litex/migen/uio/ioo.py

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from migen.fhdl.structure import *
from migen.flow.actor import *
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from migen.actorlib.sim import TokenExchanger, Token
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from migen.bus import wishbone
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from migen.bus.transactions import *
from migen.uio.trampoline import Trampoline
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class UnifiedIOObject(Actor):
def __init__(self, dataflow=None, buses={}):
if dataflow is not None:
super().__init__(*dataflow)
self.buses = buses
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(_WAIT_COMPLETE, _WAIT_POLL) = range(2)
class UnifiedIOSimulation(UnifiedIOObject):
def __init__(self, generator, dataflow=None, buses={}):
self.generator = Trampoline(generator)
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super().__init__(dataflow, buses)
self.callers = []
self.busname_to_caller_id = {}
if dataflow is not None:
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self.callers.append(TokenExchanger(self.dispatch_g(0), self))
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for k, v in self.buses.items():
caller_id = len(self.callers)
self.busname_to_caller_id[k] = caller_id
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g = self.dispatch_g(caller_id)
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if isinstance(v, wishbone.Interface):
caller = wishbone.Initiator(g, v)
else:
raise NotImplementedError
self.callers.append(caller)
self.dispatch_state = _WAIT_COMPLETE
self.dispatch_caller = 0
self.pending_transaction = None
def identify_transaction(self, t):
if isinstance(t, Token):
return 0
elif isinstance(t, TRead) or isinstance(t, TWrite):
if t.busname is None:
if len(self.busname_to_caller_id) != 1:
raise TypeError
else:
return list(self.busname_to_caller_id.values())[0]
else:
return self.busname_to_caller_id[t.busname]
else:
raise TypeError
def dispatch_g(self, caller_id):
while True:
if self.dispatch_state == _WAIT_COMPLETE and self.dispatch_caller == caller_id:
transaction = next(self.generator)
tr_cid = self.identify_transaction(transaction)
self.dispatch_caller = tr_cid
if tr_cid == caller_id:
yield transaction
else:
self.pending_transaction = transaction
self.dispatch_state = _WAIT_POLL
yield None
elif self.dispatch_state == _WAIT_POLL and self.dispatch_caller == caller_id:
self.dispatch_state = _WAIT_COMPLETE
yield self.pending_transaction
else:
yield None
def get_fragment(self):
return sum([c.get_fragment() for c in self.callers], Fragment())