popts->zq_en = 1;
 
        if (ddr_freq < 2350) {
-               popts->ddr_cdr1 = DDR_CDR1_DHC_EN |
-                                 DDR_CDR1_ODT(DDR_CDR_ODT_60ohm);
-               popts->ddr_cdr2 = DDR_CDR2_ODT(DDR_CDR_ODT_60ohm) |
-                                 DDR_CDR2_VREF_RANGE_2;
+               if (pdimm[0].n_ranks == 2 && pdimm[1].n_ranks == 2) {
+                       /* four chip-selects */
+                       popts->ddr_cdr1 = DDR_CDR1_DHC_EN |
+                                         DDR_CDR1_ODT(DDR_CDR_ODT_80ohm);
+                       popts->ddr_cdr2 = DDR_CDR2_ODT(DDR_CDR_ODT_80ohm);
+                       popts->twot_en = 1;     /* enable 2T timing */
+               } else {
+                       popts->ddr_cdr1 = DDR_CDR1_DHC_EN |
+                                         DDR_CDR1_ODT(DDR_CDR_ODT_60ohm);
+                       popts->ddr_cdr2 = DDR_CDR2_ODT(DDR_CDR_ODT_60ohm) |
+                                         DDR_CDR2_VREF_RANGE_2;
+               }
        } else {
                popts->ddr_cdr1 = DDR_CDR1_DHC_EN |
                                  DDR_CDR1_ODT(DDR_CDR_ODT_100ohm);