add board tuning parameters

litedram/common.py

@@ -10,7 +10,8 @@ class PhySettings:
                  nphases,
                  rdphase, wrphase,
                  rdcmdphase, wrcmdphase,
-                 cl, read_latency, write_latency, cwl=0):
+                 cl, read_latency, write_latency, cwl=0,
+                 rtt_nom='40ohm', drive_strength='40ohm', dynamic_odt='60ohm'):
         self.memtype = memtype
         self.dfi_databits = dfi_databits
 
@@ -25,6 +26,11 @@ class PhySettings:
         self.write_latency = write_latency
         self.cwl = cwl
 
+        # board tuning parameters
+        self.rtt_nom = rtt_nom
+        self.drive_strength = drive_strength
+        self.dynamic_odt = dynamic_odt
+
 
 class GeomSettings:
     def __init__(self, bankbits, rowbits, colbits):

litedram/sdram_init.py

@@ -24,10 +24,8 @@ static void command_p{n}(int cmd)
     r += """
 #define sdram_dfii_pird_address_write(X) sdram_dfii_pi{rdphase}_address_write(X)
 #define sdram_dfii_piwr_address_write(X) sdram_dfii_pi{wrphase}_address_write(X)
-
 #define sdram_dfii_pird_baddress_write(X) sdram_dfii_pi{rdphase}_baddress_write(X)
 #define sdram_dfii_piwr_baddress_write(X) sdram_dfii_pi{wrphase}_baddress_write(X)
-
 #define command_prd(X) command_p{rdphase}(X)
 #define command_pwr(X) command_p{wrphase}(X)
 """.format(rdphase=str(sdram_phy_settings.rdphase), wrphase=str(sdram_phy_settings.wrphase))
@@ -190,9 +188,26 @@ const unsigned int sdram_dfii_pix_rddata_addr[{n}] = {{
             mr2 |= rtt_wr << 9
             return mr2
 
-        mr0 = format_mr0(bl, cl, 8, 1)  # wr=8 FIXME: this should be ceiling(tWR/tCK)
-        mr1 = format_mr1(1, 1)  # Output Drive Strength RZQ/7 (34 ohm) / Rtt RZQ/4 (60 ohm)
-        mr2 = format_mr2(sdram_phy_settings.cwl, 2)  # Rtt(WR) RZQ/4
+        z_to_rttnom = {
+            'disabled' : 0,
+            '60ohm'    : 1,
+            '120ohm'   : 2,
+            '40ohm'    : 3,
+            '20ohm'    : 4,
+            '30ohm'    : 5
+        }
+        z_to_output_drive_strength = {
+            '40ohm' : 0,
+            '34ohm' : 1,
+        }
+        z_to_dynamic_odt = {
+            'disabled' : 0,
+            '60ohm'    : 1,
+            '120ohm'   : 2,
+        }
+        mr0 = format_mr0(bl, cl, 14, 1)  # wr=8 FIXME: this should be ceiling(tWR/tCK)
+        mr1 = format_mr1(z_to_output_drive_strength[sdram_phy_settings.drive_strength], z_to_rttnom[sdram_phy_settings.rtt_nom])
+        mr2 = format_mr2(sdram_phy_settings.cwl, z_to_dynamic_odt[sdram_phy_settings.dynamic_odt])
         mr3 = 0
 
         init_sequence = [