Mem, thanks for your reply.

The routine does the fast Fourier transform of an array of data. The fact is that it is not a product of mine, and I'm not so fluent in reading and understanding assembler. So I would like to use it as is, but it's kinda long (~600 lines) to be included with the asm directive.

Of course I could write a new routine by my own, but I'm used to be lazy, you know, and moreover looks like that routine (named avrfft) scores quite good in terms of efficiency.

Thanks again,

-P.