The Central Processing Unit (CPU): Crash Course Computer Science #7

Take the 2017 PBS Digital Studios Survey: http://surveymonkey.com/r/pbsds2017. Today we’re going to build the ticking heart of every computer – the Central Processing Unit or CPU. The CPU’s job is to execute the programs we know and love – you know like GTA V, Slack… and Power Point. To make our CPU we’ll bring in our ALU and RAM we made in the previous two episodes and then with the help of Carrie Anne’s wonderful dictation (slowly) step through some clock cycles. WARNING: this is probably the most complicated episode in this series, we watched this a few times over ourselves, but don’t worry at about .03Hz we think you can keep up.

Produced in collaboration with PBS Digital Studios: http://youtube.com/pbsdigitalstudios

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50 Comments

  1. Ayejax on April 21, 2020 at 11:58 am

    When does register c and d get involved?

  2. Aydon Joseph on April 21, 2020 at 11:58 am

    I am very confused. How does the cpu tell the different instructions (binary instructions) apart? Is there a few logic gates that specifies which instructions it is and connects to the different components ? Please answer

  3. Angry Potato on April 21, 2020 at 11:58 am

    Friend : how CPU works?
    Me : you wouldn’t get it

  4. Savino Rojas on April 21, 2020 at 11:59 am

    So is one cycle fetch, decode, AND execute? Or is just one of those a cycle?

  5. Ayejax on April 21, 2020 at 12:01 pm

    @2:21 I get confused with the difference between instruction address register and instruction register

  6. Foxy and Toby MC on April 21, 2020 at 12:05 pm

    1:00 Ohh something new! 1: 01 Duhh

  7. Aee Bee Cee on April 21, 2020 at 12:07 pm

    Fetch code is to get code from where as said as instruction address register to instruction register
    Decode is recognize what to do and execute it

  8. Foxy and Toby MC on April 21, 2020 at 12:08 pm

    8:01 Execute? What did the dog/computer ever do to deserve to die?

  9. ISSARA SATYANAM on April 21, 2020 at 12:08 pm

    I was just staring at the creeper the whole time

  10. Foxy and Toby MC on April 21, 2020 at 12:08 pm

    8:00 Dog or Computer?

  11. muhammed ashif on April 21, 2020 at 12:09 pm

    Good explanation…

  12. sagar kolte on April 21, 2020 at 12:10 pm

    😫😫😫😫😫😫😫😫😫😫😫😫

  13. Mashca on April 21, 2020 at 12:11 pm

    don’t you speak of my beloved copy of half-life 2

  14. Chinmaya Chowdary on April 21, 2020 at 12:13 pm

    Excellent

  15. Jared Weiss on April 21, 2020 at 12:14 pm

    1:27 "this high level view is called the microarchitecture" haha this stuff is mindblowing

  16. FirePhoenixGamers on April 21, 2020 at 12:15 pm

    This video is fantastic

  17. Prachi Nainawa on April 21, 2020 at 12:15 pm

    Well explained, every country should follow this approach to teach.

  18. Alessio Grancini on April 21, 2020 at 12:16 pm

    is there any book/e-book related to this series ? amazing work !

  19. hard-core coder on April 21, 2020 at 12:16 pm

    Finally next episode is software. The reason I came to watch this series was that 😊

  20. Jeffrey Suen on April 21, 2020 at 12:16 pm

    This makes me appreciate when my computer is taking its time loading up a webpage. I see the wires tirelessly turning on and off according to a stream of signal to rush to the conclusion I see on my screen and the billions of bits Chrome uses on my ram. You go little puppy!

  21. Aee Bee Cee on April 21, 2020 at 12:17 pm

    So the control unit that mainly do fetch code, decode(recognize code) and sending execution code.

  22. Denise Portes-Kerr on April 21, 2020 at 12:19 pm

    This episode was hard

  23. Humza Vlogs on April 21, 2020 at 12:19 pm

    The two sides have played a total of 199 times. Pakistan have won 86 matches compared to India’s 70 victories. In Test matches and ODIs Pakistan has won more matches than India, although India has won six of the eight T20 International between the two sides.

  24. Ayejax on April 21, 2020 at 12:20 pm

    At @6:08 I have no idea how we got 01 is register b and 00 is register a lost me there and I’m not sure how you are counting in decimal I need a refresh on that

  25. psychopath on April 21, 2020 at 12:21 pm

    thank u so much

  26. Bunny Bro on April 21, 2020 at 12:27 pm

    Carrie Anne: there isn’t a mini Carrie Anne in every computer
    Me:(stares at the Carrie Anne talking to me on a 3×3cm window on my screen) well, what’re you doing there?!

  27. hard-core coder on April 21, 2020 at 12:27 pm

    Finally next episode is software. The reason I came to watch this series was that 😊

  28. majd suliman on April 21, 2020 at 12:28 pm

    help !.. I think I overclocked my brain with this video …. gobbeldygookooogluglu !

  29. Foxy and Toby MC on April 21, 2020 at 12:29 pm

    correction
    8:02

  30. Alireza Nouriani on April 21, 2020 at 12:32 pm

    Thanks to Carrie Anne. And everyone.

  31. Aee Bee Cee on April 21, 2020 at 12:32 pm

    Decode is input, execute is output.

  32. Foxy and Toby MC on April 21, 2020 at 12:32 pm

    @Ahron Maslin *Force closed*

  33. Khatija Bibi on April 21, 2020 at 12:32 pm

    When CPU crash in minute ..

  34. Brandon Laplace on April 21, 2020 at 12:33 pm

    You say computers are not magic when you say the multiplexer is has a 4 bit code to fetch memory what is happening physically to make that happen apparently computers are magic

  35. Mrzl_ on April 21, 2020 at 12:36 pm

    This woman is awesome. Computer science has never been so easy to understand!

  36. B Olubunmi on April 21, 2020 at 12:36 pm

    Why my brain not working lol

  37. Alireza Nouriani on April 21, 2020 at 12:38 pm

    Please put a mini Carrie Anne inside every CPU! 🙂

  38. Peter Pehlivan on April 21, 2020 at 12:39 pm

    ~ A N E W L E V E L O F A B S T R A C T I O N ~

  39. Никита Коляда on April 21, 2020 at 12:41 pm

    когда тебе нужно еще с английского на русский переводить настолько же быстро как и комп

  40. ahmed aliyu on April 21, 2020 at 12:41 pm

    Her brilliance is as intimidating as her charm. I love this class.

  41. Manas Sharma on April 21, 2020 at 12:42 pm

    Can anyone suggest some book or other learning material(offline or online) related to above and beginner friendly?

  42. M H on April 21, 2020 at 12:43 pm

    This is the kind of instruction I’ve been searching for with a lot of graphics!

  43. Ank Gupta on April 21, 2020 at 12:47 pm

    Great Series for any computer science enthusiast. The lady is so clear in concepts and explaining stuff. The series is for all the age groups. Thanks for such a smooth explanation.

  44. EPIC GAMER 420 on April 21, 2020 at 12:47 pm

    I have to watch this for homework anyone else?

  45. omom om on April 21, 2020 at 12:49 pm

    علي الطرباش أنو شرحك بفهم

  46. Lemonade on April 21, 2020 at 12:50 pm

    I bet the animator is a computer wiz after doing the graphics for this course. I’ve made technical animations before too, and I learned a lot about the topic I was animating.

  47. Mr Ocean on April 21, 2020 at 12:52 pm

    for students of this subject, this video is vague and lacks precision especially on what concerns registers they didn’t notice the Program counter register wich is the root of the instruction fetching
    As hard and complex this video seems to be it’s nothing you still cant passe an MIT test concerning this subject even if you learn this video by heart.

  48. Lemonade on April 21, 2020 at 12:52 pm

    So RAM is like the pantry or fridge, and registers is like the kitchen where you manipulate the ingredients. Interesting!

  49. Marcus Ihme on April 21, 2020 at 12:53 pm

    Fantastic job!

  50. Magic Man on April 21, 2020 at 12:56 pm

    Truly a firehose of information but it’s beautifully put together bravo. I never had the money for a CS degree, learned all of this out of books and remember absorbing each of these layers.

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