Explain the working of bcd adder, Computer Engineering

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

Posted Date: 8/31/2013 3:48:17 AM | Location : United States

Related Discussions:- Explain the working of bcd adder, Assignment Help, Ask Question on Explain the working of bcd adder, Get Answer, Expert's Help, Explain the working of bcd adder Discussions

Write discussion on Explain the working of bcd adder
Your posts are moderated
Related Questions
Analysis describes about the logical and statistical analysis needed for an efficient output. This involves writing of code and performing calculations, but most part of these lang

Now let's define range which a normalised mantissa can signify. Let's presume that our present representations has normalised mantissa so left most bit can't be zero so it has to b

State about the Object models Object models are used for explaining the objects in the system and their connection with each other in the system. The dynamic model explains in

What is the function of in network access layer in TCP/IP protocol stack? Function of Network Access Layer: The network access layer is the lowest layer within Internet

What are the characteristics and features of Client/Server Computing? Several of client/server computing architecture is listed below: a. It comprises a networked webs of sm

What tag do you use to add a hyperlink column to the DataGrid?   Anchor tag is used to add a hyperlink column to the data grid

"Global business-to-consumer e-commerce sales will pass the 1 trillion euro ($1.25 trillion) mark by 2013, and the total number of Internet users will increase to approximately 3.5

Orbix is a CORBA ORB (Object Resource Broker) - a commercial software product which helps programmers builds distributed applications. Orbix is an execution of the OMG's (Object Ma

Determine the salient features of a parallel programmable interface, 8255. 24 I/O lines in 3 8-bit port groups - A, B, C A, B can be 8-bit input or output ports C