Incorporated comments.

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

diff --git a/doc/html/tep114.html b/doc/html/tep114.html
index f40baace0cb9296252fd7609daec57d07fa54329..0716697f9b2e32a22bd8b54303808c1645511c28 100644 (file)
--- a/doc/html/tep114.html
+++ b/doc/html/tep114.html
@@ -303,9 +303,9 @@ ul.auto-toc {
 <td>Gilman Tolle, Philip Levis, and David Gay</td></tr>
 <tr class="field"><th class="docinfo-name">Draft-Created:</th><td class="field-body">30-Oct-2005</td>
 </tr>
-<tr class="field"><th class="docinfo-name">Draft-Version:</th><td class="field-body">1.1.2.3</td>
+<tr class="field"><th class="docinfo-name">Draft-Version:</th><td class="field-body">1.6</td>
 </tr>
-<tr class="field"><th class="docinfo-name">Draft-Modified:</th><td class="field-body">2006-06-09</td>
+<tr class="field"><th class="docinfo-name">Draft-Modified:</th><td class="field-body">2006-12-12</td>
 </tr>
 <tr class="field"><th class="docinfo-name">Draft-Discuss:</th><td class="field-body">TinyOS Developer List &lt;tinyos-devel at mail.millennium.berkeley.edu&gt;</td>
 </tr>
@@ -354,12 +354,12 @@ and so could be easily placed in a task.</p>
 Many sensors today are digital. To sample these sensors, the MCU sends
 a sample command and receives the corresponding data over a bus (e.g.,
 SPI, I2C). The latency involved, combined with possible Resource
-arbitration [_tep108], means that these bus operations are often
+arbitration <a class="footnote-reference" href="#id2" id="id1" name="id1">[1]</a>, means that these bus operations are often
 synchronous code. In the command direction, this can force a task
 allocation to convert async to sync; in the event direction, the
 application has to deal with async code even though the event is, in
 practice, in a task.</p>
-<p>Finallly, the simplicity of the ADC interface has led many sensors to
+<p>Finally, the simplicity of the ADC interface has led many sensors to
 introduce several new ones for calibration and control, such as
 <tt class="docutils literal"><span class="pre">Mic</span></tt> and <tt class="docutils literal"><span class="pre">MagSetting</span></tt>. Because ADCs generally do not have error
 conditions, the ADC interface has no way to signal that a sample
@@ -422,6 +422,12 @@ fail while a read is pending MUST provide a ReadWrite interface.</p>
 <p>If the <tt class="docutils literal"><span class="pre">result</span></tt> parameter of the <tt class="docutils literal"><span class="pre">Read.readDone</span></tt> and
 <tt class="docutils literal"><span class="pre">ReadWrite.readDone</span></tt> events is not SUCCESS, then the memory of the
 <tt class="docutils literal"><span class="pre">val</span></tt> parameter MUST be filled with zeroes.</p>
+<p>If the call to <tt class="docutils literal"><span class="pre">Read.read</span></tt> has returned SUCCESS, but the
+<tt class="docutils literal"><span class="pre">Read.readDone</span></tt> event has not yet been signalled, then a subsequent
+call to <tt class="docutils literal"><span class="pre">Read.read</span></tt> 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.</p>
 <p>Examples of sensors that would be suited to this class of interface
 include many basic sensors, such as photo, temp, voltage, and ADC
 readings.</p>
@@ -472,29 +478,6 @@ passing by value is inefficient, such as a two-axis digital
 accelerometer.</p>
 </div>
 <div class="section">
-<h2><a id="metadata-and-shifting" name="metadata-and-shifting">3.3 Metadata and Shifting</a></h2>
-<p>Generally, simple types are made up of octets. However, sensor values
-often have levels of precision besides a multiple of 8. Any value
-contained in a simple type MUST be left shifted so that it covers as
-much of the type's range as possible. For example, if a 12-bit ADC
-reading is presented as a 16-bit Read interface:</p>
-<pre class="literal-block">
-component DemoSensorC {
-  provides interface Read&lt;uint16_t&gt;;
-}
-</pre>
-<p>then the 12-bit value MUST be shifted left so that its range is 0x0000
-- 0xfff0, rather than 0x0000 - 0x0fff. A device MAY specify the
-precision of one of its interfaces with the DeviceMetadata interface:</p>
-<pre class="literal-block">
-interface DeviceMetadata {
-  command uint8_t getSignificantBits();
-}
-</pre>
-<p>The name of the instance of DeviceMetadata SHOULD clearly indicate
-which interface it corresponds to.</p>
-</div>
-<div class="section">
 <h2><a id="single-phase-scalar-i-o" name="single-phase-scalar-i-o">3.4 Single-Phase Scalar I/O</a></h2>
 <p>Some devices may have their state cached or readily available. In
 these cases, the device can provide a single-phase instead of
@@ -664,6 +647,15 @@ connect a sensor into a more general system.</p>
 <div class="line"><br /></div>
 </div>
 </div>
+<div class="section">
+<h1><a id="citations" name="citations">6. Citations</a></h1>
+<table class="docutils footnote" frame="void" id="id2" rules="none">
+<colgroup><col class="label" /><col /></colgroup>
+<tbody valign="top">
+<tr><td class="label"><a class="fn-backref" href="#id1" name="id2">[1]</a></td><td>TEP 108: Resource Arbitration.</td></tr>
+</tbody>
+</table>
+</div>
 </div>
 </body>
 </html>