Implementation of logic and digital systems
Schematic symbols for logic circuits

Given that the logical operations can be implemented using different technologies are generated logic diagrams. In logic circuit diagrams schematic symbols are used. Figure 3.5 Circuit symbol to represent logical sum, which has two inputs (left) and one output. Figure 3.6 is the schematic symbol for the logical product, which has two inputs and one output. Wheel in Figure 3.7 indicates negation. The diagrams are not drawn separately, but always in input or output tag for the product or sum.

Fig. 3.5, 3.6, 3.7: Addition, product, negation

Note: In some, particularly older schemes may be signs of another shape, not a square or a rectangle. Mark for negation is the same.

## Example 3.1

Draw the logic diagram of the circuit, which is expressed by the relation:

solution

SOLUTION
Fig. 3.8: Example 3.1

## Example 3.2

Draw the logic diagram of the circuit, which is expressed by the relation:

solution

SOLUTION
Fig. 3.9: Example 3.2