4 bit add sub

1. Hanbat
Hanbat
National
National
University
University
4-Bit Adder-Subtractor4-Bit Adder-Subtractor
Gookyi Dennis A. N.Gookyi Dennis A. N.
SoC Design Lab.SoC Design Lab.
June.19.2014

2. ContentsContents
Implementation of Half-Adder
Implementation of Full-Adder
Implementation of 4-Bit Adder-Subtractor
2

3. Implementation of Half AdderImplementation of Half Adder
Truth table
Circuit diagram
3
input1 input2 sum Carry
0 0 0 0
0 1 1 0
1 0 1 0
1 1 0 1

4. Implementation of Half AdderImplementation of Half Adder
Half-Adder module
4

5. Implementation of Half AdderImplementation of Half Adder
Half-Adder RTL schematic
5

6. Implementation of Full AdderImplementation of Full Adder
Truth table
6
input1 input2Carry_in sum Carry_out
0 0 0 0 0
0 0 1 1 0
0 1 0 1 0
0 1 1 0 1
1 0 0 1 0
1 0 1 0 1
1 1 0 0 1
1 1 1 1 1

7. Implementation of Full AdderImplementation of Full Adder
Circuit diagram
7

8. Implementation of Full AdderImplementation of Full Adder
Full-Adder module
8

9. Implementation of Full AdderImplementation of Full Adder
Full-Adder RTL schematic
9

10. Implementation of 4-Bit Adder-SubImplementation of 4-Bit Adder-Sub
Block diagram
10

11. Implementation of 4-Bit Adder-SubImplementation of 4-Bit Adder-Sub
Flow chart
11
START
PERFORM
SUBTRACTIO
N
PERFORM
ADDITION
CARRY_IN == 1? YESNO

12. Implementation of 4-Bit Adder-SubImplementation of 4-Bit Adder-Sub
4-Bit Adder-Sub module
12

13. Implementation of 4-Bit Adder-SubImplementation of 4-Bit Adder-Sub
4-Bit Adder-Sub testbench
13

14. Implementation of 4-Bit Adder-SubImplementation of 4-Bit Adder-Sub
4-Bit Adder-Sub waveform
14

15. Implementation of 4-Bit Adder-SubImplementation of 4-Bit Adder-Sub
4-Bit Adder-Sub RTL schematic
15