The relationship between descriptor SOF/EOF settings and the AXI Control Stream is illustrated in the following figure. The descriptor with SOF=1 is the beginning of the packet and resets DRE for the MM2S direction. The User Application fields for this descriptor are also presented on the AXI Control Stream if the Status/Control Stream is enabled. User Application fields following a descriptor with SOF=1, up to and including the descriptor with EOF =1, are ignored by the AXI DMA engine. If Status/Control Stream is disabled, the User Application fields are not fetched by the SG Fetch Engine.
Figure 1. Detail of Descriptor Relationship to MM2S Stream and Control
Stream
