When the input sampling Rate is above the clock frequency of the processor (Super Sampling Rate), samples must be acquired in parallel. For a 2 Gsps input sample rate, you can specify that the filter should receive two samples at a 1 GHz rate, which can be seen as two data streams (Polyphase decomposition), each one at 1 Gsps. Because the AI Engine array AXI-Stream network is limited to 1 GHz (slowest speed grade), the high sampling rate input (above 1 Gsps) is to be decomposed into multiple phases to be processed.
As a first example, suppose there is a 2 Gsps data stream to be processed, it can be split into two phases to be routed to the AI Engine array:
A 5 Gsps data stream must be split into 5 phases: