liteeth/liteeth/phy/rmii.py
2015-11-19 15:42:51 +01:00

108 lines
3.4 KiB
Python

from liteeth.common import *
def converter_description(dw):
payload_layout = [("data", dw)]
return EndpointDescription(payload_layout, packetized=True)
@CEInserter()
class LiteEthPHYRMIITX(Module):
def __init__(self, pads):
self.sink = sink = Sink(eth_phy_description(8))
# # #
converter = Converter(converter_description(8),
converter_description(2))
self.submodules += converter
self.comb += [
converter.sink.stb.eq(sink.stb),
converter.sink.data.eq(sink.data),
sink.ack.eq(converter.sink.ack),
converter.source.ack.eq(1)
]
self.sync += [
pads.tx_en.eq(converter.source.stb),
pads.tx_data.eq(converter.source.data)
]
@CEInserter()
class LiteEthPHYRMIIRX(Module):
def __init__(self, pads):
self.source = source = Source(eth_phy_description(8))
# # #
sop = Signal(reset=1)
sop_set = Signal()
sop_clr = Signal()
self.sync += If(sop_set, sop.eq(1)).Elif(sop_clr, sop.eq(0))
converter = Converter(converter_description(2),
converter_description(8))
converter = ResetInserter()(converter)
self.submodules += converter
self.sync += [
converter.reset.eq(~pads.dv),
converter.sink.stb.eq(1),
converter.sink.data.eq(pads.rx_data)
]
self.sync += [
sop_set.eq(~pads.dv),
sop_clr.eq(pads.dv)
]
self.comb += [
converter.sink.sop.eq(sop),
converter.sink.eop.eq(~pads.dv)
]
self.comb += Record.connect(converter.source, source)
class LiteEthPHYMIICRG(Module, AutoCSR):
def __init__(self, clock_pads, pads, with_hw_init_reset):
self._reset = CSRStorage()
self.ref_clk = Signal()
# # #
# assumming 100MHz clock provided externally
self.sync.eth += self.ref_clk.eq(~self.ref_clk)
self.comb += clock_pads.ref_clk.eq(self.ref_clk)
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.comb += self.cd_eth_tx.clk.eq(ClockSignal("eth"))
if with_hw_init_reset:
reset = Signal()
counter_done = Signal()
self.submodules.counter = counter = Counter(max=512)
self.comb += [
counter_done.eq(counter.value == 256),
counter.ce.eq(~counter_done),
reset.eq(~counter_done | self._reset.storage)
]
else:
reset = 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 = LiteEthPHYMIICRG(clock_pads, pads, with_hw_init_reset)
self.submodules.tx = ClockDomainsRenamer("eth_tx")(LiteEthPHYRMIITX(pads))
self.submodules.rx = ClockDomainsRenamer("eth_tx")(LiteEthPHYRMIIRX(pads))
self.comb += [
self.tx.ce.eq(self.crg.ref_clk == 1),
self.rx.ce.eq(self.crg.ref_clk == 1)
]
self.sink, self.source = self.tx.sink, self.rx.source