When the upstream master is active and sending frame data
to the core, it becomes difficult to use the previous technique to synchronize configuration
with particular frames because data for a new frame might have already been loaded into the
Data Input channel. The recommended way of synchronizing configuration to frames is to use the
event_frame_started signal.
This signal is asserted High when the core starts to load
data for a frame into the FFT processing core. This is a known safe point to send
configuration information for the next frame. Configuration data sent after this might or
might not be applied to the subsequent frame, depending on the frame size and the latency
between event_frame_started asserting and the configuration write
occurring.