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Valued Contributor III
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decimal fraction

Hi, 

How can I convert the decimal fraction to the mantissa format (IEEE). The MegaWizard function demands the decimal number in binary form (3 = 0011, for example). So how can I convert 0.3 to mantissa without multipling on 10 or 100 etc? Other way, if i starting to multiply so i don't net to use mantissa, am i wright? 

 

My final target is to apply the next math function y = 0.201x + 7.899 

I supplying the "x" values. 

 

Can anybody help me with this question, please?
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Valued Contributor III
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the input is an integer, which will always be binary. But in fixed point, the integer and fractional parts are just normal integers offset by 2^n. Have a read up on fixed point number formats. 

 

Are you sure you want to use flooating point?
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Valued Contributor III
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I am not sure :) 

Are u talkin about the fixed point of MegaWizard? As i remember, it's posibble when i am choosing to use ALTFP_CONVERT. 

 

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Valued Contributor III
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I suggest you read up on fixed point arithmatic 

http://en.wikipedia.org/wiki/fixed-point_arithmetic 

 

All integers are in 2s compliment - there is no decimal representation in any electronics.
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Valued Contributor III
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thanks :) 

I have already read about the fixed point. But i'll do it one more time.
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Valued Contributor III
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--- Quote Start ---  

All integers are in 2s compliment - there is no decimal representation in any electronics. 

--- Quote End ---  

 

 

Not entirely true! 

Some old processors (eg the Singer 'System 10' and its descendent the ICL 'System 25') used BCD arithmetic and addressing.
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