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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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size of FFT code from DSPLIB
Started by ●February 2, 2002
Reply by ●February 4, 20022002-02-04
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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. > > _____________________________________ > Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. You need to do a "reply all" if you want your answer to be distributed to the entire group. > > _____________________________________ > About this discussion group: > > To Join: Send an email to > > To Post: Send an email to > > To Leave: Send an email to > > Archives: http://www.yahoogroups.com/group/c54x > > Other Groups: http://www.dsprelated.com > ">http://docs.yahoo.com/info/terms/ |
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Reply by ●February 4, 20022002-02-04
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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 |
Reply by ●February 4, 20022002-02-04
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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 |
Reply by ●February 5, 20022002-02-05
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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 > > _____________________________________ > Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. You need to do a "reply all" if you want your answer to be distributed to the entire group. > > _____________________________________ > About this discussion group: > > To Join: Send an email to > > To Post: Send an email to > > To Leave: Send an email to > > Archives: http://www.yahoogroups.com/group/c54x > > Other Groups: http://www.dsprelated.com > ">http://docs.yahoo.com/info/terms/ |
