liteeth/liteeth/phy/rmii.py
2017-07-01 11:22:26 +02:00

127 lines
4.1 KiB
Python

from liteeth.common import *
from litex.gen.genlib.cdc import MultiReg
from litex.gen.genlib.misc import WaitTimer
from litex.gen.genlib.io import DDROutput
from litex.gen.genlib.resetsync import AsyncResetSynchronizer
from liteeth.phy.common import *
def converter_description(dw):
payload_layout = [("data", dw)]
return EndpointDescription(payload_layout)
class LiteEthPHYRMIITX(Module):
def __init__(self, pads):
self.sink = sink = stream.Endpoint(eth_phy_description(8))
# # #
converter = stream.StrideConverter(converter_description(8),
converter_description(2))
self.submodules += converter
self.comb += [
converter.sink.valid.eq(sink.valid),
converter.sink.data.eq(sink.data),
sink.ready.eq(converter.sink.ready),
converter.source.ready.eq(1)
]
pads.tx_en.reset_less = True
pads.tx_data.reset_less = True
self.sync += [
pads.tx_en.eq(converter.source.valid),
pads.tx_data.eq(converter.source.data)
]
class LiteEthPHYRMIIRX(Module):
def __init__(self, pads):
self.source = source = stream.Endpoint(eth_phy_description(8))
# # #
converter = stream.StrideConverter(converter_description(2),
converter_description(8))
converter = ResetInserter()(converter)
self.submodules += converter
converter_sink_valid = Signal()
converter_sink_data = Signal(2)
self.specials += [
MultiReg(converter_sink_valid, converter.sink.valid, n=2),
MultiReg(converter_sink_data, converter.sink.data, n=2)
]
crs_dv = Signal()
crs_dv_d = Signal()
rx_data = Signal(2)
self.sync += [
crs_dv.eq(pads.crs_dv),
crs_dv_d.eq(crs_dv),
rx_data.eq(pads.rx_data)
]
self.submodules.fsm = fsm = FSM(reset_state="IDLE")
fsm.act("IDLE",
If(crs_dv & (rx_data != 0b00),
converter_sink_valid.eq(1),
converter_sink_data.eq(rx_data),
NextState("RECEIVE")
).Else(
converter.reset.eq(1)
)
)
fsm.act("RECEIVE",
converter_sink_valid.eq(1),
converter_sink_data.eq(rx_data),
# end of frame when 2 consecutives 0 on crs_dv
If(~(crs_dv | crs_dv_d),
converter.sink.last.eq(1),
NextState("IDLE")
)
)
self.comb += converter.source.connect(source)
class LiteEthPHYRMIICRG(Module, AutoCSR):
def __init__(self, clock_pads, pads, with_hw_init_reset):
self._reset = CSRStorage()
# # #
self.clock_domains.cd_eth_rx = ClockDomain()
self.clock_domains.cd_eth_tx = ClockDomain()
self.comb += [
self.cd_eth_rx.clk.eq(ClockSignal("eth")),
self.cd_eth_tx.clk.eq(ClockSignal("eth"))
]
self.specials += DDROutput(0, 1, clock_pads.ref_clk, ClockSignal("eth_tx"))
reset = Signal()
if with_hw_init_reset:
self.submodules.hw_reset = LiteEthPHYHWReset()
self.comb += reset.eq(self._reset.storage | self.hw_reset.reset)
else:
self.comb += reset.eq(self._reset.storage)
self.comb += pads.rst_n.eq(~reset)
self.specials += [
AsyncResetSynchronizer(self.cd_eth_tx, reset),
AsyncResetSynchronizer(self.cd_eth_rx, reset),
]
class LiteEthPHYRMII(Module, AutoCSR):
def __init__(self, clock_pads, pads, with_hw_init_reset=True):
self.dw = 8
self.submodules.crg = LiteEthPHYRMIICRG(clock_pads, pads, with_hw_init_reset)
self.submodules.tx = ClockDomainsRenamer("eth_tx")(LiteEthPHYRMIITX(pads))
self.submodules.rx = ClockDomainsRenamer("eth_rx")(LiteEthPHYRMIIRX(pads))
self.sink, self.source = self.tx.sink, self.rx.source
if hasattr(pads, "mdc"):
self.submodules.mdio = LiteEthPHYMDIO(pads)