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actorlib: structuring (untested)

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1 parent 1576cb0 commit 7d0e179a035e4f9d8517250d4737d5dce169647b @sbourdeauducq sbourdeauducq committed Jun 20, 2012
Showing with 90 additions and 0 deletions.
  1. +90 −0 migen/actorlib/structuring.py
@@ -0,0 +1,90 @@
+from migen.fhdl.structure import *
+from migen.flow.actor import *
+
+class Cast(CombinatorialActor):
+ def __init__(self, layout_from, layout_to):
+ super().__init__(
+ ("sink", Sink, layout_from),
+ ("source", Source, layout_to))
+
+ def get_process_fragment(self):
+ sigs_from = self.token("sink").flatten()
+ sigs_to = self.token("source").flatten()
+ if sum(len(s) for s in sigs_from) != sum(len(s) for s in sigs_to):
+ raise TypeError
+ return Fragment([
+ Cat(*sigs_to).eq(Cat(*sigs_from))
+ ])
+
+class Chop(Actor):
+ def __init__(self, n, layout_to):
+ self.n = n
+ layout_from = [("chunk{0}".format(i), layout_to)
+ for i in range(self.n)]
+ super().__init__(
+ ("sink", Sink, layout_from),
+ ("source", Source, layout_to))
+
+ def get_fragment(self):
+ muxbits = bits_for(self.n-1)
+ mux = Signal(BV(muxbits))
+ last = Signal()
+ comb = [
+ last.eq(mux == (self.n-1)),
+ self.endpoints["source"].stb.eq(self.endpoints["sink"].stb),
+ self.endpoints["sink"].ack.eq(last & self.endpoints["source"].ack)
+ ]
+ sync = [
+ If(self.endpoints["source"].stb & self.endpoints["source"].ack,
+ If(last,
+ mux.eq(0)
+ ).Else(
+ mux.eq(mux + 1)
+ )
+ )
+ ]
+ cases = [(Constant(i, BV(muxbits)),
+ Cat(*self.token("source").flatten()).eq(*self.token("sink").subrecord("chunk{0}".format(i)).flatten()))
+ for i in range(self.n)]
+ cases[-1][0] = Default()
+ comb.append(Case(mux, *cases))
+ return Fragment(comb, sync)
+
+class Pack(Actor):
+ def __init__(self, layout_from, n):
+ self.n = n
+ layout_to = [("chunk{0}".format(i), layout_from)
+ for i in range(self.n)]
+ super().__init__(
+ ("sink", Sink, layout_from),
+ ("source", Source, layout_to))
+
+ def get_fragment(self):
+ demuxbits = bits_for(self.n-1)
+ demux = Signal(BV(demuxbits))
+
+ load_part = Signal()
+ strobe_all = Signal()
+ cases = [(Constant(i, BV(demuxbits)),
+ Cat(*self.token("source").subrecord("chunk{0}".format(i)).flatten()).eq(*self.token("sink").flatten())
+ for i in range(self.n)]
+ comb = [
+ self.endpoints["sink"].ack.eq(~strobe_all | self.endpoints["source"].ack),
+ self.endpoints["source"].stb.eq(strobe_all),
+ load_part.eq(self.endpoints["sink"].stb & self.endpoints["sink"].ack)
+ ]
+ sync = [
+ If(self.endpoints["source"].ack,
+ strobe_all.eq(0)
+ ),
+ If(load_part,
+ Case(demux, *cases),
+ If(demux == (self.n - 1),
+ demux.eq(0),
+ strobe_all.eq(1)
+ ).Else(
+ demux.eq(demux + 1)
+ )
+ )
+ ]
+ return Fragment(comb, sync)

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