From e6bfad498df3f73b7c4448d148f77dd64341e806 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sebastien@milkymist.org>
Date: Sun, 15 Jan 2012 22:08:33 +0100
Subject: [PATCH] actorlib/control: 'for' generator

---
 examples/dataflow_dma.py  | 15 +++++--
 migen/actorlib/control.py | 94 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+), 4 deletions(-)
 create mode 100644 migen/actorlib/control.py

diff --git a/examples/dataflow_dma.py b/examples/dataflow_dma.py
index 267176916..5e6649ada 100644
--- a/examples/dataflow_dma.py
+++ b/examples/dataflow_dma.py
@@ -1,10 +1,9 @@
-import sys
 import networkx as nx
 
 from migen.fhdl import verilog
 from migen.flow.ala import *
 from migen.flow.network import *
-from migen.actorlib import dma_wishbone
+from migen.actorlib import dma_wishbone, control
 
 L = [
 	("x", BV(10), 8),
@@ -15,6 +14,14 @@ L = [
 	])
 ]
 
+adrgen = control.For(10)
 reader = dma_wishbone.Reader(L)
-frag = reader.get_fragment()
-print(verilog.convert(frag, ios=set(reader.bus.signals())))
+
+g = nx.MultiDiGraph()
+add_connection(g, adrgen, reader)
+comp = CompositeActor(g)
+
+frag = comp.get_fragment()
+ios = set(reader.bus.signals())
+ios.add(comp.busy)
+print(verilog.convert(frag, ios=ios))
diff --git a/migen/actorlib/control.py b/migen/actorlib/control.py
new file mode 100644
index 000000000..9819c5dfe
--- /dev/null
+++ b/migen/actorlib/control.py
@@ -0,0 +1,94 @@
+from operator import mul
+from functools import reduce
+
+from migen.fhdl.structure import *
+from migen.corelogic.record import *
+from migen.corelogic.fsm import *
+from migen.flow.actor import *
+
+# Generates integers from start to maximum-1
+class For(Actor):
+	def __init__(self, *maxima, start=False, step=False):
+		self.dimensions = len(maxima)
+		self.start = start
+		self.step = step
+		params = ["end"]
+		if start: params.append("start")
+		if step: params.append("step")
+		self.d_bv = [BV(bits_for(dimension)) for dimension in maxima]
+		l_sink = [("d{0}".format(n), [(p, bv) for p in params])
+			for n, bv in zip(range(len(self.d_bv)), self.d_bv)]
+		l_source = [("d{0}".format(n), bv)
+			for n, bv in zip(range(len(self.d_bv)), self.d_bv)]
+		Actor.__init__(self, SchedulingModel(SchedulingModel.DYNAMIC),
+			("sink", Sink, l_sink),
+			("source", Source, l_source))
+	
+	def get_fragment(self):
+		load = Signal()
+		ce = Signal()
+		last = Signal()
+		
+		counters_v = [Signal(bv, variable=True) for bv in self.d_bv]
+		counters = [getattr(self.token("source"), "d{0}".format(n))
+			for n in range(self.dimensions)]
+		
+		params = [getattr(self.token("sink"), "d{0}".format(n))
+			for n in range(self.dimensions)]
+		if self.start:
+			starts = [p.start for p in params]
+			start_rs = [Signal(s.bv, variable=True) for s in starts]
+		else:
+			start_rs = [Constant(0, bv) for bv in self.d_bv]
+		if self.step:
+			steps = [p.step for p in params]
+			step_rs = [Signal(s.bv, variable=True) for s in steps]
+		else:
+			step_rs = [Constant(1, bv) for bv in self.d_bv]
+		ends = [p.end for p in params]
+		end_rs = [Signal(s.bv, variable=True) for s in ends]
+		
+		lasts = Signal(BV(self.dimensions))
+		
+		on_ce = [
+			If(lasts[n],
+				counter.eq(start)
+			).Else(
+				counter.eq(counter + step)
+			)
+			for n, counter, start, step
+			  in zip(range(self.dimensions), counters_v, start_rs, step_rs)
+		]
+		lasts_gen = [
+			lasts[n].eq(counter + step >= end if self.step else counter + step == end)
+			for n, counter, step, end
+			  in zip(range(self.dimensions), counters_v, step_rs, end_rs)
+		]
+		sync = [
+			If(load,
+				Cat(*start_rs).eq(Cat(*starts)) if self.start else None,
+				Cat(*step_rs).eq(Cat(*steps)) if self.step else None,
+				Cat(*end_rs).eq(Cat(*ends)),
+				Cat(*counters_v).eq(Cat(*start_rs))
+			),
+			If(ce, *on_ce)
+		] + lasts_gen + [
+			Cat(*counters).eq(Cat(*counters_v))
+		]
+		counters_fragment = Fragment(sync=sync)
+		
+		fsm = FSM("IDLE", "ACTIVE")
+		fsm.act(fsm.IDLE,
+			load.eq(1),
+			self.endpoints["sink"].ack.eq(1),
+			If(self.endpoints["sink"].stb, fsm.next_state(fsm.ACTIVE))
+		)
+		fsm.act(fsm.ACTIVE,
+			self.busy.eq(1),
+			self.endpoints["source"].stb.eq(1),
+			If(self.endpoints["source"].ack,
+				ce.eq(1),
+				If(last, fsm.next_state(fsm.IDLE))
+			)
+		)
+		return counters_fragment + fsm.get_fragment()