Peter Lau
Bill Chun Wai Hung
Lab 13 Report – S3 Logic Gate
A. Describe the Set-up
The Circuit
setup is shown in figure 1.
Figure 1
B1. Describe Inputs
Stimuli:
DC 5V
4
Inverters: 7404
4 Nand
Gates: 7400
Table 1
a b c | S3
0 0 0 | 1
0 0 1 | 0
0 1 0 | 1
0 1 1 | 1
1 0 0 | 0
1 0 1 | 1
1 1 0 | 1
1 1 1 | 1
S3 = b + a'c' + ac
C. Describe What
you Observe
The LED
lit up when the S3 value indicated in Table 1 is 1, and the LED is off when the
S3 value indicated in Table 1 is 0.
D. What you can deduce
The
Boolean formula from the lecture was right, and the table 1 logic is right for
the circuit shown in figure 1.
The
logic works according to table 1.
Q1) If
you had only 3 nand gates, how
would you have connected the LED and the resistor to S3 in order to obtain the
same result?
This
questions is completely ignored.