diff --git a/artiq/gateware/rtio/sed/core.py b/artiq/gateware/rtio/sed/core.py
new file mode 100644
index 000000000..ba87191ad
--- /dev/null
+++ b/artiq/gateware/rtio/sed/core.py
@@ -0,0 +1,81 @@
+from migen import *
+
+from artiq.gateware.rtio import rtlink
+from artiq.gateware.rtio.sed import layouts
+from artiq.gateware.rtio.sed.lane_distributor import *
+from artiq.gateware.rtio.sed.fifos import *
+from artiq.gateware.rtio.sed.gates import *
+from artiq.gateware.rtio.sed.output_driver import *
+
+
+__all__ = ["SED"]
+
+
+class SED(Module):
+    def __init__(self, channels, mode, enable_spread=True, lane_count=8, fifo_depth=128, interface=None):
+        if mode == "sync":
+            lane_dist_cdr = lambda x: x
+            fifos_cdr = lambda x: x
+            gates_cdr = lambda x: x
+            output_driver_cdr = lambda x: x
+        elif mode == "async":
+            lane_dist_cdr = ClockDomainsRenamer("rsys")
+            fifos_cdr = ClockDomainsRenamer({"write": "rsys", "read": "rio"})
+            gates_cdr = ClockDomainsRenamer("rio")
+            output_driver_cdr = ClockDomainsRenamer("rio")
+        else:
+            raise ValueError
+
+        fine_ts_width = max(rtlink.get_fine_ts_width(c.interface)
+                            for c in channels)
+        seqn_width = layouts.seqn_width(lane_count, fifo_depth)
+
+        self.submodules.lane_dist = lane_dist_cdr(
+            LaneDistributor(lane_count, seqn_width,
+                            layouts.fifo_payload(channels), fine_ts_width,
+                            enable_spread=enable_spread,
+                            interface=interface))
+        self.submodules.fifos = fifos_cdr(
+            FIFOs(lane_count, fifo_depth,
+                  layouts.fifo_payload(channels), mode))
+        self.submodules.gates = gates_cdr(
+            Gates(lane_count, seqn_width,
+                  layouts.fifo_payload(channels),
+                  layouts.output_network_payload(channels)))
+        self.submodules.output_driver = output_driver_cdr(
+            OutputDriver(channels, lane_count, seqn_width))
+
+        for o, i in zip(self.lane_dist.output, self.fifos.input):
+            self.comb += o.connect(i)
+        for o, i in zip(self.fifos.output, self.gates.input):
+            self.comb += o.connect(i)
+        for o, i in zip(self.gates.output, self.output_driver.input):
+            self.comb += i.eq(o)
+
+    @property
+    def cri(self):
+        return self.lane_dist.cri
+
+    @property
+    def minimum_coarse_timestamp(self):
+        return self.lane_dist.minimum_coarse_timestamp
+
+    @property
+    def coarse_timestamp(self):
+        return self.gates.coarse_timestamp
+
+    @property
+    def collision(self):
+        return self.output_driver.collision
+
+    @property
+    def collision_channel(self):
+        return self.output_driver.collision_channel
+
+    @property
+    def busy(self):
+        return self.output_driver.busy
+
+    @property
+    def busy_channel(self):
+        return self.output_driver.busy_channel