FFTcore input format

Hi,

Im trying to implement crosscorrelation in verilog on a stratix III. Using the megacore fft, i have done all the work with fft->conjugate->multiplication but now that i need to do the IFFT i can't figure out how to interface it.

The manual to the fftcore states the following:

data is input to the fft function as fixed point complex numbers (even though the exponent is effectively 0, you do not enter an exponent).

But where is the radix point in this fixed point number, i can't find it anywhere! Since the output is in block floating format, i have done all my calculations upon those and now i need to convert the block floating into fixed point to input it into the (i)fft.

Anyone that knows hos this can be done, has any examples or at least know where the radix point is at the input?