trace: Add a timeout to end a frame if no new data arrives.

orbcode · Aug 28, 2024 · 7e43c68 · 7e43c68
1 parent 14e974c
commit 7e43c68
Showing 1 changed file with 16 additions and 3 deletions.
diff --git a/orbtrace/trace/tpiu.py b/orbtrace/trace/tpiu.py
@@ -130,29 +130,42 @@ def __init__(self):
         )
 
 class LastFromFirst(Module):
-    def __init__(self):
+    def __init__(self, timeout = 7500000):
         self.sink = sink = Endpoint([('data', 8)])
         self.source = source = Endpoint([('data', 8)])
 
         data = Signal(8)
         first = Signal()
         valid = Signal()
+        timeout_flag = Signal()
+        timeout_cnt = Signal(max = timeout + 1)
 
         self.comb += [
+            timeout_flag.eq(timeout_cnt == 0),
+
             sink.ready.eq(~valid | (source.ready & source.valid)),
 
             source.data.eq(data),
             source.first.eq(first),
-            source.last.eq(sink.first),
-            source.valid.eq(valid & sink.valid),
+            source.last.eq((sink.valid & sink.first) | timeout_flag),
+            source.valid.eq(valid & (sink.valid | timeout_flag)),
         ]
 
         self.sync += [
+            If(source.ready & source.valid,
+                valid.eq(0),
+            ),
             If(sink.ready & sink.valid,
                 data.eq(sink.data),
                 first.eq(sink.first),
                 valid.eq(1),
             ),
+            If(timeout_cnt,
+                timeout_cnt.eq(timeout_cnt - 1),
+            ),
+            If(sink.valid,
+                timeout_cnt.eq(timeout),
+            ),
         ]
 
 class TPIUDemux(Module):