Explain the working of bcd adder, Computer Engineering

Assignment Help:

Explain the working of BCD adder

One of the ways of adding decimal numbers in BCD is to use a 4-bit binary adder and perform arithmetic operation one digit at a time. The low-order pair of the BCD digits is first added to generate a binary sum if result is equal or greater than 1010, it is corrected by adding 0110 to the binary sum. The second operation produces an output- carry for the next pair of important digits. The next higher-order pair of digits, jointly with input-carry, is then added to produce their binary sum. If result is equal to or greater than 1010, it can corrected by adding 0110. The procedure is repeated until all the decimal digits are added.

The logic circuit which detects necessary correction can be derived from table entries. It is clear that a correction is needed when binary sum has an output carry K = 1. The other six combinations from 1010 to 1111 which need a correction have a 1 in position Z . To distinguish them from binary 1000 and 1001 that also have a8 1 in position Z , we specify further that either Z  or Z  must have the1. The condition for8 4 2 correction and an output-carry could be expressed by Boolean function

C = K + Z  Z  + Z  Z8 4 8 2

When C = 1, we require to add 0110 to binary sum and provide an output-carry for next stage.

BCD adder is circuit which adds two BCD digits in parallel and generates sum digit also in BCD. BCD adder must include correction logic in its internal construction

 

934_bcd adder.png


Related Discussions:- Explain the working of bcd adder

What are universal gates, What  are  universal  gates.  Construct  a  lo...

What  are  universal  gates.  Construct  a  logic  circuit  using  NAND  gates  only  for  the expression x = A . (B + C). Ans. Universal Gates: NAND and NOR Gates both are t

Difference between abstract class and interface, Abstract class: Abstract c...

Abstract class: Abstract classes are the class where one or more methods are abstract but not essentially all method has to be abstract. Abstract methods are the methods, which are

Interrupt and scanning method of keypad operation, INTERRUPT METHOD - USING...

INTERRUPT METHOD - USING PORTB CHANGE INTERRUPT By using 4 by 4 matrix keypad connected to PORTA and PORTB. The rows are connected to PORTA-Low (RA1-RA4) and the columns are co

Mobility management in mobile systems, Instruction 1. You can do this i...

Instruction 1. You can do this individually or in groups of 2-3 students. 2. Any material copied and pasted from anywhere (e.g., figures and text) is considered plagiarism even

The average height or weight, A script kept information on potential subjec...

A script kept information on potential subjects for an experiment in a vector of structures known as "subjects".  The following show an example of what the contents may be: >> subj

Method of spirit duplicating, Method : The master from which the copies wi...

Method : The master from which the copies will be taken is first prepared from a special non-absorbent glazed sheet of paper and special carbon paper which acts as the reproducing

Define TII, TII stands for? Ans. TII stands for Table of incomplete ins...

TII stands for? Ans. TII stands for Table of incomplete instructions.

Illustration to demonstrate design of sequential circuits, Q. Illustration ...

Q. Illustration to demonstrate design of sequential circuits? Let us take an illustration to demonstrate above process. Suppose we want to design 2-bit binary counter employing

What is telex, Telex is a (A)  Telephone Service between various subsc...

Telex is a (A)  Telephone Service between various subscribers (B)  Tele printer Service between various subscribers (C)  Television Service between various subscri

An append structure with pooled or cluster tables, Can we include customizi...

Can we include customizing include or an append structure with Pooled or Cluster tables? No.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd