using a dual rank DDR4 but the IP is single rank: disabling 2nd rank by

setting CS1_n=1, CKE1=0 and ODT1=0

libraries/technology/ddr/tech_ddr_arria10.vhd

@@ -90,6 +90,11 @@ BEGIN
   ctlr_gen_rst <= NOT ctlr_gen_rst_n;
     
   gen_ip_arria10_ddr4_4g_1600 : IF g_tech_ddr.name="DDR4" AND c_gigabytes=4 AND g_tech_ddr.mts=1600 GENERATE
+
+    phy_ou.cs_n(1) <= '1';
+    phy_ou.cke(1)  <= '0';
+    phy_ou.odt(1)  <= '0';
+
     u_ip_arria10_ddr4_4g_1600 : ip_arria10_ddr4_4g_1600
     PORT MAP (
       amm_ready_0         => ctlr_miso.waitrequest_n,                                   --     ctrl_amm_avalon_slave_0.waitrequest_n