How Many DMA FIFOs are Available on CompactRIO Platforms?Hardware: CompactRIO
Problem: I would like to use Direct Memory Access (DMA) to transfer data from my FPGA target to my real-time host or vice versa. How many channels are available to do this on the CompactRIO (cRIO) platform? Solution: All cRIO platforms have three DMA channels. Selection of the DMA channel is done automatically in LabVIEW 8.6 FPGA Module and above. You may have more than three DMA FIFOs defined in the Project Explorer, but if you attempt to compile an FPGA VI that contains more than three DMA FIFOs you will receive the following error. There are insufficient DMA channels available on the current target. Too many DMA channels have been requested or some channel requests are conflicting. The current target has 3 DMA channels. Review the list of requested channels and remove one or more to free up resources.Related Links: LabVIEW 8.6 FPGA Module Help: Creating FPGA FIFOs (FPGA Module) LabVIEW FPGA Module Release and Upgrade Notes Version 8.6 KnowledgeBase 4767OILX: Allocating DMA Memory on cRIO Controllers with 128 MB DRAM Can Cause the Controller to Crash Attachments:
Report Date: 05/18/2009 Last Updated: 05/19/2009 Document ID: 4XHBCJYP |
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