genlib/cdc: remove AsyncResetSynchronizer on gearbox

enjoy-digital · enjoy-digital · commit 2274a75b7104 · 2017-11-10T10:31:21.000+01:00
Since clocks are running at a different frequency, AsyncResetSynchronizers were delaying reset by a different amount of time on each clockdomain that can cause issues on wpointer/rpointer init.
diff --git a/migen/genlib/cdc.py b/migen/genlib/cdc.py
@@ -211,17 +211,15 @@ def __init__(self, iwidth, idomain, owidth, odomain):
 
         # # #
 
-        reset = Signal()
+        rst = Signal()
         cd_write = ClockDomain()
         cd_read = ClockDomain()
         self.comb += [
+            rst.eq(ResetSignal(idomain) | ResetSignal(odomain)),
             cd_write.clk.eq(ClockSignal(idomain)),
             cd_read.clk.eq(ClockSignal(odomain)),
-            reset.eq(ResetSignal(idomain) | ResetSignal(odomain))
-        ]
-        self.specials += [
-            AsyncResetSynchronizer(cd_write, reset),
-            AsyncResetSynchronizer(cd_read, reset)
+            cd_write.rst.eq(rst),
+            cd_read.rst.eq(rst)
         ]
         self.clock_domains += cd_write, cd_read
 
