flow: hooks

diff --git a/migen/flow/hooks.py b/migen/flow/hooks.py
new file mode 100644 (file)
index 0000000..1afa186
--- /dev/null
+++ b/migen/flow/hooks.py
@@ -0,0 +1,45 @@
+from migen.fhdl.structure import *
+from migen.flow.actor import *
+from migen.sim.generic import PureSimulable
+
+class EndpointHook(PureSimulable):
+       def __init__(self, endpoint):
+               self.endpoint = endpoint
+       
+       def on_ack(self):
+               pass
+       
+       def on_nack(self):
+               pass
+       
+       def on_inactive(self):
+               pass
+       
+       def do_simulation(self, s):
+               if s.rd(self.endpoint.stb):
+                       if s.rd(self.endpoint.ack):
+                               self.on_ack()
+                       else:
+                               self.on_nack()
+               else:
+                       self.on_inactive()
+
+class DFGHook:
+       def __init__(self, dfg, create):
+               assert(not dfg.is_abstract())
+               self.nodepair_to_ep = dict()
+               for u, v, data in dfg.edges_iter(data=True):
+                       if (u, v) in self.nodepair_to_ep:
+                               ep_to_hook = self.nodepair_to_ep[(u, v)]
+                       else:
+                               ep_to_hook = dict()
+                               self.nodepair_to_ep[(u, v)] = ep_to_hook
+                       ep = data["source"]
+                       ep_to_hook[ep] = create(u, ep, v)
+       
+       def get_fragment(self):
+               frag = Fragment()
+               for v1 in self.nodepair_to_ep.values():
+                       for v2 in v1.values():
+                               frag += v2.get_fragment()
+               return frag