vendor.xilinx_{7series,spartan6}: emit IBUF/OBUF explicitly.

Do this to make sure all buffers, tristate/differential or not, are
instantiated the exact same way, and are subject to the same set of
toolchain bugs, if any.

diff --git a/nmigen/vendor/xilinx_7series.py b/nmigen/vendor/xilinx_7series.py
index c73c87e0aed276edecc720f9d0c54d172219187a..0235896b74e2ff3bf4aa9857d3b09c93e773ef7d 100644 (file)
--- a/nmigen/vendor/xilinx_7series.py
+++ b/nmigen/vendor/xilinx_7series.py
@@ -234,7 +234,11 @@ class Xilinx7SeriesPlatform(TemplatedPlatform):
                             valid_xdrs=(0, 1, 2), valid_attrs=True)
         m = Module()
         i, o, t = self._get_xdr_buffer(m, pin, i_invert=True if invert else None)
-        m.d.comb += i.eq(port)
+        for bit in range(len(port)):
+            m.submodules += Instance("IBUF",
+                i_I=port[bit],
+                o_O=i[bit]
+            )
         return m
 
     def get_output(self, pin, port, attrs, invert):
@@ -242,7 +246,11 @@ class Xilinx7SeriesPlatform(TemplatedPlatform):
                             valid_xdrs=(0, 1, 2), valid_attrs=True)
         m = Module()
         i, o, t = self._get_xdr_buffer(m, pin, o_invert=True if invert else None)
-        m.d.comb += port.eq(o)
+        for bit in range(len(port)):
+            m.submodules += Instance("OBUF",
+                i_I=o[bit],
+                o_O=port[bit]
+            )
         return m
 
     def get_tristate(self, pin, port, attrs, invert):

diff --git a/nmigen/vendor/xilinx_spartan6.py b/nmigen/vendor/xilinx_spartan6.py
index 7dae41028d8d45711aebfb713013827bbce384fb..8158488cc4fa09ddcf9849e52f494f323a230917 100644 (file)
--- a/nmigen/vendor/xilinx_spartan6.py
+++ b/nmigen/vendor/xilinx_spartan6.py
@@ -249,7 +249,11 @@ class XilinxSpartan6Platform(TemplatedPlatform):
                             valid_xdrs=(0, 1, 2), valid_attrs=True)
         m = Module()
         i, o, t = self._get_xdr_buffer(m, pin, i_invert=True if invert else None)
-        m.d.comb += i.eq(port)
+        for bit in range(len(port)):
+            m.submodules += Instance("IBUF",
+                i_I=port[bit],
+                o_O=i[bit]
+            )
         return m
 
     def get_output(self, pin, port, attrs, invert):
@@ -257,7 +261,11 @@ class XilinxSpartan6Platform(TemplatedPlatform):
                             valid_xdrs=(0, 1, 2), valid_attrs=True)
         m = Module()
         i, o, t = self._get_xdr_buffer(m, pin, o_invert=True if invert else None)
-        m.d.comb += port.eq(o)
+        for bit in range(len(port)):
+            m.submodules += Instance("OBUF",
+                i_I=o[bit],
+                o_O=port[bit]
+            )
         return m
 
     def get_tristate(self, pin, port, attrs, invert):