Tang mega138k

litex/build/gowin/common.py

@@ -96,6 +96,25 @@ class GowinDifferentialOutput:
     def lower(dr):
         return GowinDifferentialOutputImpl(dr.i, dr.o_p, dr.o_n)
 
+# Gowin Tristate -----------------------------------------------------------------------------------
+
+class GowinTristateImpl(Module):
+    def __init__(self, io, o, oe, i):
+        nbits, _ = value_bits_sign(io)
+        for bit in range(nbits):
+            self.specials += Instance("IOBUF",
+                io_IO = io[bit] if nbits > 1 else io,
+                o_O   = i[bit]  if nbits > 1 else i,
+                i_I   = o[bit]  if nbits > 1 else o,
+                i_OEN = ~oe,
+            )
+
+class GowinTristate:
+    @staticmethod
+    def lower(dr):
+        print(dr)
+        return GowinTristateImpl(dr.target, dr.o, dr.oe, dr.i)
+
 # Gowin Special Overrides --------------------------------------------------------------------------
 
 gowin_special_overrides = {
@@ -104,4 +123,5 @@ def lower(dr):
     DDROutput:              GowinDDROutput,
     DifferentialInput:      GowinDifferentialInput,
     DifferentialOutput:     GowinDifferentialOutput,
+    Tristate:               GowinTristate,
 }

litex/build/gowin/gowin.py

@@ -69,15 +69,41 @@ def build_io_constraints(self):
             else:
                 flat_sc.append((name, pins[0], other))
 
+        def _search_pin_entry(pin_lst, pin_name):
+            for name, pin, other in pin_lst:
+                if pin_name == name:
+                    return (name, pin, other)
+            return (None, None, None)
+
         for name, pin, other in flat_sc:
             if pin != "X":
+                t_name = name.split('[') # avoid index pins
+                tmp_name = t_name[0]
+                if tmp_name[-2:] == "_p":
+                    pn = tmp_name[:-2] + "_n"
+                    if len(t_name) > 1:
+                        pn += '[' + t_name[1]
+                    (_, n_pin, _) = _search_pin_entry(flat_sc, pn)
+                    if n_pin is not None:
+                        pin = f"{pin},{n_pin}"
+                elif tmp_name[-2:] == "_n":
+                    pp = tmp_name[:-2] + "_p"
+                    if len(t_name) > 1:
+                        pp += '[' + t_name[1]
+                    (p_name, _, _) = _search_pin_entry(flat_sc, pp)
+                    if p_name is not None:
+                        continue
                 cst.append(f"IO_LOC \"{name}\" {pin};")
 
+            other_cst = []
             for c in other:
                 if isinstance(c, IOStandard):
-                    cst.append(f"IO_PORT \"{name}\" IO_TYPE={c.name};")
+                    other_cst.append(f"IO_TYPE={c.name}")
                 elif isinstance(c, Misc):
-                    cst.append(f"IO_PORT \"{name}\" {c.misc};")
+                    other_cst.append(f"{c.misc}")
+            if len(other_cst):
+                t = " ".join(other_cst)
+                cst.append(f"IO_PORT \"{name}\" {t};")
 
         if self.named_pc:
             cst.extend(self.named_pc)