FFT Processing in OFDM Signal Demod Urgent HELP!!!

Started by Unknown February 4, 2005

I\'m a 5th yr student at a college of technology in Japan. I am currently doing an experiment regarding OFDM signal Demodulation using FFT procedures. I am using TMS320C6713 DSK as my platform. I adopted a sample project called FFT6713 which is included on the documentation and libraries.
I want to perform FFT on real input signal and obtain the real and imaginary results. The input signal is to be sampled at the rate of 32Khz and the number of points is 1024. This could be easily done using the said sample project above. However, my main problem is setting an external interrupt (EXTINT4) that will signal the DSP to start sampling the input the moment the interrupt changes from low to high (then perform FFT after obtaing 1024 samples). And after 32ms, (1/31.25Hz which is the time enough to get 1024 pts at 32KHz) the input buffercounter is set again to 0 so that the next 1024 samples can be written again( from 0 to 1023(address) of input buffer sequentially). The external interrupt comes from the sync of the function generator and is set to 31.25Hz (the interrupt pulse signals the DSP every 32ms).
I am very new in using the TMS320C6713, and just started a month ago. I will warmly appreciate any technical advise, codes, dsp/bios configurations or any help for the solution of my problem. THANK YOU VERY MUCH in advance and more power to this group. Also looking forward to meeting new friend from around the world!!!