Day 38 mat385

• Announcements:
  • Exams returned:
    • Mean: 78%
    • SD: 9.5%
    • Exam 3
    • Exam 3 Key
    • You can make up points by coming to see me. You can get back 20% of your missed points by paying me a visit, so that we can talk about what you did wrong. View the key, first, however.
  • Reminder: Second Project Description (due May 1)

• Questions on things?

• Let's wrap up section 7.2: Logic Networks

• then start section 7.3: Minimization

Links:

• Why carry-lookahead out-performs simple full adders:

  "The 4-bit adder we just created is called a ripple-carry adder. It gets that name because the carry bits "ripple" from one adder to the next. This implementation has the advantage of simplicity but the disadvantage of speed problems. In a real circuit, gates take time to switch states (the time is on the order of nanoseconds, but in high-speed computers nanoseconds matter). So 32-bit or 64-bit ripple-carry adders might take 100 to 200 nanoseconds to settle into their final sum because of carry ripple. For this reason, engineers have created more advanced adders called carry-lookahead adders. The number of gates required to implement carry-lookahead is large, but the settling time for the adder is much better."

• How electromagnets work
• How relays work