diff --git a/liteeth/common.py b/liteeth/common.py
index 540747f4c..88433e5c1 100644
--- a/liteeth/common.py
+++ b/liteeth/common.py
@@ -93,7 +93,6 @@ def eth_mac_description(dw):
 def eth_arp_description(dw):
 	layout = _layout_from_header(arp_header) + [
 		("data", dw),
-		("last_be", dw//8),
 		("error", dw//8)
 	]
 	return EndpointDescription(layout, packetized=True)
@@ -101,7 +100,6 @@ def eth_arp_description(dw):
 def eth_ipv4_description(dw):
 	layout = _layout_from_header(ipv4_header) + [
 		("data", dw),
-		("last_be", dw//8),
 		("error", dw//8)
 	]
 	return EndpointDescription(layout, packetized=True)
@@ -109,8 +107,56 @@ def eth_ipv4_description(dw):
 def eth_udp_description(dw):
 	layout = _layout_from_header(udp_header) + [
 		("data", dw),
-		("last_be", dw//8),
 		("error", dw//8)
 	]
 	return EndpointDescription(layout, packetized=True)
 
+# Generic modules
+@DecorateModule(InsertReset)
+@DecorateModule(InsertCE)
+class Counter(Module):
+	def __init__(self, signal=None, **kwargs):
+		if signal is None:
+			self.value = Signal(**kwargs)
+		else:
+			self.value = signal
+		self.width = flen(self.value)
+		self.sync += self.value.eq(self.value+1)
+
+@DecorateModule(InsertReset)
+@DecorateModule(InsertCE)
+class Timeout(Module):
+	def __init__(self, length):
+		self.reached = Signal()
+		###
+		value = Signal(max=length)
+		self.sync += value.eq(value+1)
+		self.comb += self.reached.eq(value == length)
+
+class BufferizeEndpoints(ModuleDecorator):
+	def __init__(self, submodule, *args):
+		ModuleDecorator.__init__(self, submodule)
+
+		endpoints = get_endpoints(submodule)
+		sinks = {}
+		sources = {}
+		for name, endpoint in endpoints.items():
+			if name in args or len(args) == 0:
+				if isinstance(endpoint, Sink):
+					sinks.update({name : endpoint})
+				elif isinstance(endpoint, Source):
+					sources.update({name : endpoint})
+
+		# add buffer on sinks
+		for name, sink in sinks.items():
+			buf = Buffer(sink.description)
+			self.submodules += buf
+			setattr(self, name, buf.d)
+			self.comb += Record.connect(buf.q, sink)
+
+		# add buffer on sources
+		for name, source in sources.items():
+			buf = Buffer(source.description)
+			self.submodules += buf
+			self.comb += Record.connect(source, buf.d)
+			setattr(self, name, buf.q)
diff --git a/liteeth/mac/core/depacketizer.py b/liteeth/mac/core/depacketizer.py
new file mode 100644
index 000000000..b0e1a08e7
--- /dev/null
+++ b/liteeth/mac/core/depacketizer.py
@@ -0,0 +1,63 @@
+import math
+
+from liteeth.common import *
+
+def _decode_header(h_dict, h_signal, obj):
+	r = []
+	for k, v in sorted(h_dict.items()):
+		start = v.byte*8+v.offset
+		end = start+v.width
+		r.append(getattr(obj, k).eq(h_signal[start:end]))
+	return r
+
+class LiteEthMACDepacketizer(Module):
+	def __init__(self):
+		self.sink = sink = Sink(eth_mac_description(8))
+		self.source = source = Source(eth_phy_description(8))
+		###
+		shift = Signal()
+		header = Signal(mac_header_length*8)
+		counter = Counter(max=mac_header_length)
+		self.submodules += counter
+
+		fsm = FSM(reset_state="IDLE")
+		self.submodules += fsm
+
+		fsm.act("IDLE",
+			sink.ack.eq(1),
+			counter.reset.eq(1),
+			If(sink.stb,
+				shift.eq(1),
+				NextState("RECEIVE_HEADER")
+			)
+		)
+		fsm.act("RECEIVE_HEADER",
+			sink.ack.eq(1),
+			If(sink.stb,
+				counter.ce.eq(1),
+				shift.eq(1),
+				If(counter.value == mac_header_length-2,
+					NextState("COPY")
+				)
+			)
+		)
+		self.sync += \
+			If(fsm.before_entering("COPY"),
+				source.sop.eq(1)
+			).Elif(source.stb & source.ack,
+				source.sop.eq(0)
+			)
+		self.comb += [
+			source.sop.eq(sop),
+			source.eop.eq(sink.eop),
+			source.data.eq(sink.data),
+			source.error.eq(sink.error),
+			_decode_header(mac_header, header, source)
+		]
+		fsm.act("COPY",
+			sink.ack.eq(source.ack),
+			source.stb.eq(sink.stb),
+			If(source.stb &  source.ack & source.eop,
+				NextState("IDLE")
+			)
+		)
diff --git a/liteeth/mac/core/packetizer.py b/liteeth/mac/core/packetizer.py
new file mode 100644
index 000000000..66600216a
--- /dev/null
+++ b/liteeth/mac/core/packetizer.py
@@ -0,0 +1,73 @@
+from liteeth.common import *
+
+def _encode_header(h_dict, h_signal, obj):
+	r = []
+	for k, v in sorted(h_dict.items()):
+		start = v.word*32+v.offset
+		end = start+v.width
+		r.append(h_signal[start:end].eq(getattr(obj, k)))
+	return r
+
+class LiteEthMACPacketizer(Module):
+	def __init__(self):
+		self.sink = sink = Sink(eth_phy_description(8))
+		self.source = source = Source(eth_mac_description(8))
+		###
+		header = Signal(mac_header_length*8)
+		header_reg = Signal(mac_header_length*8)
+		load = Signal()
+		shift = Signal()
+		counter = Counter(max=mac_header_length)
+		self.submodules += counter
+
+		self.comb += header.eq(_encode_header(mac_header, header, sink))
+		self.sync += [
+			If(load,
+				header_reg.eq(header)
+			).Elif(shift,
+				header_reg.eq(Cat(header_reg[8:], Signal(8)))
+			)
+		]
+
+		fsm = FSM(reset_state="IDLE")
+		self.submodules += fsm
+
+		fsm.act("IDLE",
+			sink.ack.eq(1),
+			If(sink.stb & sink.sop,
+				load.eq(1),
+				sink.ack.eq(0),
+				source.stb.eq(1),
+				source.sop.eq(1),
+				source.eop.eq(0),
+				source.data.eq(header[:8]),
+				If(source.stb & source.ack,
+					NextState("SEND_HEADER"),
+				)
+			)
+		)
+		fsm.act("SEND_HEADER",
+			source.stb.eq(1),
+			source.sop.eq(0),
+			source.eop.eq(sink.eop),
+			source.data.eq(header_reg[8:16]),
+			If(source.stb & source.ack,
+				sink.ack.eq(1),
+				If(counter == mac_header_length-2,
+					NextState("COPY")
+				)
+			)
+		)
+		fsm.act("COPY",
+			source.stb.eq(sink.stb),
+			source.sop.eq(0),
+			source.eop.eq(sink_eop),
+			source.data.eq(sink.data),
+			source.error.eq(sink.error),
+			If(source.stb & source.ack,
+				sink.ack.eq(1),
+				If(source.eop,
+					NextState("IDLE")
+				)
+			)
+		)