DDR3 controller soft controller IP on Cyclone V GT Nios example design

Hi,

Sorry for late reply.

Upon checking, the queries regarding the DDR3 controller IP as below:

Question:The DDR3 controller IP by default used the soft memory controller. Is there any rule/ compulsion to use a soft memory controller while using NIOS (SOFT PROCESSOR)?

Answer: For rule to use the soft memory controller, you may need to refer to the document as link below:

https://www.intel.com/content/dam/altera-www/global/zh_CN/pdfs/literature/hb/external-memory/emi_intro_about.pdf

Question: The AFI clock output generated by the IP, should it be connected as input clock to the custom design or any PLL clock output with same clock can do?

Answer: AFI_clk output from DDR IP can be used to connect to custom design logic that interact with DDR controller IP

so that both custom design logic and DDR IP is synchronizing (due to using same clock source). It can be said as the AFI_clk output is used as the reference clock for custom design logic.

Thanks