wrong FFT output-data?!

Hello,

I hope somebody can help me.

First my configuration:

Cyclone III Starter Kit

FFT v8.0 with 1024 points

burst

14 bit resolution

32MHz clock

2MHz output clock (after FIFO)

Ok, how should I start. I've got two problems:

1. the reset!

When do I have to do a reset? Once after programming the device, e.g. pushing a button? Or after each FFT run?

2. the scaling!

I read many facts about that, but I think I didn't get it right now. At the FFT User Guide I read the implementation and I don't know, if I understood that right:

example:

14 bit full range, 4 bit (1001) word, shifting 4 times

result:

111111 1001 0000

100000 1001 0000

000000 1001 0000

Which of these results is the correct one?

I programmed my device and put a sinus on the ADC-board. From here it goes onto the FPGA, into the FFT-real-input.

My results look like the attached picture. The MSB are always "1" or "0" at the same time :confused:

I tried so much and I don't know what to do more. I also attached my "shifter.vhd"-file, which handles the scaling.

Thanks for your help!

Lars :(