xilinx/ise: fix add_period_constraint

jordens · jordens · commit f7304a179125 · 2016-04-02T08:59:50.000+02:00
diff --git a/migen/build/xilinx/ise.py b/migen/build/xilinx/ise.py
@@ -201,10 +201,9 @@ def add_period_constraint(self, platform, clk, period):
         platform.add_platform_command(
             """
 NET "{clk}" TNM_NET = "PRD{clk}";
-TIMESPEC "TS{clk}" = PERIOD "PRD{clk}" {period} ns HIGH 50%;
+TIMESPEC "TS{clk}" = PERIOD "PRD{clk}" """ + str(period) + """ ns HIGH 50%;
 """,
             clk=clk,
-            period=str(period),
             )
 
     def add_false_path_constraint(self, platform, from_, to):
