1. D IGITAL L OGIC By: Safwan Mawlood Digital Principles and Logic Design, A.Saha &N.Manna K ARNAUGH M APS (K MAPS )

2. D ON ’ T C ARE In certain digital systems, some input combinations never occur during the process of a normal operation because those input conditions are guaranteed never to occur. Such input combinations are called Don’t- Care Combinations. The function output may be either 1 or 0 and these functions are called incompletely specifies functions. These input combinations can be plotted on the Karnaugh map for further simplification of the function. The don’tcare combinations are represented by d or x or F.

3. D ON ’ T CARE TERM X X1 XX XX AB CD 00011110 00 01 11 10 AD

4. X11X X1 1 1 AB CD 00011110 00 01 11 10

5. E XERCISE 00X0 11X1 1100 0X00 AB CD 00011110 00 01 11 10 C’D