litex/migen/actorlib/sim.py

70 lines
1.9 KiB
Python

from migen.fhdl.structure import *
from migen.flow.actor import *
from migen.sim.generic import PureSimulable
class Token:
def __init__(self, endpoint, value=None):
self.endpoint = endpoint
self.value = value
# Generators yield None or a tuple of Tokens.
# Tokens for Sink endpoints are pulled and the "value" field filled in.
# Tokens for Source endpoints are pushed according to their "value" field.
#
# NB: the possibility to push several tokens at once is important to interact
# with actors that only accept a group of tokens when all of them are available.
class SimActor(PureSimulable, Actor):
def __init__(self, generator, *endpoint_descriptions, **misc):
self.generator = generator
self.active = set()
self.done = False
super().__init__(*endpoint_descriptions, **misc)
def _process_transactions(self, s):
completed = set()
for token in self.active:
ep = self.endpoints[token.endpoint]
if isinstance(ep, Sink):
if s.rd(ep.ack):
if s.rd(ep.stb):
token.value = s.multiread(ep.token)
completed.add(token)
s.wr(ep.ack, 0)
else:
s.wr(ep.ack, 1)
elif isinstance(ep, Source):
if s.rd(ep.stb):
if s.rd(ep.ack):
completed.add(token)
s.wr(ep.stb, 0)
else:
s.wr(ep.stb, 1)
s.multiwrite(ep.token, token.value)
else:
raise TypeError
self.active -= completed
def _next_transactions(self):
try:
transactions = next(self.generator)
except StopIteration:
self.done = True
transactions = None
if isinstance(transactions, Token):
self.active = {transactions}
elif isinstance(transactions, tuple) \
or isinstance(transactions, list) \
or isinstance(transactions, set):
self.active = set(transactions)
elif transactions is None:
self.active = []
else:
raise TypeError
def do_simulation(self, s):
if not self.done:
if self.active:
self._process_transactions(s)
else:
self._next_transactions()