From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Tue, 31 Dec 2019 09:33:12 +0000 (+0100)
Subject: build/microsemi/libero_soc: update add_period_constraint behavior when clock is alrea... 
X-Git-Tag: 24jan2021_ls180~782
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=9336fe11390eb7fd26245f48a6a5f2937e9824fd;p=litex.git

build/microsemi/libero_soc: update add_period_constraint behavior when clock is already constrainted.
---

diff --git a/litex/build/microsemi/libero_soc.py b/litex/build/microsemi/libero_soc.py
index 7ca51db3..8110034d 100644
--- a/litex/build/microsemi/libero_soc.py
+++ b/litex/build/microsemi/libero_soc.py
@@ -288,7 +288,9 @@ class MicrosemiLiberoSoCPolarfireToolchain:
 
     def add_period_constraint(self, platform, clk, period):
         if clk in self.clocks:
-            raise ValueError("A period constraint already exists")
+            if period != self.clocks[clk]:
+                raise ValueError("Clock already constrained to {:.2f}ns, new constraint to {:.2f}ns"
+                    .format(self.clocks[clk], period))
         self.clocks[clk] = period
 
     def add_false_path_constraint(self, platform, from_, to):