There is an inconsistency in the OPB PCI bridge operation when simultaneous OPB-side and PCI-side peripheral reads occur. Depending on the relative timing, an OPB timeout can occur. Although this is an allowed OPB protocol, it is inconsistent in operation. In earlier versions, an OPB timeout occurred for certain relative clock phases.
To solve this issue, make sure that OPB retry occurs consistently with all clock phases with simultaneous OPB-side and PCI-side reads. To resolve this issue, you can download a patch located at:
Download the patch to the "pcore" sub-directory (in your project directory) and compile the design.
NOTE: This patch has the same version as the existing core in the EDK build.
A resolution is included in 8.1i EDK, scheduled for release in 2006.