litex/migen/genlib/ioo.py

77 lines
2.3 KiB
Python

from migen.fhdl.structure import *
from migen.fhdl.specials import Memory
from migen.flow.actor import *
from migen.flow.transactions import *
from migen.actorlib.sim import TokenExchanger
from migen.bus import wishbone, memory
from migen.bus.transactions import *
class UnifiedIOObject(Module):
def __init__(self, dataflow=None, buses={}):
if dataflow is not None:
self.busy = Signal()
for name, cl, layout in dataflow:
setattr(self, name, cl(layout))
self.buses = buses
self.specials += set(v for v in self.buses.values() if isinstance(v, Memory))
(_WAIT_COMPLETE, _WAIT_POLL) = range(2)
class UnifiedIOSimulation(UnifiedIOObject):
def __init__(self, generator, dataflow=None, buses={}):
self.generator = generator
UnifiedIOObject.__init__(self, dataflow, buses)
callers = []
self.busname_to_caller_id = {}
if dataflow is not None:
callers.append(TokenExchanger(self.dispatch_g(0), self))
for k, v in self.buses.items():
caller_id = len(callers)
self.busname_to_caller_id[k] = caller_id
g = self.dispatch_g(caller_id)
if isinstance(v, wishbone.Interface):
caller = wishbone.Initiator(g, v)
elif isinstance(v, Memory):
caller = memory.Initiator(g, v)
else:
raise NotImplementedError
callers.append(caller)
self.submodules += callers
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