Burst transfers from an Avalon®-MM master which has the lineWrap parameter set may access the incorrect addresses when the burst begins from an address which is not aligned with a burst boundary.
This problem occurs when there are 2 or more Avalon-MM masters connected to a slave.
The problem causes the Qsys fabric to miscalculate the burst boundary and so not wrap at a burst boundary.
For more information on the lineWrap parameter, refer to chapter 3 of the Avalon Interface Specifications (PDF).
An example of an Avalon-MM master with the lineWrap parameter enabled is the Nios® II instruction_master.