Digital Systems: Principles and Design

8

Digital Systems

EXERCISES

1. Using the circuit in Figure 1.1, fill the Table 1.5 given below: [Assume negative

logic circuit and write logic state 1 when V < 0.8 V and 0 when V > 2.8 V to supply

voltage. Write * when indeterminate.]

TABLE 1.7

;,1 ,0

Y0 = 1

Y1 = 1

Y2 = 1

Y3 = 1

TABLE 1.6

SL SU Lamp Logic state of the Lamp

ON ON ON 1

OFF OFF OFF 0

ON OFF ON 1

OFF ON ON 1

TABLE 1.5

8

,

Logic state at ,8

,

Logic state at ,

5 V 1 V

4 V 0.75 V

3.5 V 0.5 V

2 V ~0 V

2. Redraw the circuit in Figure 1.2 so that outputs are as per Table1.6 below:

3. Consider the circuit in Figure 1.3. What will the states at D0, D1 when the input

Y2 = 1?

4. Using a pencil draw in a row horizontally ...