21 February, 2000

The quiz

• Wednesday, 1 March
• Covers roughly Chapter 1 to Section 4.3 (don't cares)
• Closed book
• List of algebraic indentities will be provided
• Fill-in-the blank truth tables will be provided
• Fill-in-the blank Karnaugh maps will be provided
• Sources of problems
• Homework assignments
• Lab

• si = xi XOR yi XOR ci
• ci+1 = xi yi + ci(xi XOR yi)
• ci+1 = xi yi + ci xi+ ci yi
• Has significant propagation delay

• generate if both bits are 1
• gi = xi yi
• propagate if one bit is 1
• pi = xi + yi
• carry if
• ci+1 = gi + pi ci
• What the book suggests...
• pi = xi XOR yi
• Continuing the job
• ci+1 = gi + pi ci
• ci+2 = gi+1 + pi+1 gi + pi+1 pi ci
• ci+3 = gi+2 + pi+2 gi+1 + pi+2 pi+1 gi + pi+2 pi+1 pi ci
• ci+4 = gi+3 + pi+3 gi+2 + pi+3 pi+2 gi+1 + pi+3 pi+2 pi+1 gi + pi+3 pi+2 pi+1 pi ci
• and yet more
• ci+4 = g(i,i+3) + p(i,i+3) ci
• g(i,i+3) = gi+3 + pi+3 gi+2 + pi+3 pi+2 gi+1 + pi+3 pi+2 pi+1 gi
• p(i,i+3) = pi+3 pi+2 pi+1 pi

Or using the on-line notes of Shivkumar Kalyanarama of the Rensselaer Polytechnic Institute