Stream Input for Asymmetric FIRs - 2023.2 English

Vitis Libraries

Release Date
2023.2 English

Stream input allows data samples to be written directly from the input stream to one of the Input Vector Registers without the requirement for a ping-pong window buffer. As a result, memory requirements and latency are reduced.

To maximize the throughput, FIRs can be configured with 2 input stream ports. Although this may not improve performance if the throughput is limited by other factors, i.e., the output stream bandwidth or the vector processor. Set TP_DUAL_IP to 1, to create a FIR instance with 2 input stream ports. In such a case the input data will be merged from the two ports in 128 bit chunks, onto one data stream internally, e.g.:

  • samples 0-3 to be received on input stream 0 for cint16 data type,
  • samples 4-7 to be received on input stream 1 for cint16 data type.


For the single rate asymmetric option dual input streams offer no throughput gain if a single output stream is used. Therefore, dual input streams are only supported with 2 output streams.