Technical discussions about the TI C54x DSPs (including the c5401, c5402, c5402a, c5404, c5407, c5409, c5409a, c5410, c5410a, c5416, c5420, c5421, c5441, c549, c5470 and c5471).
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Hi all, I am using the cfft and rfft functions from the TI's DSPLIB. It is mentioned in TI's App Notes (SPRU518) that the code size of both functions is about 370 words (plus anoth 360 words for the sintab). However, my output code size increases by nearly 5K if I use once either of these two functions. Does anyone know the reason behind this ? Thank you very much. Dww Knowles Electronics Inc. |
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Hi It is probably the .sintab section. If you look in your .map file, you will see that a .sintab section is included if you use the cfft. If you look at the cfft source code, you will see that it includes a sintab.q15 file which is used for the FFT. Best regards Torgeir Jakobsen Senior Engineer, Technology Department Aanderaa Instruments AS e-mail: web: www.aanderaa.com phone; +47 55 10 99 00 direct: +47 55 10 99 77 fax: +47 55 10 99 10 ----- Original Message ----- From: "wei_wen_dai" <> To: <> Sent: Saturday, February 02, 2002 6:13 AM Subject: [c54x] size of FFT code from DSPLIB > Hi all, > > I am using the cfft and rfft functions from the TI's DSPLIB. > It is mentioned in TI's App Notes (SPRU518) that the code size of > both functions is about 370 words (plus anoth 360 words for the > sintab). However, my output code size increases by nearly 5K if I use > once either of these two functions. > > Does anyone know the reason behind this ? > > Thank you very much. > > Dww > Knowles Electronics Inc. > > _____________________________________ |
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I don't know for sure, but it seems to be highly unlikely that sin table would occupy over 4kbytes (2kwords) of space. I'd expect it to be in order of 256-512 bytes or less. Mike. On 2/4/02 11:22 AM, "Torgeir Jakobsen" <> wrote: > Hi > > It is probably the .sintab section. If you look in your .map file, you will > see that > a .sintab section is included if you use the cfft. If you look at the cfft > source code, > you will see that it includes a sintab.q15 file which is used for the FFT. > Best regards > Torgeir Jakobsen > Senior Engineer, Technology Department > Aanderaa Instruments AS > e-mail: > web: www.aanderaa.com > phone; +47 55 10 99 00 > direct: +47 55 10 99 77 > fax: +47 55 10 99 10 |
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Wei Wen Dai- >I am using the cfft and rfft functions from the TI's DSPLIB. >It is mentioned in TI's App Notes (SPRU518) that the code size of >both functions is about 370 words (plus anoth 360 words for the >sintab). However, my output code size increases by nearly 5K if I use >once either of these two functions. > >Does anyone know the reason behind this ? Is it possible that including the cfft and rfft functions in turn cause some additional functions from rts.lib, rts_ext.lib, or other C5000 library files to be included in your build? Jeff Brower DSP sw/hw engineer Signalogic |
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Hi I have checked the size of the sintab table. The complete size is 1517 words or 3034 bytes. Best regards Torgeir Jakobsen Senior Engineer, Technology Department Aanderaa Instruments AS e-mail: web: www.aanderaa.com phone; +47 55 10 99 00 direct: +47 55 10 99 77 fax: +47 55 10 99 10 ----- Original Message ----- From: "Mikhail Fridberg" <> To: <> Sent: Monday, February 04, 2002 7:39 PM Subject: Re: [c54x] size of FFT code from DSPLIB > I don't know for sure, but it seems to be highly unlikely that sin table > would occupy over 4kbytes (2kwords) of space. I'd expect it to be in order > of 256-512 bytes or less. > > Mike. > > On 2/4/02 11:22 AM, "Torgeir Jakobsen" <> wrote: > > > Hi > > > > It is probably the .sintab section. If you look in your .map file, you will > > see that > > a .sintab section is included if you use the cfft. If you look at the cfft > > source code, > > you will see that it includes a sintab.q15 file which is used for the FFT. > > > > > > Best regards > > Torgeir Jakobsen > > Senior Engineer, Technology Department > > Aanderaa Instruments AS > > e-mail: > > web: www.aanderaa.com > > phone; +47 55 10 99 00 > > direct: +47 55 10 99 77 > > fax: +47 55 10 99 10 > > _____________________________________ |