Altera FFT MegaCore Function - Manual (Page 37)

Figure 3-12: FFT Burst Data Flow Simulation Waveform
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EXP0 EXP1 EXP2
clk
reset_n
sink_valid
sink_ready
sink_sop
sink_eop
inverse
sink_real
sink_imag
source_real
source_imag
source_exp
source_ready
source_valid
source_sop
source_eop
In a burst I/O data flow FFT, the FFT can process a single input block only. A small FIFO buffer at the
sink of the block and
sink_ready
is not deasserted until this FIFO buffer is full. You can provide a small
number of additional input samples associated with the subsequent input block. You don’t have to
provide data to the FFT during
sink_ready
cycles. The burst FFT can load the rest of the subsequent FFT
frame only when the previous transform is fully unloaded.
RT** For information about enabling the buffered burst FFT, refer to
Enabling the Streaming FFT .
Related Information
Enabling the Streaming FFT on page 3-7
FFT IP Core Parameters
Table 3-4: Basic Parameters
Parameter Value Description
Transform Length 64, 128, 256, 512,
1024, 2048, 4096,
8192, 16384, 32768,
or 65536. Variable
streaming also
allows 8, 16, 32,
131072, and 262144.
The transform length. For variable streaming, this
value is the maximum FFT length.
Transform Direction Forward, reverse,
bidirectional
The transform direction.
3-14 FFT IP Core Parameters
UG-FFT
2014.12.15
Altera Corporation FFT IP Core Functional Description
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