2022-12-09

[public] 138K views, 38.1K likes, dislikes audio only

Sebastian Lague

Displaying numbers is trickier than I expected! In this video we explore how to visualize the data inside of our simulated 4-bit registers, with the help of the double dabble algorithm and some seven segment displays.

Series playlist: https://www.youtube.com/playlist?list=PLFt_AvWsXl0dPhqVsKt1Ni_46ARyiCGSq

Simulation tool (work in progress): https://sebastian.itch.io/digital-logic-sim

Source code: https://github.com/SebLague/Digital-Logic-Sim

Support the channel: https://www.patreon.com/SebastianLague

Correction for a mistake in my boolean algebra explanation: /youtube/video/A-vLRThfJ4Q

Resources and Inspiration:

https://en.wikipedia.org/wiki/Double_dabble

https://electronics.stackexchange.com/questions/499884/3-digit-of-7-segment-on-logisim/499916#499916

https://pdf1.alldatasheet.com/datasheet-pdf/view/5697/MOTOROLA/SN54/74LS248.html

Music:

https://github.com/SebLague/Misc-Project-Info/blob/main/Digital-Logic-Sim/7Seg%20Music%20Credits.txt

Chapters

0:00 Intro

0:49 Two’s Complement Refresher

1:34 Seven-Segment Display + Truth Table

2:58 Boolean Algebra Basics

5:43 Simplifying the Equation

6:48 Converting Algebra to Logic Gates

8:33 Computer-Assisted Design

11:25 Testing the Digit Display Design

12:36 A Real-World Version (the 74LS248)

14:20 Visualizing the Data in a 4-bit Register

15:14 All Ten Digits

17:22 Binary Coded Decimal

19:49 The Double Dabble Algorithm

22:58 Dabbling with Logic Gates

24:05 Implementing Double Dabble

26:39 Displaying an 8-bit Number

27:18 Ripple Blanking

29:32 Displaying Negative Numbers

32:34 Testing the Final Design

33:50 Outro