Linux hang for SDRAM access

[yourcomrade]

Hi @zangman , thank you for the amazing de10-nano tutorial. Most of the parts of the tutorial I follow work fine except for the FPGA-SDRAM communication part. I have both used the u-boot script in the tutorial and manually changed the register but the HPS still hangs while FPGA tried to access SDRAM. What is your advice to solve this problem?