Sundance FC100 v.2.3 - Manual (Page 14)

FC100 - Floating Point Fast Fourier Transform
v2.3
Fast Fourier Transform product manual
October 2005 www.sundance.com - 14 -
Waveforms
Start
Figure 4: Start
Figure 3 shows how the FFT core must be started. The start signal is driven high for one
clock cycle. The first address for the data and twiddles is generated after 7 clock cycles.
The user then fetches the twiddles and data in the memory and drives the signal
tw_din_valid high. A new data and twiddle are then expected every new clock cycle.