This document discusses energy efficient code converters using reversible logic gates. It outlines the drawbacks of irreversible computing such as energy dissipation and information loss. Reversible computing is more energy efficient and improves performance by recovering inputs from outputs. Code converters are used for encryption and decryption and allow for portability and tractability. A BCD to excess-3 converter is presented along with its truth table and block diagram. Reversible gates like the Feynman gate and NG gate are also discussed. The advantages of reversible gates include less energy dissipation and heat management. Designing reversible circuits is complex as garbage outputs must be minimized and loops and fan-out are not permitted. Reversible logic can be applied to code converters,

1. ENERGY EFFICIENT CODE
CONVERTERS USING
REVERSIBLE LOGIC GATES
Presented by :
B. Aditya Kumar

2. Outline
 Drawbacks of Irreversible Computing
 Advantages of Reversible Computing
 Code Converters
 BCD to Excess-3 Converter
 Advantages and Design Complexity of
reversible logic

3. Irreversible Computing
 Energy dissipation
 Information loss
 Components degradation

4. Reversible Computing
 Energy Efficient
 Improve Performance
 Inputs recovered from outputs

5. Code Converters
 Used for Encryption and Decryption
 Portability
 Tractability

6. BCD to Excess-3 Converter Truth
Table

7. Block diagram of BCD to Excess-3
Code Convertor

8. Feynman Gate

9. Feynman Gate Truth Table
Outputs:
P = A
Q = A xor B

10. NG gate
 3*3 reversible gate
 Inputs: A,B,C
 Output: P = A;
Q = A xor B xor C;
R = AB+BC+CA;

11. Advantages of Reversible gates
 Energy dissipation is less
 Heat management
 Duplication of Input through Output
 Power management

12. Design complexity of Reversible
circuit
 Garbage outputs should be minimum
 Complex task to design a reversible logic
 Loops are not permitted
 No Fan-out

13. Applications
 Can be used in Code converters and
binary incrementers.
 Can be used in nanotechnology.
 Can be used in low power CMOS
circuits.

14. References:
 [1] Manjula Gandhi S, J Devishree “Design of
Reversible Code Converters for Quantum Computer
based system” proceedings published by International
Journal of Computer Applications.
 [2] Generation in computational process, IBM J.
Research and Development,5: 183-191.
 [3] Bennet, C.H.,1973.Logical Reversibility of
Computation, IBM J Research and Development ,pp:
525-532.
 [4] Haghparast, M. and K. Navi, 2008. Design of a
Novel Fault Tolerant Reversible Full Adder For
Nanotechnology Based Systems, World Applied
Science Journal3(1): 144-188.