I am having issues when running software placed in the SDRAM. When I run memory tests on the SDRAM with the memory test code running in BRAM, all tests pass. However if I do the same test with the code running in SDRAM the program sometimes succeeds and sometimes crashes. I am being careful and not overwriting any of the code space with the memory tests.
Is there some MPMC setting that could be causing this? Or is there some error with the memory controller that the memory tests are not picking up? (I am using the mpmc_mem_test_example provided by Xilinx) I am trying to run VxWorks, and the code cannot fit into BRAM. The code is running on the PowerPC. I see the same behavior when connecting the PPC to the MPMC with the plb and PPC440MC busses.