Design a Bcd-to-excess-3 Code Converter Using a Rom

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ROM design for BCD to Excess 3 converter

• Thread starter VPrasanth
• Start date Aug 13, 2014

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Hi

i need to design a ROM for BCD to Excess 3 Code converter using Mealy State Diagram, Can anyone please solve this for me

• #2

Homework alert for a lazy student. Do your own work or change your studies to art appreciation.

We'll help if you get stuck, but don't ask us to do your work for you.

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Homework alert for a lazy student. Do your own work or change your studies to art appreciation.

We'll help if you get stuck, but don't ask us to do your work for you.

its not like that i dont know the answer but its a tricky question if you know the answer tell me otherwise dont give me suggestions, i want other opinions on this thats all, for your kind info its a research based question

• #4

So how about giving us your own research results so far. That way we don't have to duplicate what you already know. Or were you expecting people to waste their time telling you things you already know?

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So how about giving us your own research results so far. That way we don't have to duplicate what you already know. Or were you expecting people to waste their time telling you things you already know?

Dont get me wrong, well basic theory is we can convert BCD to Excess 3 using Simple logic of Boolean Expression and K-Maps, but here the question is using Mealy State Diagram where it depends on current state and the current inputs, here is the link BCD to Excess 3, but the problem is how to design it with ROM when no inputs and outputs are specified, in the mealy state it was only summarized that for 4 time instances what could be the next state and output, i want it to be design it in ROM, i hope you got my point

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sorry for my attitude, i am doing my Ph.D in the area of VLSI, i have done my homework related to this problem i know the solution and sorry for not providing it, basically i want to design ROM from a mealy circuit, which is part of my work the problem is here how to convert that state diagram into ROM when no inputs and outputs are specified, well i tried so many option but nothing is correct

• #8

So let me get this straight. You want to perform the serial mealy FSM using a ROM, but don't know how to convert it?

Yeah, I know how to do that. I used to design all my FSMs using this technique back when programmable logic (PALs) were all OTP and very expensive. ROMs were way cheaper.

As you are studying for a PH.D I think that you, of all people, would know exactly how to ask a question without looking like a lazy student.

• #9

I think the formal definition of the Mealey machine will directly lead to a mapping from present states x input alphabetes to next states and output alphabet, which can be coded in a ROM. https://en.wikipedia.org/wiki/Mealy_machine

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So let me get this straight. You want to perform the serial mealy FSM using a ROM, but don't know how to convert it?

Yeah, I know how to do that. I used to design all my FSMs using this technique back when programmable logic (PALs) were all OTP and very expensive. ROMs were way cheaper.

As you are studying for a PH.D I think that you, of all people, would know exactly how to ask a question without looking like a lazy student.

yeah i know that but it was a part of my code which i have to use ROM as you might know that we have BCD inputs and EXcess-3 code outputs, so total 4 inputs and 4 outputs, but after getting mealy state diagram and state table, what might be the inputs/outputs

• #11

yeah i know that but it was a part of my code which i have to use ROM as you might know that we have BCD inputs and EXcess-3 code outputs, so total 4 inputs and 4 outputs, but after getting mealy state diagram and state table, what might be the inputs/outputs

What you posted in #5 was a serial implementation, are you saying you want a parallel implementation? You're not giving a very clear concise explanation of what you are trying to accomplish. In fact you haven't done so for this entire thread.

You keep saying you have no inputs and outputs specified, but then you come back and say you have 4 inputs and 4 outputs, so which is it? Do you have inputs and outputs or don't you?

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sorry for not making you clear about my doubt, but i got the answer i will post it so you can summarize what i want

- - - Updated - - -

here is the answer

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Design a Bcd-to-excess-3 Code Converter Using a Rom

Source: https://www.edaboard.com/threads/rom-design-for-bcd-to-excess-3-converter.321187/

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