Swapping HEAD and DEVEL branches

[tinyos-2.x.git] / doc / txt / tep114.txt

diff --git a/doc/txt/tep114.txt b/doc/txt/tep114.txt
index 56e975914c8255cb33e7a1fb750c492c167e37fb..2d4b2bd83f6bbed3a951f8999c3ef2b8d326bb86 100644 (file)
--- a/doc/txt/tep114.txt
+++ b/doc/txt/tep114.txt
@@ -137,6 +137,13 @@ If the ``result`` parameter of the ``Read.readDone`` and
 ``ReadWrite.readDone`` events is not SUCCESS, then the memory of the
 ``val`` parameter MUST be filled with zeroes.
 
 ``ReadWrite.readDone`` events is not SUCCESS, then the memory of the
 ``val`` parameter MUST be filled with zeroes.
 

+If the call to ``Read.read`` has returned SUCCESS, but the
+``Read.readDone`` event has not yet been signalled, then a subsequent
+call to ``Read.read`` MUST not return SUCCESS. This simple locking
+technique, as opposed to a more complex system in which multiple
+read/readDone pairs may be outstanding, is intended to reduce the
+complexity of code that is a client of a SID interface.
+

 Examples of sensors that would be suited to this class of interface
 include many basic sensors, such as photo, temp, voltage, and ADC
 readings.
 Examples of sensors that would be suited to this class of interface
 include many basic sensors, such as photo, temp, voltage, and ADC
 readings.