Why is the Arria 10 DDR4 MMR signal (mmr_slave_readdatavalid_0) toggling even though there is no user read request?

Description

If the Enable Memory-Mapped Configuration and Status Register (MMR) Interface option is turned ON under the Controller tab of the Arria® 10 DDR4 IP Parameter Editor, you may see the MMR signal (mmr_slave_readdatavalid_0) toggling even though there is no user read request.

Resolution

This problem is scheduled to be fixed in a future release of the Quartus® Prime software.