Hi, We are designing a rather complex block which has 3 inputs and 3 outputs. the block is meant to perform packet analisys and injection from two streams so we have 2 inputs and 2 outputs connected to radio rx and tx, and 1 input and 1 output connected to processed packet streams rx/tx.
In order to have enough bandwidth to fit two sample streams in one axi port we are reducing system clock to 120MHz so that cumulative bandwidth (2x120MSPS) is lower than external bus (64bit @166 MHz). This worked pretty well for the receive part but the transmit part seems not to be able to provide enough samples in time and we see that the TX is underflowing. The other strange thing is that when connecting the two stream outputs to two radio TX blocks not only we can't transmit on any but reception on one rx channel stops, while if we connect one of the two outputs to a fifo and then to a null sink we can achieve two inputs and 1 output, although with underflows. While browsing code I found that there has been some recent update related to aligned streams.. is this something that would help? Does anyone have any insight on what may be going wrong? I am supposing some if the issues come from the famous issue with loopback which prevents TX&RX radio blocks to be connected only through rfnoc however my block is not propagating timestamps and it has the two processed packet streams which connect back to host so from what I understand we should not fall in that case. Thanks, Dario Pennisi
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