How to design a BCD Subtractor?

Replies

• 

  Kaustubh Katdare

  Post moved to a new thread in Electrical/Electronics engineering section.
• 

  cooltwins

  there are two options......(according to what we are taught in our 2nd year,dunno if its what you ask any way here it goes.)
  1)using 9's complement
  2)using 10's complement.
• 

  cooltwins

  the mechanism of 9's complement is like this:
  regular sub: ............ 9's comp. sub:
  8 ......................................... 8
  -2...................................... +7 (removal of 2 from 9)
  ---..................................... -----
  6...................................... 1 5 => 1+5 = 6
  
  in case of 10's complement:
  regular ....................... 10's comp. sub:
  8............................................ 8
  -2....................................... +8 (removal of 2 from 10)
  ----..................................... -----
  6......................................... 1 6
  ........................................... now drop the carry and the result of sub. is 6
  
  this is the basic logic
• 

  cooltwins

  if this is what you ask then let me know i can try and get you the circuit.😀
• 

  vishnu priya

  I am dealing with the same topic..
  
  Will let you know the answer soon,because i am working for it right now.
• 

  cooltwins

  sorry i am unable to do so
  it is in my text but you may try and find the book in some library(sorry about that!!!)
  BOOK: digital electronics(first edition)
  AUTHORS:A.P.Godse ,D.A.Godse
  PUBLICATIONS:technical publication, pune.
  
  you may also try other books but this is the prescribed one for 2nd year in my college.
  it has the circuit for both 9's and 10's complement.
• 

  shreya_rulz

  hey u must be a student of pune university then....use tech max.borrow it from a friend if you dont have it.i had studied from the techmax book by J.S.Katre.the topic is very well covered in that book.