The prototype is slightly different from the AXI DMA designs by modifying the following:
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Removing the loopback connection between TX and RX.
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The RX path has multiple Data generators intended to provide a simple identifiable data pattern to the user based on the channel chosen. If the DMA channel is not set up to receive data, the RX path will drop the data. The data generators head into an AXI Stream Switch IP before heading directly into the MCDMA IP.
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The TX path provides a terminated path that can be viewed with an ILA, if desired. The tready signal is tied high. Filtering on TDEST would show the data stream on each channel.
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The RX interface of the MCDMA never throttles. This means when a channel provides data and the channel is not enabled, the data will be dropped. This is done intentionally by the IP so a channel will not throttle the rest of the channels. However, care must be taken if all RX data needs to be captured.
This article also doesn’t walk a user through the entire flow and relies on PetaLinux experience on how to add an application and/or module into a running Linux system. Modifying the device tree is also required.