Champs,
AM57x TRM states that VPDMA engine has internal memory for storing descriptors' List that is being processed. Is it possible to know the size of this memory/how many descriptors can fit there at a time?
thanks,
Michael
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Champs,
AM57x TRM states that VPDMA engine has internal memory for storing descriptors' List that is being processed. Is it possible to know the size of this memory/how many descriptors can fit there at a time?
thanks,
Michael
rogerio said:1) Can you provide some insight into the depth of the internal buffering for frame data in the VPDMA (assuming a frame width of 2112 bytes) so that we can figure out how many flush lines we need to ensure that we “push through” image data into the DDR. We plan on using a strategy of pausing capture in the middle of a frame, so we need to be able to flush the data out of the VPDMA with additional lines rather than using the vsync to force the flush.
No flushing is needed. VPDMA will keep writing to the DDR irrespective of pixel data coming to the VIP/parser.
rogerio said:2) Is there a maximum frame length for the video port? We plan on using a frame width of 2112 (and 2880 in 200dpi mode), but we are not sure how big we can set the frame length to. The way we see it, the longer the frame the better, because it would reduce the number of descriptors needing to be set up. Can you think of any reason not to use the maximum frame length?
No restriction on the frame length for the video port from VIP IP side. Only frame width has restriction on 8K bytes (and not pixels). Refer to the TRM. Software driver (linux/RTOS) may have internal restrictions on frame height that need to be looked from the individual driver perspective. VIP linux driver has max height restriction of 1536 lines.