Endpoint Block Plus Wrapper v1.9 for PCI Express - Completion dropped and receiver overflow on RX interface when using completion streaming mode
Description
Keywords: Completion Streaming, completion lost, channel switch, posted, non-posted
Known Issue: v1.9.2, v1.9.1, v1.9, v1.8, v1.7.1, v1.7, v1.6.1, v1.6
Under some conditions, when completion streaming is used, it is possible that a completion packet may get dropped and a receiver buffer overflow will occur.
Solution
There was a problem in the logic that implements the completion streaming mode, where under some conditions, if there are multiple posted or non-posted packets being received during the completion stream, the block plus wrapper logic was not efficiently switching channels to drain these packets from the integrated block. This would then cause completions to back up in the integrated block, eventually resulting in an overflow. When this happens, cfg_dstatus[2] asserts to a 1 indicating a fatal error condition. Also, users may notice that a completion has been lost.A fix for this is available in the v1.9 Rev 3 patch. See (Xilinx Answer 31572) for access to the patch.
Revision History
02/25/2009 - Initial release