for class on Thursday March 2, 2000
Please read Chapter 4 sections 4.4.3, 4.4.4, 4.5, and 4.6 (pp. 152-165) and be prepared to discuss the following:
The text builds a 1-bit adder that has three inputs (two addends and carry-in) and two outputs (sum and carry-out). See if you can you come up with a simpler circuit that adds just two bits together, producing a sum and carry-out. Can you use two of these circuits (called half-adders in the trade), to make a full 1-bit adder (three inputs, two outputs)? Do you need an extra gate or two, on top of the two half-adders? Again, use gates with more than two inputs if you like.