diff --git a/litex/build/xilinx/vivado.py b/litex/build/xilinx/vivado.py index 4b9fedfa1..ea5eb0111 100644 --- a/litex/build/xilinx/vivado.py +++ b/litex/build/xilinx/vivado.py @@ -21,7 +21,7 @@ def _format_constraint(c): elif isinstance(c, Misc): return "set_property " + c.misc.replace("=", " ") elif isinstance(c, Inverted): - return "" + return None else: raise ValueError("unknown constraint {}".format(c)) @@ -33,7 +33,8 @@ def _format_xdc(signame, resname, *constraints): fmt_r += "." + resname[2] r = " ## {}\n".format(fmt_r) for c in fmt_c: - r += c + " [get_ports " + signame + "]\n" + if c is not None: + r += c + " [get_ports " + signame + "]\n" return r