Memory Module Select

Question

Problem: Memory Module Select. Solve this hands-on electronics task on EWskills.

Accepted Answer

From the behavioral table, Module Active = 1 only when both Address Match and Read Enable are 1.

So the required function is AND.

Let:

A = Address Match
B = Read Enable

AND gates are prohibited, so use the available OR and XOR gates.

X = A + B
Z = A XOR B

Now check the required output using X and Z:

A	B	X = A + B	Z = A XOR B	Y
0	0	0	0	0
0	1	1	1	0
1	0	1	1	0
1	1	1	0	1

From the table:

Y = X XOR Z

Substituting X and Z:

Y = (A + B) XOR (A XOR B)

Therefore:

Module Active =
(Address Match + Read Enable)
XOR
(Address Match XOR Read Enable)

Connect both inputs to an OR gate and an XOR gate, then XOR those two outputs to generate Module Active.

15. Memory Module Select