Design of Novel Reversible Carry LookAhead BCD Subtractor

1
Design of Novel Reversible Carry Look-Ahead BCD
Subtractor

• Thapliyal, Himanshu Gupta, Sumedha K, Design of
  Novel Reversible Carry Look-Ahead BCD
  Subtractor. ICIT '06. 9th International
  Conference on Information Technology, pp . 253
  258 , Dec. 2006.
• Advisor Dr . Shu-Chung Yi
• Author Shi-Xun Chang

2
Outline

• 1 . Introduction
• 2 . BCD Subtractor
• 3 . Carry Look Ahead Adder
• 4 . Reversible Carry Look-Ahead BCD Subtractor
• 5 . Conclusions

3
Introduction

• The decimal arithmetic is receiving
  significant attention as the financial,commercial,
  and internet-based application can not tolerate
  errors generated by conversion between decimal
  and binary formats?

4
BCD Subtractor

• In the BCD subtraction,nines complement of
  the subtrahend is added to the minuend ?In BCD
  arithmetic ,instead of subtracting the number
  from nine ,the Nines complement of a number is
  determined by adding 1010 (decimal 10) to the
  ones complement of the number ?

5
BCD Subtractor
6
Carry Look Ahead Adder
7
Reversible Carry Look-Ahead BCD Subtractor
8
Conclusions

• The focus of this paper is the IEEE 754r
  considering decimal arithmetic and the promising
  paradigm of reversible logic ?Thus,this paper
  proposes novel carry look-ahead BCD subtractor
  along with its optimal reversible logic
  implementation ?