When using a custom arbitration mode, the MPMC GUI allows a selection of only 10 or 12 slots. This overrides the user C_ARB0_NUM_SLOTS parameter.
How do I resolve this issue?
A possible work-around is to manually change the C_ARB0_NUM_SLOTS parameter if it is overridden by the GUI. Each relevant C_ARB0_SLOT<Num> parameter will also need to be manually set in the MHS. Note that 10 or 12 slots is the correct value for Spartan-6 FPGA.
This issue is scheduled to be fixed in MPMC v5.04.a, to be released in EDK 11.4.