back.pysim: undriven sync signals should return to previous value.

diff --git a/nmigen/back/pysim.py b/nmigen/back/pysim.py
index ba4f0bcd7d9498c8be1b9cf033de913e7c6f57bc..ca01431ea98ff4d8892a54ceb5a6be012148b9b3 100644 (file)
--- a/nmigen/back/pysim.py
+++ b/nmigen/back/pysim.py
@@ -345,6 +345,8 @@ class Simulator:
             statements = []
             for signal in fragment.iter_comb():
                 statements.append(signal.eq(signal.reset))
+            for domain, signal in fragment.iter_sync():
+                statements.append(signal.eq(signal))
             statements += fragment.statements
 
             def add_funclet(signal, funclet):