Rewrite stream resets

cocotbext/axi/stream.py

@@ -29,6 +29,8 @@ import cocotb
 from cocotb.triggers import RisingEdge, Event, First, Timer
 from cocotb.bus import Bus
 
+from .reset import Reset
+
 
 class StreamTransaction:
 
@@ -48,7 +50,7 @@ class StreamTransaction:
         return f"{type(self).__name__}({', '.join(f'{s}={int(getattr(self, s))}' for s in self._signals)})"
 
 
-class StreamBase:
+class StreamBase(Reset):
 
     _signals = ["data", "valid", "ready"]
     _optional_signals = []
@@ -73,6 +75,8 @@ class StreamBase:
 
         super().__init__(*args, **kwargs)
 
+        self.active = False
+
         self.queue = deque()
         self.queue_sync = Event()
 
@@ -98,6 +102,10 @@ class StreamBase:
                     v.binstr = 'x'*len(v)
                     getattr(self.bus, sig).setimmediatevalue(v)
 
+        self._run_cr = None
+
+        self._init_reset(reset)
+
     def count(self):
         return len(self.queue)
 
@@ -107,6 +115,22 @@ class StreamBase:
     def clear(self):
         self.queue.clear()
 
+    def _handle_reset(self, state):
+        if state:
+            self.log.info("Reset asserted")
+            if self._run_cr is not None:
+                self._run_cr.kill()
+                self._run_cr = None
+        else:
+            self.log.info("Reset de-asserted")
+            if self._run_cr is None:
+                self._run_cr = cocotb.fork(self._run())
+
+        self.active = False
+
+    async def _run(self):
+        raise NotImplementedError()
+
 
 class StreamPause:
     def __init__(self, *args, **kwargs):
@@ -142,13 +166,6 @@ class StreamSource(StreamBase, StreamPause):
     _valid_init = 0
     _ready_init = None
 
-    def __init__(self, entity, name, clock, reset=None, *args, **kwargs):
-        super().__init__(entity, name, clock, reset, *args, **kwargs)
-
-        self.active = False
-
-        cocotb.fork(self._run())
-
     async def send(self, obj):
         self.send_nowait(obj)
 
@@ -162,6 +179,12 @@ class StreamSource(StreamBase, StreamPause):
         while not self.idle():
             await RisingEdge(self.clock)
 
+    def _handle_reset(self, state):
+        super()._handle_reset(state)
+
+        if self.valid is not None:
+            self.valid <= 0
+
     async def _run(self):
         while True:
             await RisingEdge(self.clock)
@@ -170,13 +193,6 @@ class StreamSource(StreamBase, StreamPause):
             ready_sample = self.ready is None or self.ready.value
             valid_sample = self.valid is None or self.valid.value
 
-            if self.reset is not None and self.reset.value:
-                self.clear()
-                if self.valid is not None:
-                    self.valid <= 0
-                self.active = False
-                continue
-
             if (ready_sample and valid_sample) or (not valid_sample):
                 if self.queue and not self.pause:
                     self.bus.drive(self.queue.popleft())
@@ -196,11 +212,6 @@ class StreamMonitor(StreamBase):
     _valid_init = None
     _ready_init = None
 
-    def __init__(self, entity, name, clock, reset=None, *args, **kwargs):
-        super().__init__(entity, name, clock, reset, *args, **kwargs)
-
-        cocotb.fork(self._run())
-
     async def recv(self):
         while self.empty():
             self.queue_sync.clear()
@@ -229,10 +240,6 @@ class StreamMonitor(StreamBase):
             ready_sample = self.ready is None or self.ready.value
             valid_sample = self.valid is None or self.valid.value
 
-            if self.reset is not None and self.reset.value:
-                self.clear()
-                continue
-
             if ready_sample and valid_sample:
                 obj = self._transaction_obj()
                 self.bus.sample(obj)
@@ -258,6 +265,12 @@ class StreamSink(StreamMonitor, StreamPause):
         else:
             return False
 
+    def _handle_reset(self, state):
+        super()._handle_reset(state)
+
+        if self.ready is not None:
+            self.ready <= 0
+
     async def _run(self):
         while True:
             await RisingEdge(self.clock)
@@ -266,12 +279,6 @@ class StreamSink(StreamMonitor, StreamPause):
             ready_sample = self.ready is None or self.ready.value
             valid_sample = self.valid is None or self.valid.value
 
-            if self.reset is not None and self.reset.value:
-                self.clear()
-                if self.ready is not None:
-                    self.ready <= 0
-                continue
-
             if ready_sample and valid_sample:
                 obj = self._transaction_obj()
                 self.bus.sample(obj)