From 588f1a259e425c9d2d4e0483ec9c569347dc177a Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sebastien@milkymist.org>
Date: Fri, 6 Jan 2012 17:24:05 +0100
Subject: [PATCH] flow: plumbing

---
 examples/dataflow.py   | 22 ++++++++++++++++++---
 migen/flow/actor.py    |  3 +++
 migen/flow/ala.py      |  2 +-
 migen/flow/plumbing.py | 45 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 68 insertions(+), 4 deletions(-)
 create mode 100644 migen/flow/plumbing.py

diff --git a/examples/dataflow.py b/examples/dataflow.py
index 06c2ab123..57035ce33 100644
--- a/examples/dataflow.py
+++ b/examples/dataflow.py
@@ -1,6 +1,22 @@
 from migen.fhdl import verilog 
 from migen.flow.ala import *
+from migen.flow.plumbing import *
 
-act = Divider(32)
-frag = act.get_control_fragment() + act.get_process_fragment()
-print(verilog.convert(frag))
+act = Adder(32)
+comb = Combinator(act.operands, ["a"], ["b"])
+outbuf = Buffer(act.result.template())
+frag = get_actor_fragments(act, comb, outbuf)
+
+stb_a = comb.sinks[0].stb
+ack_a = comb.sinks[0].ack
+stb_b = comb.sinks[1].stb
+ack_b = comb.sinks[1].ack
+stb_a.name = "stb_a_i"
+ack_a.name = "ack_a_o"
+stb_b.name = "stb_b_i"
+ack_b.name = "stb_b_o"
+a = comb.ins[0].a
+b = comb.ins[1].b
+a.name = "a"
+b.name = "b"
+print(verilog.convert(frag, ios={stb_a, ack_a, stb_b, ack_b, a, b}))
diff --git a/migen/flow/actor.py b/migen/flow/actor.py
index f1b783a67..98e9ba789 100644
--- a/migen/flow/actor.py
+++ b/migen/flow/actor.py
@@ -104,3 +104,6 @@ class Actor:
 	
 	def get_process_fragment(self):
 		raise NotImplementedError("Actor classes must overload get_process_fragment")
+
+def get_actor_fragments(*actors):
+	return sum([a.get_control_fragment() + a.get_process_fragment() for a in actors], Fragment())
diff --git a/migen/flow/ala.py b/migen/flow/ala.py
index b3456eb51..1fc53bb34 100644
--- a/migen/flow/ala.py
+++ b/migen/flow/ala.py
@@ -6,7 +6,7 @@ from migen.corelogic import divider
 class Adder(Actor):
 	def __init__(self, width):
 		self.operands = Record([('a', BV(width)), ('b', BV(width))])
-		self.result = Record(['sum', BV(width+1)])
+		self.result = Record([('sum', BV(width+1))])
 		Actor.__init__(self,
 			SchedulingModel(SchedulingModel.COMBINATORIAL),
 			self.operands, self.result)
diff --git a/migen/flow/plumbing.py b/migen/flow/plumbing.py
new file mode 100644
index 000000000..a3780a159
--- /dev/null
+++ b/migen/flow/plumbing.py
@@ -0,0 +1,45 @@
+from migen.fhdl.structure import *
+from migen.flow.actor import *
+from migen.corelogic.record import *
+from migen.corelogic.misc import optree
+
+class Buffer(Actor):
+	def __init__(self, template):
+		self.d = Record(template)
+		self.q = Record(template)
+		Actor.__init__(self,
+			SchedulingModel(SchedulingModel.PIPELINE, 1),
+			self.d, self.q)
+	
+	def get_process_fragment(self):
+		sigs_d = self.d.flatten()
+		sigs_q = self.q.flatten()
+		sync = [Cat(*sigs_q).eq(Cat(*sigs_d))]
+		return Fragment(sync=sync)
+
+class Combinator(Actor):
+	def __init__(self, destination, *subrecords):
+		self.ins = [destination.subrecord(*subr) for subr in subrecords]
+		Actor.__init__(self,
+			SchedulingModel(SchedulingModel.COMBINATORIAL),
+			self.ins, destination)
+
+	def get_process_fragment(self):
+		return Fragment() # nothing to do
+	
+	def get_control_fragment(self):
+		comb = [self.sources[0].stb.eq(optree('&', [sink.stb for sink in self.sinks]))]
+		comb += [sink.ack.eq(self.sources[0].ack & self.sources[0].stb) for sink in self.sinks]
+		return Fragment(comb)
+
+class Splitter(Actor):
+	def __init__(self, source, *subrecords):
+		self.outs = [source.subrecord(*subr) for subr in subrecords]
+		Actor.__init__(self,
+			SchedulingModel(SchedulingModel.COMBINATORIAL),
+			source, self.outs)
+		
+	def get_process_fragment(self):
+		return Fragment() # nothing to do
+	
+	# TODO def get_control_fragment(self):