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Verify NAND operation

Wire up a 74LS00 chip on the breadboard and verify the NAND operation. You should draw a truth table indicating H or L values, as in Table 16 (A and B are inputs, and X is the output).

Don't forget to connect the power supply rails (V_CC and ground).

 

Table 16: NAND voltage table.

A	B	X
L	L
L	H
H	L
H	H

 

How do these voltages relate to logic values 0 (false) 1 (true)? Explain with the aid of Table 17.

 

Table 17: NAND logic table (positive logic - L=0, H=1).

A	B	X
0	0
0	1
1	0
1	1

 

What happens in mixed logic, where, for example, the inputs are positive logic and the output is negative, Table 18.

 

Table 18: NAND logic table (mixed logic case with positive logic inputs and negative logic outputs).

A	B	X
0	0
0	1
1	0
1	1

 

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