ECE 2020 Digital Design

Prof. Matthieu Bloch

Wednesday, October 22, 2025 (v1.0) - Number systems

Last time

  • Last time
    • positional number systems - conversion between systems
    • addition of unsigned integers
  • To be effectively prepared for today you should have:
    • Read your notes
  • No lab on Monday October 27, 2025
    • Need to cover more material
  • Homework 4 will be posted tonight
    • Coverage includes gates, logic, and number systems
  • Withdrawal date: Saturday October 25, 2025
    • We're working to give you Exam 2 grades before
    • Reach out to Academic Advisors in your units if you need guidance
  • Today
    • signed integers
    • combinational logic
  • Be ready!
    • Take your quizz at 10:15am

Unsigned integers and addition

Signed integers and addition/subtraction

  • Signed integer representation
    • signed magnitude
    • 1's complement
    • 2's complement
  • We will only focus on 2's complement for addition and subtraction

Combinational logic building blocks

  • A logic circuit is combinational if the output is completely determined by the current inputs
    • the output reacts (almost) immediately to a change of input
    • the circuit has no moemory
  • We will study several blocks
    • encoders and decoders
    • multiplexers and demultiplexers
    • adders
    • comparators

Until next time

  • To be effectively prepared for Monday October 27, 2025, you should:
    • Work on Homework 4