How the Clock Tells the CPU to "Move Forward"

[@CoreDumpped]

To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/CoreDumped. You’ll also get 20% off an annual premium subscription.

[@crystal4372]

Nice video, i have some questions: Does your work revolve around hardware or are you just learning this yourself and making youtube videos after self-study? How did you learn to animate these videos and what software do you use?

[@AcuteChronic]

Hate the embedded ads.

[@c0g3nt29]

It’s videos like these that make me appreciate the sheer wizardry behind the screen. Sitting here, comfortably abstracted from layers of intense engineering, I can't help but marvel at how decades of solving complex, tedious problems lets me blissfully ignore them-typing away on a machine that just works, as if by magic.

[@10hi01]

that pfp is crazy

[@johnpaulpascua3569]

If you go 1000 years back to the past with your smartphone, people will literally worship you. That's how advanced our tech today that we take for granted. 😂

[@princeakhil208]

I like ur profile intel is indeed dead inside

[@chakibchemso]

​@@johnpaulpascua3569 Or might get you killed for sorcery

[@refindoazhar1507]

​@@johnpaulpascua3569too far, even just 100 years ago most people would likely worship you.

[@juniuwu]

That emergent behaviour of chained flip-flops forming a binary counter is amazing. It almost feels like it just came out of nowhere.

[@CoreDumpped]

Fun fact: I was also stunned when I learned about it.

[@amj864]

@@CoreDumpped Is RDTSC implemented this way?

[@ArneChristianRosenfeldt]

It does not come out of nowhere. A circuit without memory acts like a function. A flip-flop has this feedback loop to know about the past. The combined state is two dimensional. I imagine hands running around the clock. Now if the clock frequency (edge steepness) and the memory decay live on vast different time scales, this clock gets squeezed into a line and the circuit stops counting. In a way this is only a slight expansion of a phase shifter.

[@adambickford8720]

@@ArneChristianRosenfeldt I think his point was we didn't decide to build a binary counter, it's just kind of the unexpected result of this aggregation of flip-flops. It obviously wasn't a coincidence for the designer and much iteration arrived at this elegant solution.

[@ArneChristianRosenfeldt]

@ ah, so yeah a frequency divider is a counter. Just accept that you cannot read out the counting value due to skew. It works great to trigger the drawing of sprites in the Vic-Ii in the C64.

[@bodycowlin]

2 videos in 1 month!? Today's not Halloween it's Christmas!! 🎄

[@monkyyy0]

-maria carry

Well, the octal to decimal joke was pretty smooth... Nice one man!

[@premsagar4438]

Yes, exactly... Exactly. This is what I was talking about bro. Cover everything! Make all those difficult-looking concepts easy!

[@khachikhatsagortsyan7027]

I'm simple human - I Immediately click the like button when I see Core Dumped uploaded a new video about CPUs

[@maheshkanojiya4858]

We are same bro

[@heavyhauldude9914]

Same here too!

[@-yttrium-1187]

Brilliant video. Though in real CPU's you wouldn't want to fetch, decode, execute and increment one cycle at a time since your fetch and decode would be idle 50% of your clock cycle. So I guess in a few video's from now we'll be talking about speculative execution and cache invalidation.

[@CoreDumpped]

Yes, you are right

[@Akronymus_]

simple pipelining that stalls on data dependencies would probably be a better intermediary step IMO

[@noahwilhelm3205]

Yeah it's an interesting mix of a pipelined CPU but also not executing the stages in parallel, most likely do to simplicity 🤫. Without out of order execution your only pipeline data hazard is a raw, which can easily be forwarded or stalled, so it wouldn't be too complex.

[@Akronymus_]

@@noahwilhelm3205 conditional jumps, indirect addressing and such would definitely need stalling as well. Easiest to just stall on certain kinds of instructions, that COULD have data dependencies. Altough, probably still quite a bit out for @CoreDumpped to bother with any time soon. First the individual stages have to be covered.

[@Akronymus_]

@@noahwilhelm3205 Dang my reply got removed. There are still hazards of data races with indirect memory accesses. But main memory in general is quite challenging with the fairly large delays. Altough, I guess you could run the RAM at cpu latency/throughput/frequency for explaining and introduce stuff like caching and such later.

[@pedrovelazquez138]

When I was 16, I remember using T-type flip flops to build a counter. I used a push button to increment. It reached 25 and then it restarted again, all of that with combinational circuits. I was very excited about this. I still remember working on a small table next to my bed. I was happy for the results, it worked.

[@tratmir]

Wow, this made so much sense! It also blew my mind how the binary flip-flops formed a counter.

[@skilz8098]

Yeah, it almost seems counter intuitive but chaining them together like that to create a binary counter is also very close to the idea of having a binary voltage divider.

[@markhaus]

Can’t wait for your process scheduler video. That’s one area I’ve always stumbled with.

[@givememoJo]

these are the kind of videos i pause when i am doing something besides like work or playing games because it would be to big of a loss missing even the slightest bit of information. thank you so much for your videos!

[@plrc4593]

O, another video soon after I subscribed you :D I must say you're one of the most valuable KZbinr I have seen :D You helped me to understand better how computers work. You helped me to understand the difference between heap and stack. I look forward to learning a lot of from you in the future.

[@MarianoBustos-i1f]

Dude, the insane amounts of work you put in the script, animation... everything...

[@FT91-z5j]

I love your videos there are amazing to watch. Little note at 13:11 the Push button should be switch betwen a logic One and a logic zero because your input pin is now is floating. You coud mention that any pin not connected to a proper input is a zero. I understand that it's much easier to understand the function of button for normal people but i believe the peopel that interested in that kind of stuff it is crucial to understand that a Output signal of any logic is not comparable to a button switch because you need a way to ensure the level will go to high or zero after you released the button. Maybe you could explain this in a one of your next videos so you can reference to it in your comming videos. Thanks for your amazing videos.

[@CoreDumpped]

You're right. Also, in real life, push-buttons are very unreliable in this kind of situations because there's a lot of bouncing in the metal-contacts, so when you push them they actually produce a lot of "edges".

[@ArneChristianRosenfeldt]

@@CoreDumppedthe first radio transmitters used these buttons. I think that EMI should only happen on making a contact. There is a short lightning. Lightning strikes in the sky create long wave radio.

[@adambickford8720]

These videos are for the freshman level learner. Let them enjoy their ideal diodes for a couple years.

[@omgiheartpie]

You are a treasure man. Can’t wait to just binge watch all your videos again over the winter break

[@metaname11]

Fantastic video! Your teaching style makes complex concepts so much easier to grasp. Keep up the great work! It’s clear you put a lot of effort into making this content informative and enjoyable. Keep up the amazing work-I can’t wait to see what you share next!

[@skilz8098]

That was probably one of the simplest ways to explain how binary or ring counters work based on a clock input signal and how they rely on both the gated latch - JK or T flip flops which also heavily rely on edge detectors. I've already known this from my own research and independent projects where most of my learned knowledge came from others such as Ben Eater, NAND to Tetris, and a few others. If only this kind of content was around 10-15 years ago when I started down this journey. Great stuff, great vids, keep up the great work!

[@wesleymesquita8380]

This kind of work should be presented in the very first introductory classes of computer science / engineering programs. This would tell the students: this is the reason you must take your basic eletronics class serious. Some schools handles courses in completely orthogonal paths and no real real and practical connection is made till graduate courses. Thank you for the high quality material!

[@ombrezz7030]

These videos are awesome, you don't find a lot of content on this website covering digital electronics at this quality.

[@desyfer1709]

Love your videos. Instant click. And they always answer some questions I always had....stuff like how exactly the OS interacts with hardware, or the role of BIOS, and some others including the stuff already in your videos!

[@inriinriinriinriinri]

You explained 3 months of my Comp Systems Architectures classes in 15 minutes. That's just incredible.

[@leshommesdupilly]

Square wave: Wait… It’s all sines ??? Fourier: Always has been… **gunshot**

[@skilz8098]

It's only all sines when I cosine for it. Sine here on the dotted lines.

[@mubafaw]

Clear crisp explanation. Many Thanks 😊👍

[@premsagar4438]

You can do everything Such as data structure visualisation and other aspects of the computer science too. One step at a time bro. Keep going!

[@Revoker1221]

Absolutely fantastic content. For the more advanced viewers, I also recommend watching "minimal 64x4 inside out" by Slu4. Where this video demonstrates the basic theory of how one goes about the instruction pipeline sequentially, the x64x4 video demonstrates how microcode (particularly control signals) can have mutiple stages of the pipeline executing simultaneously. It would also be nice to see microcode explained on this channel too, but it might take a while to get there haha.

[@deezydoezeet]

You're the G.O.A.T Chief George! This has actually been a subject of my curiosity for a while now. This is amazing stuff!

[@trimpta]

Clicked on this video in a heartbeat as soon as i saw it

[@sg9257]

Thanks for helping me understang things that i didnt know

[@ralfm.metzing8407]

Thanks a lot for these perfect illustrations!

[@harikirankante883]

This is exactly what was missing and been searching for this for many days🤓

[@jonathanprivitera9394]

I'm loving every upload so much, liked the video while the ads are still rolling and I know I won't remove the like. Keep up the good work!

[@vastabyss6496]

Okay I gotta admit, the title is fantastic, and so is the thumbail and content as always! Great video

[@vastabyss6496]

No it was changed 😭 The original title was something along the lines of "The Clock - The Heartbeat of the CPU"

[@stinchjack]

0:46 555 clocks are limited to abut 1KHz. The tolerances abut resistors on caps are also frustrating for exact timings. Also on a 5V circuit the 'high' part of the clock is limited to 3V.

[@pepinzachary]

i just can't believe how fucking beautiful computer science is oh my god. it's just magic

[@Polishpython]

instant click

[@MivelKhansa]

Same

[@hard.nurtai4209]

faster than a cpu

[@Cluni-80s]

Make a full course on this, assymbly, programming...etc and I will be the first to sign up. Amazing educational quality.

[@omaralikhan4633]

amazing as always, waiting for threads video

[@dxtechcreations]

thanks. I've got a lot of things learned again from your channel.

[@alejandroalzatesanchez]

2:30 Abusing parasitic capacitance is such a ballsy move. That's actually cool. _"It's not a bug it's a feature"_ at it's finest.

[@anthonybustamante5736]

How do you animate your videos!!! I have been absolutely binging your great work. Keep it up, it's awesome!

[@googigoog]

Brilliant content & animation!

[@CanThinkCanDo]

Man this is the answer I never got in engineering ❤❤❤❤ Amazing explanation mate

[@oronshifman]

Man!!! Love you're videos!

[@alejandroalzatesanchez]

This video feels like the fever dreams that I get trying to wrap around my mind the concepts. Pretty cool

[@Griffin12536]

Brilliant needs a dark mode version of their ad.

[@CashFlowTV554]

So when a CPU is advertised as 1GHz, does that mean it executes all 4 steps 1 billion times per second, or 250 million times per second? In other words is it the speed of the clock, or how many times per second it can actually Execute the decoded instruction?

[@momensy2136]

Bro, please keep up this good content. I can't play my role to keep this amazing work free, but one day, I will. Thx alot ❤

[@MD_Areeb]

I always watch his video 2 times to understand the concept more clearly

[@EyadAhmed-s7z]

I have been looking for this!

[@KhaledKimboo4]

You may be wondering why not just increase the clock speed to get unlimited cpu speed since your cpu is relatively as fast as it's clock, but going faster causes the signal to radiates (becomes radio waves) and never reach its destination , again (at least not as strong as needed to be ) you say so just reduce the distance a signal needs to travel inside cpu so we can use higher frequencies, and that's why we need smaller and smaller transistors

[@tthanhvu8891]

The first thing I ever do when watching Core Dumped’s new video is like the video.

[@ВладФоменко-р4е]

Best. Channel. Period.

[@anilshemade6048]

I wish these videos were made in my college days...❤❤❤

[@farhanrejwan]

if only our digital logic design course professor taught us flip-flops like this 8 years ago from now...

[@simplifyitofficial]

I Used To Like Your Videos Soooooo Much. I still Like Your Videos. KEEP IT UP. I was going to make that in real life. After buying lots of stuff, I realized that it would be impossible to make it using jumper wires and breadboards. But I still watch your videos to understand the concepts

[@JoydeepNath-b4j]

Can you please create a playlist on computer core fundamentals. Maintaining the sequence right from binary

[@stachowi]

This channel is next level

[@dzuchun]

electrodynamics isn't real, it can't hurt you also computers:

[@alexkfridges]

Beautiful video. Really really excellent

[@paca3107]

ideal timming. I just wondering how clock works because recently I am interested in building Chip8 interpreter. Maybe Vm/interpretters its a good topic for the next video?

[@AK-vx4dy]

You must be stopped. Your explanations are so good that soon we have epidemic of cpu designers / assembly programmers 😅

[@FranzSarmiento17]

Another Cored Dumped Video let's gooo

[@ShinSpiegel]

Amazing video, thanks for sharing.

[@mahmoudbasha4838]

I hope you make a video about boot process in detail under the hood plz

[@Mrh8913]

4:58 Minecraft redstoners need to take these lessons to become a true redstoner

[@CybernetonPL]

12:15 should I point out it counts up in binary and resets to zero after 1111?

[@diamonddemon7612]

tysm! time to finish my CPU!

[@taffareldelimaoliveira]

lets go back to circuit simulator and try to build one myself. Thanks so munc for this. Clear as water

[@mzaidibrahime]

Wow man. Top top presentation

[@tarlkudrick1174]

Does pressing a key on a keyboard do something similar to the manual clock advance button? That is, do keyboards work because pressing a key either interrupts an electric flow, or allows one to happen? I'd love a video from you (assuming you don't have one and I can't find it) about the lowest level interface that lets software control hardware, and hardware control software. I'm not sure if I'm asking for a video about how drivers work (at the lowest possible level), but maybe I am. I think I don't know enough about digital engineering to ask my question using the right terms, so I hope you can figure out what I'm asking for. Thanks! (New subscriber.)

[@CoreDumpped]

My video on Kernel Mode vs User Mode might answer your questions.

[@adambickford8720]

Yes, but its not 1:1 w/switches to keys. There's a reason most keyboards can only register a small number of simultaneous key presses (multiplexing).

[@arindamdas7341]

Great content...thanks 👍

[@joelasa5420]

Very good video. Please how does this enable the computer to execute multiples instructions at the same time in the pipeline? Since the stages of the pipeline are not activated simultanously by the clock? Another question. How do the cpu executes millions instructions per cycle of clock? Are there millions of pipeline stages?

[@akashr2283]

great job sir

[@norbytwister]

me encanta tu canal y he aprendido muchicimo, pero hay algo que no entiendo, quien le da la señal al reloj para activarse y hacer la secuencia completa?, desde ya muchisimas gracias, sos un genio

[@whermanntx]

When watching one video makes you go to the channel and find more. 🎉

[@dj10schannel]

Great vid 👍

[@kihwanlee5617]

Beautiful!

[@hard.nurtai4209]

ohhh yes. exactly what i was looking for

[@shis10]

Amazing video

[@leonarrator265]

ty mr. George

[@Beginning497]

🫡🫡mad respect from your student bro...

[@elzabethtatcher9570]

"Until next time, I'm Jorge" Next time, who knows...

[@adambickford8720]

Videos like this are why i tolerate the internet

[@ductainguyentran6821]

hope you can publish new video everry week !!!

[@mohamedelfmed3811]

How do you make the video animation. Which tool are used?

[@MACMAN2003]

the scariest part of halloween: computer science!!!!!

[@stinchjack]

13:03 Push buttons require debouncing

[@xyt098]

bro what software did you use to make animation or presentation like this?

[@farhanfaraan1]

So brilliant sir

[@oglothenerd]

MMU video when?

[@ArneChristianRosenfeldt]

Yeah, how does a MMU not introduce a lot of latency. Neither PS1 or Saturn used MMU. I think N64 had it, but it was optional. Also only used a small die area. No big TLB .

[@oglothenerd]

@@ArneChristianRosenfeldt The MMU is very crucial to modern operating systems.

[@ArneChristianRosenfeldt]

@ Android does not seem to like swapping. Also DRAM is cheap. So it is about memory protection?

[@oglothenerd]

@@ArneChristianRosenfeldt Yes. The MMU is the reason applications segfault instead of corrupting the memory of other processes, and the MMU is what maps virtual memory addresses for every process.

[@ArneChristianRosenfeldt]

@ virtual memory is a weird concept. So on a 32 bit system every process gets 4 GB address space. Then malloc leaves tons of space behind it to allow realloc. Imagine List in C# or Java . Once you get close to the page size, reserve like 256 pages capacity. So your program will probably never need to realloc a large growing list. All blobs are spread with empty pages in between to detect buffer overruns. A physical implementation could store a physical address in SI and DI. When code reads out these registers, they could be translated back to virtual memory. Same with the address registers on the 68k ISA. For low latency memory access.

[@BiplobHossainSorker]

Thanks

[@РайанКупер-э4о]

I'm thinking how a processor can be MA without the clock. In a biological system there is nothing similar to that clock. Organisms can detect rhythmic signals from outside, like rising and setting sun, but there is no inner clock that dictates synchronous work of everything. That creates interesting advantages. For example, one light sensitive cell in your eye can create signal no more frequent than 20-21 times a second. You may think this means that our eyes have 20 fraims per second, like your average TV. But this is false conclusion. In practice trained fighter pilots can identify plane modification even if it appears only for one 200s of a second. So how is that possible? The photosensitive cells are not synchronized. Each fires it's signal right when it gets hit by a photon, without waiting for any clock pulse, then it «cools down» for one 20s of a second and it's ready for the next photon. So this way continuously gathering signals from the whole retina the brain is able update the image faster than a light sensitive cell can update it's state. So with that in mind, can we make a system, that would allow us to use same effects?

[@CarlBach-ol9zb]

Actually, yes. You might still require a clock, though, for various reasons. But modern CPUs may perform the Fetch-Decode-Execute cycle concurrently and in parallel. I.e. The CPU may fetch the next instruction, while decoding a prior instruction, while executing an instruction that came before it. This speeds up data processing.

[@РайанКупер-э4о]

@CarlBach-ol9zb , not exactly what I was talking about, but it's cool too.

[@ArneChristianRosenfeldt]

Asynchronous logic was tried. Heck, DRAM was async up to the AtariJaguar. Then the Sega 32x switch to synchronous RAM. DEC Alpha and Pentium4 overdid it with the clock and wasted a lot power on just cycling. With 5 GHz cruise and 10 GHz clock possible in silicon, you don’t get much finer time grains. IO is slow in comparison. Camera sensors are read out in serial fashion. Maybe you invent a 3d chip.

[@huycuong6403]

Hi , could you explain quantum computer work? Thank

[@가사나다]

Then what happens if each stage fails or not done before one tick goes?

[@CoreDumpped]

Here we are assuming no fails and 1 instruction per cicle. Unfortunately, the implementation of circuitry needed to handle the situations you describe far too complex to explain in a single video.

[@MrOnlineCoder]

Great video, but I can't figure out - is your voice just so clear and badass, or it's AI voiced?

[@mlucianoeze]

I activated Set and Reset at the same time and the latch took a screenshot

[@rondamon4408]

Wow, If good clocks are important for speeding, I'd say that the fastest computer would be a Rolex

[@638electro]

Did I missed something or is CPU able to execute each instruction strictly in one clock tick?

[@johnpraveen7538]

Hi sir can you explain instructions set architecture please

[@hasaanmaalak-fr5ek]

Can you explane about file register in windows