Solving Binary Addition with 4-Bit Full Adder and Decoders

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Discussion Overview

The discussion revolves around the implementation of binary addition using two 4-bit full adders and decoders, with the goal of converting the binary result to decimal for display on seven-segment displays. Participants explore the arrangement of outputs and the limitations of BCD (Binary-Coded Decimal) representation in this context.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant describes their setup involving two 4-bit full adders and two decoders, seeking guidance on how to arrange the output pins to correctly display the decimal equivalent on seven segments.
  • Another participant questions how to separate the tens and hundreds in the BCD representation.
  • A participant mentions successfully displaying numbers up to 9 but expresses uncertainty about how to display numbers beyond that, particularly how to represent 255 using the outputs from the full adders.
  • It is noted that a single 4-bit full adder can represent values from 0 to 15, while two can represent values from 0 to 255.
  • One participant argues that it is impossible to represent 255 using BCD-to-7-segment conversion due to the limitation of BCD handling only values from 0 to 9, suggesting that additional 4-bit BCD counters may be necessary.
  • Another participant counters that certain binary additions can yield the maximum value of 255, indicating a potential misunderstanding of the BCD conversion process.
  • Participants request further clarification and guidance on how to proceed with their implementation.

Areas of Agreement / Disagreement

There is no consensus on the feasibility of displaying the number 255 using the current setup. Participants express differing views on the limitations of BCD representation and the necessary components for achieving the desired output.

Contextual Notes

Participants highlight the limitations of BCD-to-7-segment conversion and the need for additional components to handle values beyond the standard BCD range. There are unresolved questions regarding the arrangement of outputs from the full adders and the handling of carry values.

zeroground
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1. if i i have two "4 bit full adders" and two decoders and three seven segments and i wanted to add numbers in binary with the input and convert it to decimal and show it on the seven segments


2. i did everything and i put the "Carry out" from the first adder into the "Carry in" of the second adder But there's a problem facing me the pins "S0,S1,S2,S3" and "S4,S5,S6,S7" from the full adders how can i arrange them to show the number on the right way

this is urgent ...
thnx
 
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i mean how can i put them in the two BCDs ?
How can i put the tenth alone and the hunder's alone ?
 
zeroground said:
1. if i i have two "4 bit full adders" and two decoders and three seven segments and i wanted to add numbers in binary and converting it to decimal by using bcd decoder and show it on the seven segment


2. i did succeeded to show till number 9 ...But after 9 how it will work ?
i did everything and i put the "Carry out" from the first adder into the "Carry in" of the second adder But there's a problem facing me that the pins "S0,S1,S2,S3" and "S4,S5,S6,S7" from the full adders how can i arrange them in the 2 decoders to show number 255 for example ..

this is urgent ...
thnx

Two "4 bit full adders" can generate a counter from 0-16, how can you generate 0 - 255?
btw, I don't like "urgent" question.:wink:
 
one 4 bit full adder has "S0,S1,S2,S3" which can be 1111 which is 15
two 4 bit full adders has "S0,S1,S2,S3,S4,S5,S6,S7" WHICH can be 11111111 which is 255
 
OK, I understand what's you mean.

I think it's impossible to get '255' from 1111 1111, because a BCD-to-7-segments can only convert the 0000-1001 to 0-9. You can't get any carry if the counter overflow by 10 or 100.

If you have three "4bit-BCD-dec-counter", your problem can be solved.
 
But 11110000 + 00001111 can get 11111111 :)
 
can u tell me what to do ?
 
Hey, Have you ever finish your Task? If not, follow my suggestion I said early, what you need is three "4bit-BCD-dec-counter", Good luck.
 

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