litex/misoclib/com/liteeth/mac/core/padding.py

57 lines
1.6 KiB
Python

from misoclib.com.liteeth.common import *
class LiteEthMACPaddingInserter(Module):
def __init__(self, dw, padding):
self.sink = sink = Sink(eth_phy_description(dw))
self.source = source = Source(eth_phy_description(dw))
# # #
padding_limit = math.ceil(padding/(dw/8))-1
self.submodules.counter = counter = Counter(16, reset=1)
counter_done = Signal()
self.comb += [
counter.reset.eq(sink.stb & sink.sop & sink.ack),
counter.ce.eq(source.stb & source.ack),
counter_done.eq(counter.value >= padding_limit),
]
self.submodules.fsm = fsm = FSM(reset_state="IDLE")
fsm.act("IDLE",
Record.connect(sink, source),
If(source.stb & source.ack,
counter.ce.eq(1),
If(sink.eop,
If(~counter_done,
source.eop.eq(0),
NextState("PADDING")
)
)
)
)
fsm.act("PADDING",
source.stb.eq(1),
source.eop.eq(counter_done),
source.data.eq(0),
If(source.ack,
If(counter_done,
NextState("IDLE")
)
)
)
class LiteEthMACPaddingChecker(Module):
def __init__(self, dw, packet_min_length):
self.sink = sink = Sink(eth_phy_description(dw))
self.source = source = Source(eth_phy_description(dw))
# # #
# XXX see if we should drop the packet when
# payload size < minimum ethernet payload size
self.comb += Record.connect(sink, source)