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wishbone_dma: convert to new endpoint API and fix some bugs
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parent
77b3c8e3bb
commit
85491efc68
2 changed files with 40 additions and 11 deletions
20
examples/dataflow_dma.py
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20
examples/dataflow_dma.py
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@ -0,0 +1,20 @@
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import sys
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import networkx as nx
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from migen.fhdl import verilog
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from migen.flow.ala import *
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from migen.flow.network import *
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from migen.actorlib import dma_wishbone
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L = [
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("x", BV(10), 8),
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("y", BV(10), 8),
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("level2", [
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("a", BV(5), 32),
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("b", BV(5), 16)
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])
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]
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reader = dma_wishbone.Reader(L)
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frag = reader.get_fragment()
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print(verilog.convert(frag, ios=set(reader.bus.signals())))
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@ -6,36 +6,45 @@ from migen.flow.actor import *
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class Reader(Actor):
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def __init__(self, layout):
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self.address = Record([("a", BV(30))])
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self.data = Record(layout)
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self.bus = wishbone.Master()
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Actor.__init__(self,
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SchedulingModel(SchedulingModel.DYNAMIC),
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self.address, self.data)
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("address", Sink, [("a", BV(30))]),
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("data", Source, layout))
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def get_fragment(self):
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components, length = self.data.flatten(align=True, return_offset=True)
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components, length = self.token("data").flatten(align=True, return_offset=True)
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nwords = (length + 31)//32
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# Address generator
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ag_stb = Signal()
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ag_sync = [If(ag_stb, self.bus.adr_o.eq(self.address.a))]
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ag_sync = [If(ag_stb, self.bus.adr_o.eq(self.token("address").a))]
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if nwords > 1:
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ag_inc = Signal()
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sync.append(If(ag_inc, self.bus.adr_o.eq(self.bus.adr_o + 1)))
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ag_sync.append(If(ag_inc, self.bus.adr_o.eq(self.bus.adr_o + 1)))
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address_generator = Fragment(sync=ag_sync)
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# Output buffer
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ob_reg = Signal(BV(length))
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ob_stbs = Signal(BV(nwords))
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ob_sync = [If(ob_stbs[w], ob_reg[32*w:32*(w+1)].eq(self.bus.dat_i))
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for w in range(nwords)]
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ob_sync = []
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top = length
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for w in range(nwords):
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if top >= 32:
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width = 32
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sl = self.bus.dat_i
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else:
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width = top
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sl = self.bus.dat_i[32-top:]
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ob_sync.append(If(ob_stbs[w],
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ob_reg[top-width:top].eq(sl)))
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top -= width
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ob_comb = []
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offset = 0
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for s in components:
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w = s.bv.width
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if isinstance(s, Signal):
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comb.append(s.eq(ob_reg[length-offset-w:length-offset]))
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ob_comb.append(s.eq(ob_reg[length-offset-w:length-offset]))
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offset += w
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output_buffer = Fragment(ob_comb, ob_sync)
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@ -55,12 +64,12 @@ class Reader(Actor):
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if w == nwords - 1:
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next_state = fsm.STROBE
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else:
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state = getattr(fsm, fetch_states[w+1])
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next_state = getattr(fsm, fetch_states[w+1])
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fsm.act(state,
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self.bus.cyc_o.eq(1),
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self.bus.stb_o.eq(1),
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ob_stbs[w].eq(1),
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If(self.bus.ack_i,
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ob_stbs[nwords-w-1].eq(1),
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fsm.next_state(next_state)
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)
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)
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