From 111bd3092c9c879f68af6acfd8b3564a514bbceb Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Fri, 17 Oct 2014 00:12:53 +0800
Subject: [PATCH] devices/rtio_core: add LLRTIOOut

---
 artiq/devices/rtio_core.py | 53 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/artiq/devices/rtio_core.py b/artiq/devices/rtio_core.py
index 02eabe634..0abfff860 100644
--- a/artiq/devices/rtio_core.py
+++ b/artiq/devices/rtio_core.py
@@ -2,6 +2,59 @@ from artiq.language.core import *
 from artiq.devices.runtime_exceptions import RTIOSequenceError
 
 
+class LLRTIOOut(AutoContext):
+    """Low-level RTIO output driver.
+
+    Allows setting RTIO outputs at arbitrary times, without time unit
+    conversion and without zero-length transition suppression.
+
+    This is meant to be used mostly in drivers; consider using
+    ``RTIOOut`` instead.
+
+    """
+    parameters = "channel"
+
+    def build(self):
+        self.previous_timestamp = int64(0)  # in RTIO cycles
+        self._set_oe()
+
+    kernel_attr = "previous_timestamp"
+
+    @kernel
+    def _set_oe(self):
+        syscall("rtio_oe", self.channel, 1)
+
+    @kernel
+    def set_value(self, t, value):
+        """Sets the value of the RTIO channel.
+
+        :param t: timestamp in RTIO cycles (64-bit integer).
+        :param value: value to set at the output.
+
+        """
+        if t <= self.previous_timestamp:
+            raise RTIOSequenceError
+        syscall("rtio_set", t, self.channel, value)
+        self.previous_timestamp = t
+
+    @kernel
+    def on(self, t):
+        """Turns the RTIO channel on.
+
+        :param t: timestamp in RTIO cycles (64-bit integer).
+
+        """
+        self.set_value(t, 1)
+
+    @kernel
+    def off(self, t):
+        """Turns the RTIO channel off.
+
+        :param t: timestamp in RTIO cycles (64-bit integer).
+
+        """
+        self.set_value(t, 0)
+
 class _RTIOBase(AutoContext):
     parameters = "channel"