litex/liteeth/core/etherbone/packet.py

from liteeth.common import *
from liteeth.generic.depacketizer import LiteEthDepacketizer
from liteeth.generic.packetizer import LiteEthPacketizer

class LiteEthEtherbonePacketPacketizer(LiteEthPacketizer):
	def __init__(self):
		LiteEthPacketizer.__init__(self,
			eth_etherbone_packet_description(32),
			eth_udp_user_description(32),
			etherbone_packet_header,
			etherbone_packet_header_len)

class LiteEthEtherbonePacketTX(Module):
	def __init__(self, udp_port):
		self.sink = sink = Sink(eth_etherbone_packet_user_description(32))
		self.source = source = Source(eth_udp_user_description(32))
		###
		self.submodules.packetizer = packetizer = LiteEthEtherbonePacketPacketizer()
		self.comb += [
			packetizer.sink.stb.eq(sink.stb),
			packetizer.sink.sop.eq(sink.sop),
			packetizer.sink.eop.eq(sink.eop),
			sink.ack.eq(packetizer.sink.ack),

			packetizer.sink.magic.eq(etherbone_magic),
			packetizer.sink.port_size.eq(32//8),
			packetizer.sink.addr_size.eq(32//8),
			packetizer.sink.pf.eq(sink.pf),
			packetizer.sink.pr.eq(sink.pr),
			packetizer.sink.nr.eq(sink.nr),
			packetizer.sink.version.eq(etherbone_version),

			packetizer.sink.data.eq(sink.data)
		]
		self.submodules.fsm = fsm = FSM(reset_state="IDLE")
		fsm.act("IDLE",
			packetizer.source.ack.eq(1),
			If(packetizer.source.stb & packetizer.source.sop,
				packetizer.source.ack.eq(0),
				NextState("SEND")
			)
		)
		fsm.act("SEND",
			Record.connect(packetizer.source, source),
			source.src_port.eq(udp_port),
			source.dst_port.eq(udp_port),
			source.ip_address.eq(sink.ip_address),
			source.length.eq(sink.length + etherbone_packet_header_len),
			If(source.stb & source.eop & source.ack,
				NextState("IDLE")
			)
		)

class LiteEthEtherbonePacketDepacketizer(LiteEthDepacketizer):
	def __init__(self):
		LiteEthDepacketizer.__init__(self,
			eth_udp_user_description(32),
			eth_etherbone_packet_description(32),
			etherbone_packet_header,
			etherbone_packet_header_len)

class LiteEthEtherbonePacketRX(Module):
	def __init__(self):
		self.sink = sink = Sink(eth_udp_user_description(32))
		self.source = source = Source(eth_etherbone_packet_user_description(32))
		###
		self.submodules.depacketizer = depacketizer = LiteEthEtherbonePacketDepacketizer()
		self.comb += Record.connect(sink, depacketizer.sink)

		self.submodules.fsm = fsm = FSM(reset_state="IDLE")
		fsm.act("IDLE",
			depacketizer.source.ack.eq(1),
			If(depacketizer.source.stb & depacketizer.source.sop,
				depacketizer.source.ack.eq(0),
				NextState("CHECK")
			)
		)
		valid = Signal()
		self.sync += valid.eq(
			depacketizer.source.stb &
			(depacketizer.source.magic == etherbone_magic)
		)
		fsm.act("CHECK",
			If(valid,
				NextState("PRESENT")
			).Else(
				NextState("DROP")
			)
		)
		self.comb += [
			source.sop.eq(depacketizer.source.sop),
			source.eop.eq(depacketizer.source.eop),

			source.pf.eq(depacketizer.source.pf),
			source.pr.eq(depacketizer.source.pr),
			source.nr.eq(depacketizer.source.nr),

			source.data.eq(depacketizer.source.data),

			source.src_port.eq(sink.src_port),
			source.dst_port.eq(sink.dst_port),
			source.ip_address.eq(sink.ip_address),
			source.length.eq(sink.length - etherbone_packet_header_len)
		]
		fsm.act("PRESENT",
			source.stb.eq(depacketizer.source.stb),
			depacketizer.source.ack.eq(source.ack),
			If(source.stb & source.eop & source.ack,
				NextState("IDLE")
			)
		)
		fsm.act("DROP",
			depacketizer.source.ack.eq(1),
			If(depacketizer.source.stb & depacketizer.source.eop & depacketizer.source.ack,
				NextState("IDLE")
			)
		)

class LiteEthEtherbonePacket(Module):
	def __init__(self, udp, udp_port):
		self.submodules.tx = tx = LiteEthEtherbonePacketTX(udp_port)
		self.submodules.rx = rx = LiteEthEtherbonePacketRX()
		udp_port = udp.crossbar.get_port(udp_port, dw=32)
		self.comb += [
			Record.connect(tx.source, udp_port.sink),
			Record.connect(udp_port.source, rx.sink)
		]
		self.sink, self.source = self.tx.sink, self.rx.source