A truth table shows how the outputs of a digital circuit is dependent upon its inputs. It can be seen as the model theoretic meaning of the circuit. Logicians also make use of truth tables.
Consider a half adder which adds bits A and B giving the sum S and carry C.
The truth table below shows each of the four different combinations of the inputs A and B and
the S and C outputs for each combination.
A | B | S | C |
|---|---|---|---|
0 | 0 | 0 | 0 |
0 | 1 | 1 | 0 |
1 | 0 | 1 | 0 |
1 | 1 | 0 | 1 |
Mano, M. Morris, and Kime, Charles R. Logic and Computer Design Fundamentals. 2nd Edition. Prentice Hall, 2000.
Kleitz, W. Digital Microprocessor Fundamentals. 3rd Edition. Prentice Hall, 2000.
Copyright © 2014 Barry Watson. All rights reserved.