When the input sampling rate exceeds the processor clock frequency (Super Sampling Rate), the system must acquire samples in parallel. For a 2.5 GSPS input sample rate, you can specify that the filter receives two samples at a 1.25 GHz rate, viewed as two data streams (Polyphase decomposition), each one at 1.25 GSPS. Because the AI Engine array AXI-Stream network is limited to 1.25 GHz (VCK190 device speed grade), the system decomposes high sampling rate inputs (above 1.25 GSPS) into multiple phases for processing.
As a first example, suppose a 2.5 GSPS data stream needs processing. The system splits it into two phases and routes them to the AI Engine array:
A 6.26 GSPS data stream requires splitting into five phases: