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.
Note
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.