From 490c9815a295865b305c96c65c394336f68a396f Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Thu, 14 Sep 2017 19:53:21 +0800
Subject: [PATCH] rtio/sed: add TSC/gate (untested)

---
 artiq/gateware/rtio/sed/tsc_gate.py | 38 +++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 artiq/gateware/rtio/sed/tsc_gate.py

diff --git a/artiq/gateware/rtio/sed/tsc_gate.py b/artiq/gateware/rtio/sed/tsc_gate.py
new file mode 100644
index 000000000..38e35081e
--- /dev/null
+++ b/artiq/gateware/rtio/sed/tsc_gate.py
@@ -0,0 +1,38 @@
+from migen import *
+
+from artiq.gateware.rtio.sed import layouts
+
+
+__all__ = ["TSCGate"]
+
+
+
+class TSCGate(Module):
+    def __init__(self, lane_count, seqn_width, layout_fifo_payload, layout_output_network_payload):
+        self.input = [Record(layouts.fifo_egress(seqn_width, layout_fifo_payload))
+                      for _ in range(lane_count)]
+        self.output = [Record(layouts.output_network_node(seqn_width, layout_output_network_payload))
+                       for _ in range(lane_count)]
+
+        if hasattr(self.output[0], "fine_ts"):
+            fine_ts_width = len(self.output[0].fine_ts)
+        else:
+            fine_ts_width = 0
+        self.tsc = Signal(64-fine_ts_width)
+
+        # # #
+
+        self.sync += self.tsc.eq(self.tsc + 1)
+
+        for input, output in zip(self.input, self.output):
+            for field, _ in output.payload.layout:
+                if field == "fine_ts":
+                    self.sync += output.payload.fine_ts.eq(input.payload.timestamp[:fine_ts_width])
+                else:
+                    self.sync += getattr(output.payload, field).eq(getattr(input.payload, field))
+            self.sync += output.seqn.eq(input.seqn)
+            self.comb += output.replace_occured.eq(0)
+
+            self.comb += input.re.eq(input.payload.timestamp[fine_ts_width:] == self.tsc)
+            self.sync += ouput.valid.eq(input.re & input.readable)
+