Description

Calibration is not completing in behavioral simulation when using VHDL language setting. I see Xs on the DQ signals in ISIM.

How can I fix this?

Solution

1. Open the XPS project, in the System Assembly View right-click on the AXI DDR3 IP and make the IP local.
2. Navigate to the mcb_raw_wrapper.v file in the project pcores directly, similar to the following:
   
   pcores\axi_s6_ddrx_v1_06_a\hdl\verilog\mcb_raw_wrapper.v
   
   Comment out lines 6613 -> 6622:
   
   // DQS PULLDWON
   //generate
   //if(C_MEM_TYPE == "DDR" || C_MEM_TYPE =="MDDR" || (C_MEM_TYPE == "DDR2" && (C_MEM_DDR2_DIFF_DQS_EN == "NO"))) begin: gen_dqs_pullupdn
   //PULLDOWN dqs_pulldown (.O(mcbx_dram_dqs));
   //end else begin: gen_dqs_pullupdn_ds
   //PULLDOWN dqs_pulldown (.O(mcbx_dram_dqs));
   //PULLUP dqs_n_pullup (.O(mcbx_dram_dqs_n));
   
   //end
   //endgenerate
3. Rescan the User repositories in XPS. (Project -> Rescan User Repositories)
   
4. Next, Run Behavioral Simulation, and the tools should pick the updated HDL file.