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Altera_Forum
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17 years ago

Matlab FFT Vs. DSP Builder FFT

I'v posted a thread in this section, maybe I was wrong, please check it at the following link http://www.alteraforum.com/forum/showthread.php?t=1654&highlight=dsp+fft (http://www.alteraforum.co...
Altera_Forum's avatar
Altera_Forum
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17 years ago

Hi again,

For signed data of a given width, if you want to scale any signed value by 2^n then you should shift magnitude bits towards MSB (n) bits inserting zeros in new LSBs(leading zeros). The sign bit should stay. Ofcourse the datawidth should accomodate these new bits.

If you want to scale by 2^-n you shift magnitude bits towards LSB (n) bits and insert the sign bit in new MSBs(sign extension).

I hope that's what you mean.

kaz