litex/migen/bank/eventmanager.py

65 lines
1.9 KiB
Python

from migen.fhdl.structure import *
from migen.fhdl.module import Module
from migen.bank.description import *
from migen.genlib.misc import optree
class _EventSource(HUID):
def __init__(self):
HUID.__init__(self)
self.trigger = Signal()
self.pending = Signal()
class EventSourcePulse(_EventSource):
pass
class EventSourceLevel(_EventSource):
pass
class EventManager(Module, AutoReg):
def __init__(self):
self.irq = Signal()
def do_finalize(self):
sources_u = [v for v in self.__dict__.values() if isinstance(v, _EventSource)]
sources = sorted(sources_u, key=lambda x: x.huid)
n = len(sources)
self.status = RegisterRaw(n)
self.pending = RegisterRaw(n)
self.enable = RegisterFields(*(Field(1, READ_WRITE, READ_ONLY, name="e" + str(i)) for i in range(n)))
# status
for i, source in enumerate(sources):
if isinstance(source, EventSourcePulse):
self.comb += self.status.w[i].eq(0)
elif isinstance(source, EventSourceLevel):
self.comb += self.status.w[i].eq(source.trigger)
else:
raise TypeError
# pending
for i, source in enumerate(sources):
# W1C
self.sync += If(self.pending.re & self.pending.r[i], source.pending.eq(0))
if isinstance(source, EventSourcePulse):
# set on a positive trigger pulse
self.sync += If(source.trigger, source.pending.eq(1))
elif isinstance(source, EventSourceLevel):
# set on the falling edge of the trigger
old_trigger = Signal()
self.sync += [
old_trigger.eq(source.trigger),
If(~source.trigger & old_trigger, source.pending.eq(1))
]
else:
raise TypeError
self.comb += self.pending.w[i].eq(source.pending)
# IRQ
irqs = [self.pending.w[i] & field.r for i, field in enumerate(self.enable.fields)]
self.comb += self.irq.eq(optree("|", irqs))
def __setattr__(self, name, value):
if isinstance(value, _EventSource) and self.finalized:
raise FinalizeError
object.__setattr__(self, name, value)