Sketch Your Circuits on These Pages Using the Provided Symbols

Homework 08 Due Monday 3/23/09

Sketch your circuits on these pages using the provided symbols. 1. Problem 5.19(a). U1 1 15 2 A Y0 14 3 B Y1 13 C Y2 12 Y3 11 6 Y4 10 4 G1 Y5 9 5 G2A Y6 7 G2B Y7 74LS138

2. Problem 5.82 U1 1 15 2 A Y0 14 3 B Y1 13 C Y2 12 Y3 11 6 Y4 10 4 G1 Y5 9 5 G2A Y6 7 G2B Y7 74LS138

1 3. Design an adder circuit with inputs X1, X0, Y1, Y0 and Cin, and outputs Cout, S1, and S0. To design the circuit, simply write equations for Cout, and S1 as minimal sum of products. For S0 take advantage of XOR gates. You do not have to draw the circuit. Selected terms of the truth table are shown below.

Cin X1 X0 Y1 Y0 Cout S1 S0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 1 2 0 0 0 1 0 0 1 0 3 0 0 0 1 1 0 1 1 4 0 0 1 0 0 0 0 1 5 0 0 1 0 1 0 1 0 6 0 0 1 1 0 7 0 0 1 1 1 8 0 1 0 0 0 9 0 1 0 0 1 10 0 1 0 1 0 11 0 1 0 1 1 12 0 1 1 0 0 13 0 1 1 0 1 14 0 1 1 1 0 15 0 1 1 1 1 16 1 0 0 0 0 17 1 0 0 0 1 18 1 0 0 1 0 0 1 1 19 1 0 0 1 1 1 0 0 20 1 0 1 0 0 0 1 0 21 1 0 1 0 1 22 1 0 1 1 0 23 1 0 1 1 1 24 1 1 0 0 0 25 1 1 0 0 1 26 1 1 0 1 0 27 1 1 0 1 1 28 1 1 1 0 0 29 1 1 1 0 1 30 1 1 1 1 0 31 1 1 1 1 1 You should use the maps shown below for this design

2 Cin = 0 Cin = 1 Cout X1 X1

Y0 Y0 Y1 Y1 X0 X0

Cin = 0 Cin = 1 S1 X1 X1

Y0 Y0 Y1 Y1 X0 X0

Cin = 0 Cin = 1 S0 X1 X1

Y0 Y0 Y1 Y1 X0 X0

3 4. Draw the diagram to show how to realize the functions F(W,X,Y) = (1,3,5,6) and G(W,X,Y) = (2,3,4,7) using only a single 74LS138 and two NAND gates. U1 1 15 2 A Y0 14 3 B Y1 13 C Y2 12 Y3 11 6 Y4 10 4 G1 Y5 9 5 G2A Y6 7 G2B Y7 74LS138 5. Draw the diagram to show how to realize the functions F(A,B,C,D) = (2,4,6,14) using only one 74LS138 and one NAND gates. U1 1 15 2 A Y0 14 3 B Y1 13 C Y2 12 Y3 11 6 Y4 10 4 G1 Y5 9 5 G2A Y6 7 G2B Y7 74LS138

6. Draw the diagram to show how to realize the functions F(A,B,C) = (0,4,6) and G(C,D,E) = (1,2) using only a single 74LS139 IC and two NAND gates. U2A 2 4 3 A Y0 5 B Y1 6 1 Y2 7 G Y3 74LS139

U3B 14 12 13 A Y0 11 B Y1 10 15 Y2 9 G Y3 74LS139

4 7. Draw the diagram to show how to realize the functions F(W,X,Y) = Õ(3,4,5,6,7) using only a 74LS151. U4 4 6 3 D0 W 2 D1 5 1 D2 Y 15 D3 14 D4 13 D5 12 D6 D7 11 10 A 9 B 7 C G 74LS151

8. Draw the diagram to show how to realize the functions F(A,B,C,D) = å(2,4,6,14) using only a 74LS151. U4 4 6 3 D0 W 2 D1 5 1 D2 Y 15 D3 14 D4 13 D5 12 D6 D7 11 10 A 9 B 7 C G 74LS151

Note: You can place a symbol on an OrCAD schematic, select that symbol, copy it to the clipboard, and then past it into a Microsoft Word document, which can be printed out. This will keep you from having to draw everything by hand.