From 5e994071ce3c738b20824fec95a40f3d2f76db42 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Tue, 14 Oct 2014 15:54:28 +0800
Subject: [PATCH] examples: add RTIO skew

---
 examples/rtio_skew.py | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 examples/rtio_skew.py

diff --git a/examples/rtio_skew.py b/examples/rtio_skew.py
new file mode 100644
index 000000000..f408190c6
--- /dev/null
+++ b/examples/rtio_skew.py
@@ -0,0 +1,36 @@
+from artiq import *
+from artiq.devices import corecom_serial, core, rtio_core
+
+
+def print_skew(p):
+    print("Input/output skew: {} ns".format(p))
+
+
+def print_failed():
+    print("Pulse was not received back")
+
+
+class RTIOSkew(AutoContext):
+    parameters = "i o"
+
+    @kernel
+    def run(self):
+        with parallel:
+            self.i.gate_rising(10*us)
+            with sequential:
+                delay(5*us)
+                out_t = now()
+                self.o.pulse(5*us)
+        in_t = self.i.timestamp()
+        if in_t < 0*s:
+            print_failed()
+        else:
+            print_skew(int((out_t - in_t)/(1*ns)))
+
+if __name__ == "__main__":
+    with corecom_serial.CoreCom() as com:
+        coredev = core.Core(com)
+        exp = RTIOSkew(core=coredev,
+                       i=rtio_core.RTIOIn(core=coredev, channel=0),
+                       o=rtio_core.RTIOOut(core=coredev, channel=1))
+        exp.run()