00:11:29.960 --> 00:11:31.080 prone to bottlenecks. 232 00:11:31.120 --> 00:11:33.399 So it's a more distributed approach exactly. 233 00:11:33.960 --> 00:11:37.600 New C uses a network of interconnected routers to move 234 00:11:37.679 --> 00:11:38.799 data around the chip. 235 00:11:39.000 --> 00:11:39.320 Okay. 236 00:11:39.480 --> 00:11:42.799 Each component or node has its own router okay, and 237 00:11:42.919 --> 00:11:46.320 data is transmitted in packets, much like on the Internet. 238 00:11:46.559 --> 00:11:50.279 So it's like having a mini Internet within the microprocessor itself. 239 00:11:50.360 --> 00:11:52.440 You got it, And just like the Internet, no C 240 00:11:52.639 --> 00:11:56.879 offers scalability. You can add more components without overwhelming the system. 241 00:11:57.279 --> 00:12:01.039 It also provides flexibility, allowing for different types of connections 242 00:12:01.080 --> 00:12:05.360 and data paths right to optimize for performance and power consumption. 243 00:12:05.600 --> 00:12:08.320 So it's not just about speed, it's about efficiency too. 244 00:12:08.240 --> 00:12:12.000 Absolutely, and because data is transmitted in packets, only the 245 00:12:12.120 --> 00:12:17.759 necessary components are activated, which reduces overall power usage. Right. 246 00:12:17.960 --> 00:12:22.080 No C also allows for fine grain control over voltage 247 00:12:22.120 --> 00:12:25.960 and frequency, okay, further enhancing energy efficiency. 248 00:12:26.320 --> 00:12:28.759 This is incredible, it's pretty cool. It seems like no 249 00:12:28.879 --> 00:12:30.840 C is the future of on chip communication. 250 00:12:30.960 --> 00:12:33.200 Then it's certainly a major trend. 251 00:12:33.360 --> 00:12:33.720 Okay. 252 00:12:33.879 --> 00:12:36.519 Of course, there are challenges in designing and implementing no 253 00:12:36.639 --> 00:12:40.600 SE's right, you know, routing algorithms, congestion management, and ensuring 254 00:12:40.679 --> 00:12:45.480 data integrity are complex issues, but the potential benefits are enormous, 255 00:12:45.720 --> 00:12:48.799 especially as we continue to pack more transistors onto ever 256 00:12:48.879 --> 00:12:49.639 smaller chips. 257 00:12:50.120 --> 00:12:53.080 It's amazing how engineers are constantly pushing the boundaries of 258 00:12:53.080 --> 00:12:55.720 what's possible. It is we've come a long way from 259 00:12:55.759 --> 00:12:59.919 those early simple buses to this intricate world of no ce's. 260 00:13:00.120 --> 00:13:00.879 Yeah, long way. 261 00:13:01.000 --> 00:13:03.960 It makes you wonder what's next for microprocessor communication. 262 00:13:04.320 --> 00:13:07.200 It's an exciting time to be following this field. Yeah, 263 00:13:07.200 --> 00:13:09.840 but before we get too far ahead of ourselves, let's 264 00:13:09.879 --> 00:13:12.320 take a moment to appreciate something often overlooked. 265 00:13:12.639 --> 00:13:15.000 Okay, the power bus. The power bus. 266 00:13:15.559 --> 00:13:19.279 It may not be involved in communication directly, but it's 267 00:13:19.320 --> 00:13:22.200 the lifeline that provides the energy for everything to run. 268 00:13:22.360 --> 00:13:25.399 The power bus the unsung hero of the digital world. Absolutely, 269 00:13:25.440 --> 00:13:26.879 Maliars tell me more so. 270 00:13:27.000 --> 00:13:31.039 The power bus is like the electrical grid of a city, Okay, 271 00:13:31.120 --> 00:13:34.720 but on a microscopic scale. It's a network of conductors, 272 00:13:35.000 --> 00:13:39.600 usually copper traces, are wires that distribute electricity to every 273 00:13:39.720 --> 00:13:43.720 component on a chip or motherboard. And unlike your home's 274 00:13:43.799 --> 00:13:49.480 electrical outlet, which provides a single voltage, modern microprocessors require multiple, 275 00:13:49.919 --> 00:13:54.879 precisely regulated voltages to meet the needs of different components. 276 00:13:55.080 --> 00:13:57.559 So it's not just about delivering power. It's about delivering 277 00:13:57.600 --> 00:14:00.159 the right kind of power to each part of the 278 00:14:00.200 --> 00:14:01.279 system exactly. 279 00:14:01.360 --> 00:14:03.919 Think of it like having different types of power adapters 280 00:14:04.480 --> 00:14:07.759 for your phone, laptop, and other devices. Each one needs 281 00:14:07.759 --> 00:14:11.799 a specific voltage and current to operate correctly. The power 282 00:14:11.799 --> 00:14:14.960 bus ensures each component receives the right amount of power 283 00:14:15.039 --> 00:14:19.200 at the right time, allowing for optimal performance, stability, and 284 00:14:19.360 --> 00:14:20.360 energy efficiency. 285 00:14:20.519 --> 00:14:22.679 It's like a delicate balancing act, then it is. 286 00:14:22.840 --> 00:14:26.679 Power management is crucial, especially as our digital systems become 287 00:14:26.759 --> 00:14:30.879 more powerful and complex. Too much power can damage components, 288 00:14:31.200 --> 00:14:33.679 too little can lead to instability and malfunctions. 289 00:14:34.080 --> 00:14:36.519 So the next time I use my computer or a smartphone, 290 00:14:36.519 --> 00:14:40.320 I'll be thinking about all these intricate processes happening behind 291 00:14:40.320 --> 00:14:44.000 the scenes. You should including the power bus diligently keeping 292 00:14:44.080 --> 00:14:44.759 everything running. 293 00:14:44.840 --> 00:14:49.240 Absolutely, it's a testament to the ingenuity of engineers who 294 00:14:49.279 --> 00:14:52.759 have mastered the art of delivering power on such a 295 00:14:52.799 --> 00:14:53.679 tiny scale. 296 00:14:53.759 --> 00:14:54.399 It really is. 297 00:14:54.440 --> 00:14:56.840 But we've covered a lot of ground today we have. 298 00:14:57.080 --> 00:14:58.720 Maybe it's time to take a break and let our 299 00:14:58.720 --> 00:15:00.480 listener digest all this information. 300 00:15:00.840 --> 00:15:03.879 Agreed, we'll be back with part three of our deep dive, 301 00:15:04.240 --> 00:15:07.759 where we'll explore the evolution of communication protocols and standards. 302 00:15:07.799 --> 00:15:09.240 Looking forward to it, Stay. 303 00:15:09.000 --> 00:15:14.279 Tuned, Welcome back to our microprocessor deep dive. We've explored buses, 304 00:15:14.399 --> 00:15:17.559 data transfer, all that, even touched on the future with 305 00:15:17.679 --> 00:15:20.360 network on chip right, But something I'm really curious about 306 00:15:20.480 --> 00:15:23.519 is how all this evolved over time. Oh yeah, you know, 307 00:15:23.559 --> 00:15:26.440 from the early days of microprocessors to now. 308 00:15:26.759 --> 00:15:28.279 It's a fascinating history. 309 00:15:28.399 --> 00:15:28.639 Yeah. 310 00:15:28.639 --> 00:15:31.679 You know, in the early days, things were much simpler. 311 00:15:32.200 --> 00:15:36.840 Microprocessors like the Intel eighty eighty, the Motorola sixty eight hundred, 312 00:15:37.559 --> 00:15:41.440 they had they had basic buses, you know, limited in 313 00:15:41.639 --> 00:15:43.120 speed and capabilities. 314 00:15:43.200 --> 00:15:45.440 So were they like the dial up modems of their time. 315 00:15:45.679 --> 00:15:49.000 Yeah, that's a good analogy. Back then, you know, those 316 00:15:49.039 --> 00:15:51.639 early buses were sufficient for the tax at hand, right, 317 00:15:51.840 --> 00:15:57.200 But as microprocessors, as they rapidly advanced, the demand for faster, 318 00:15:57.440 --> 00:16:02.000 more robust communication grew and that's when we started seeing 319 00:16:02.000 --> 00:16:03.559 dedicated bus standards emerged. 320 00:16:03.639 --> 00:16:05.840 Okay, so what were some of the early pioneers in 321 00:16:06.559 --> 00:16:07.279 bus standards. 322 00:16:07.320 --> 00:16:10.960 So one of the first widely adopted standard was the 323 00:16:11.000 --> 00:16:13.519 S one hundred bus S one hundred bus, which came 324 00:16:13.559 --> 00:16:16.679 out in the mid nineteen seventies. It was a it 325 00:16:16.720 --> 00:16:20.559 was a parallel bus with you guessed it, one hundred 326 00:16:20.600 --> 00:16:24.039 lines used in some of the first personal computers. Oh wow, 327 00:16:24.159 --> 00:16:28.039 And it was it was a revolutionary step towards modularity, 328 00:16:28.080 --> 00:16:33.039 allowing for you know, various peripherals expansion cards to be connected. 329 00:16:33.120 --> 00:16:34.919 So the S one hundred bus was like opening up 330 00:16:34.919 --> 00:16:37.519 a whole new world of possibilities for early PCs. 331 00:16:37.720 --> 00:16:41.919 Exactly. It was a huge leap forward. However, as as 332 00:16:42.000 --> 00:16:45.720 processor speeds increased, the S one hundred bus started showing 333 00:16:45.799 --> 00:16:51.399 its limitations. Issues like signal reflections and crosstalk. 334 00:16:50.879 --> 00:16:52.440 Emerged, and cross stock. 335 00:16:52.360 --> 00:16:56.279 Which are which are basically electrical interference that can corrupt data. 336 00:16:56.759 --> 00:16:59.080 Think of it as like trying to have a conversation 337 00:16:59.240 --> 00:17:02.440 in a noisy room. Sometimes a message gets lost. 338 00:17:02.559 --> 00:17:05.240 So they needed a more robust solution, yeah, to keep 339 00:17:05.319 --> 00:17:07.200 up with the increasing speed and complexity. 340 00:17:07.319 --> 00:17:10.279 Right, and that and that need led to the development 341 00:17:10.319 --> 00:17:15.839 of standards like ISA and later PCI PCI. These names 342 00:17:15.960 --> 00:17:18.319 might ring a bell, especially if you've ever tinkered with 343 00:17:18.359 --> 00:17:19.319 a desktop PC. 344 00:17:19.839 --> 00:17:22.279 Oh yeah, I remember those ISA slots for those long 345 00:17:22.359 --> 00:17:23.880 black connectors on the motherboard. 346 00:17:23.960 --> 00:17:27.039 That's the one ISA stands for Industry Standard Architecture. 347 00:17:27.319 --> 00:17:27.480 Right. 348 00:17:27.559 --> 00:17:31.039 It was introduced by IBM in the early nineteen eighties. Right, 349 00:17:31.119 --> 00:17:33.960 and it was. It was a parallel bus, okay, that 350 00:17:34.000 --> 00:17:38.160 offered better performance and compatibility compared to its predecessors. 351 00:17:38.240 --> 00:17:41.720 Right, But even ISA eventually hit its limits, of course, 352 00:17:41.759 --> 00:17:45.039 as processor speeds continued to soar. So what came after is. 353 00:17:45.720 --> 00:17:50.359 Enter PCI okay, or Peripheral component interconnect Okay. In the 354 00:17:50.400 --> 00:17:52.960 mid nineteen nineties, okay, and it was a it was 355 00:17:52.960 --> 00:17:57.119 a high speed parallel bus Okay, that blue ISA out 356 00:17:57.119 --> 00:18:00.240 of the water in terms of data transfer rates. Wows us. 357 00:18:00.480 --> 00:18:03.640 It introduced features like bus mastering and plug and play. 358 00:18:03.839 --> 00:18:06.039 Bus mastering, Yeah, plug and play those are game changes 359 00:18:06.079 --> 00:18:06.400 back there. 360 00:18:06.400 --> 00:18:09.440 They were huge. Yeah. Made adding and configuring devices much 361 00:18:09.440 --> 00:18:10.400 easier for users. 362 00:18:10.480 --> 00:18:13.200 Yeah. I remember the days of having to manually set 363 00:18:14.200 --> 00:18:17.559 jumpers can figure IRQs for every new device. 364 00:18:17.880 --> 00:18:20.759 It was a pain, It was a headache. Yeah. PCI 365 00:18:20.880 --> 00:18:27.440 simplified things significantly. Bus Mastering allowed peripherals to access memory 366 00:18:27.480 --> 00:18:31.519 directly without bogging down the CPU, and plug and play 367 00:18:31.720 --> 00:18:34.640 made installing new hardware practically effortless. 368 00:18:34.960 --> 00:18:35.160 Yeah. 369 00:18:35.400 --> 00:18:38.599 It truly was a revolution in PC architecture. 370 00:18:38.839 --> 00:18:42.119 So PCI was a major step forward. But as we've seen, 371 00:18:42.480 --> 00:18:46.119 technology never stand still. Now, what happened next in this 372 00:18:46.160 --> 00:18:47.599 evolution of bus standards? 373 00:18:47.759 --> 00:18:51.319 So as we entered the twenty first century, okay, a 374 00:18:51.359 --> 00:18:56.000 new trend emerged, the shift towards serial communication. Remember our 375 00:18:56.000 --> 00:18:59.359 earlier analogy of the single lane road versus the multi 376 00:18:59.400 --> 00:19:02.720 lane highway, right, parallel communicate like PCI was like that 377 00:19:02.839 --> 00:19:07.200 multi lane highway fast book complex. Serial communication, on the 378 00:19:07.200 --> 00:19:10.319 other hand, was like the single lane road, simpler, more 379 00:19:10.400 --> 00:19:11.240 cost effective. 380 00:19:11.519 --> 00:19:14.440 But didn't we say cereal was slower? How to become 381 00:19:14.480 --> 00:19:15.599 the dominant approach? 382 00:19:15.839 --> 00:19:20.319 That's the that's the key point. Advancements in technology allowed 383 00:19:20.319 --> 00:19:25.279 serial communication to reach speeds that rivaled okay, and eventually 384 00:19:25.319 --> 00:19:30.039 surpassed parallel buses and and this shift led to the 385 00:19:30.160 --> 00:19:35.240 rise of standards like PCI Express or PCI ECI. Success 386 00:19:35.240 --> 00:19:38.279 of the PCI exactly, PCI took the best of both worlds. 387 00:19:38.599 --> 00:19:41.799 It's a it's a high speed serial bus, right that 388 00:19:41.960 --> 00:19:45.960 uses point to point connections. Think of it as each 389 00:19:46.079 --> 00:19:51.000 device having a dedicated lane directly to the chipset or processor, 390 00:19:51.519 --> 00:19:54.039 eliminating the bottlenecks and contention of shared buses. 391 00:19:54.359 --> 00:19:56.559 So no more traffic jams on the data highway. 392 00:19:56.640 --> 00:19:57.880 No more traffic jams. 393 00:19:58.160 --> 00:20:01.599 Each device has its own express lane exactly. Wow. 394 00:20:01.759 --> 00:20:06.759 This architecture allows for incredible data transfer rates, and DCIE 395 00:20:06.920 --> 00:20:09.880 continues to evolve. We're now up to PCIe five point 396 00:20:09.960 --> 00:20:13.559 zero really, and even faster versions are on the horizon. 397 00:20:13.920 --> 00:20:16.160 It's mind boggling to think how far we've come from 398 00:20:16.160 --> 00:20:21.880 those early simple buses to these incredibly sophisticated serial communication standards. 399 00:20:21.920 --> 00:20:22.599 It really is. 400 00:20:22.720 --> 00:20:23.759 It's pretty amazing. 401 00:20:24.000 --> 00:20:30.240