|
Computer Science 2500
Computer Organization
Rensselaer Polytechnic Institute
Spring 2009
|
|
Lecture 10: More Combinational Circuits: Adding Circuits
Date: Friday, February 20, 2009
- Announcements
- Office hours will end a bit early today: 2:45 PM
- Lab 4 due tonight.
- No new lab yet.
- Lecture assignment recap
- Adding Circuits
- Half adders
- Full adders
- Ripple-Carry adders
- Subtractors
- More efficient adders
- Sequential Circuits
Due at the start of class, Tuesday, February 24.
Turn in short answers to these questions. Please turn in a hard
copy (typeset or handwritten are OK). We will discuss these questions
during class, so no late submissions are accepted.
- Consider a 2-bit ripple-carry adder and a direct implementation
of a 2-bit adder using sum-of-products circuits (3 functions of 5
inputs). You need not construct the actual circuits, but discuss
the relative costs in terms of gate count and gate delay. How do
you think these change as the number of bits increases?