git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@7555 35acf78f-673a-0410-8e92-d51de3d6d3f4

1 files changed, 152 insertions, 0 deletions

diff --git a/os/hal/dox/adc.dox b/os/hal/dox/adc.dox
new file mode 100644
index 000000000..3483a47ac
--- /dev/null
+++ b/os/hal/dox/adc.dox
@@ -0,0 +1,152 @@
+/*

+    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,

+                 2011,2012,2013 Giovanni Di Sirio.

+

+    This file is part of ChibiOS/RT.

+

+    ChibiOS/RT is free software; you can redistribute it and/or modify

+    it under the terms of the GNU General Public License as published by

+    the Free Software Foundation; either version 3 of the License, or

+    (at your option) any later version.

+

+    ChibiOS/RT is distributed in the hope that it will be useful,

+    but WITHOUT ANY WARRANTY; without even the implied warranty of

+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+    GNU General Public License for more details.

+

+    You should have received a copy of the GNU General Public License

+    along with this program.  If not, see <http://www.gnu.org/licenses/>.

+

+                                      ---

+

+    A special exception to the GPL can be applied should you wish to distribute

+    a combined work that includes ChibiOS/RT, without being obliged to provide

+    the source code for any proprietary components. See the file exception.txt

+    for full details of how and when the exception can be applied.

+*/

+

+/**

+ * @defgroup ADC ADC Driver

+ * @brief Generic ADC Driver.

+ * @details This module implements a generic ADC (Analog to Digital Converter)

+ *          driver supporting a variety of buffer and conversion modes.

+ * @pre     In order to use the ADC driver the @p HAL_USE_ADC option

+ *          must be enabled in @p halconf.h.

+ *

+ * @section adc_1 Driver State Machine

+ * The driver implements a state machine internally, not all the driver

+ * functionalities can be used in any moment, any transition not explicitly

+ * shown in the following diagram has to be considered an error and shall

+ * be captured by an assertion (if enabled).

+ * @if LATEX_PDF

+ * @dot

+  digraph example {

+    rankdir="LR";

+    size="5, 7";

+

+    node [shape=circle, fontname=Helvetica, fontsize=8, fixedsize="true", width="0.9", height="0.9"];

+    edge [fontname=Helvetica, fontsize=8];

+

+    stop  [label="ADC_STOP\nLow Power"];

+    uninit [label="ADC_UNINIT", style="bold"];

+    ready [label="ADC_READY\nClock Enabled"];

+    active [label="ADC_ACTIVE\nConverting"];

+    error [label="ADC_ERROR\nError"];

+    complete [label="ADC_COMPLETE\nComplete"];

+

+    uninit -> stop [label="\n adcInit()", constraint=false];

+    stop -> ready [label="\nadcStart()"];

+    ready -> ready [label="\nadcStart()\nadcStopConversion()"];

+    ready -> stop [label="\nadcStop()"];

+    stop -> stop [label="\nadcStop()"];

+    ready -> active [label="\nadcStartConversion() (async)\nadcConvert() (sync)"];

+    active -> ready [label="\nadcStopConversion()\nsync return"];

+    active -> active [label="\nasync callback (half buffer, circular)\nasync callback (full buffer)\n>acg_endcb<"];

+    active -> complete [label="\n\nasync callback (full buffer)\n>end_cb<"];

+    active -> error [label="\n\nasync callback (error)\n>error_cb<"];

+    complete -> active [label="\nadcStartConversionI()\nthen\ncallback return"];

+    complete -> ready [label="\ncallback return"];

+    error -> active [label="\nadcStartConversionI()\nthen\ncallback return"];

+    error -> ready [label="\ncallback return"];

+  }

+ * @enddot

+ * @else

+ * @dot

+  digraph example {

+    rankdir="LR";

+

+    node [shape=circle, fontname=Helvetica, fontsize=8, fixedsize="true", width="0.9", height="0.9"];

+    edge [fontname=Helvetica, fontsize=8];

+

+    stop  [label="ADC_STOP\nLow Power"];

+    uninit [label="ADC_UNINIT", style="bold"];

+    ready [label="ADC_READY\nClock Enabled"];

+    active [label="ADC_ACTIVE\nConverting"];

+    error [label="ADC_ERROR\nError"];

+    complete [label="ADC_COMPLETE\nComplete"];

+

+    uninit -> stop [label="\n adcInit()", constraint=false];

+    stop -> ready [label="\nadcStart()"];

+    ready -> ready [label="\nadcStart()\nadcStopConversion()"];

+    ready -> stop [label="\nadcStop()"];

+    stop -> stop [label="\nadcStop()"];

+    ready -> active [label="\nadcStartConversion() (async)\nadcConvert() (sync)"];

+    active -> ready [label="\nadcStopConversion()\nsync return"];

+    active -> active [label="\nasync callback (half buffer, circular)\nasync callback (full buffer)\n>acg_endcb<"];

+    active -> complete [label="\n\nasync callback (full buffer)\n>end_cb<"];

+    active -> error [label="\n\nasync callback (error)\n>error_cb<"];

+    complete -> active [label="\nadcStartConversionI()\nthen\ncallback return"];

+    complete -> ready [label="\ncallback return"];

+    error -> active [label="\nadcStartConversionI()\nthen\ncallback return"];

+    error -> ready [label="\ncallback return"];

+  }

+ * @enddot

+ * @endif

+ *

+ * @section adc_2 ADC Operations

+ * The ADC driver is quite complex, an explanation of the terminology and of

+ * the operational details follows.

+ *

+ * @subsection adc_2_1 ADC Conversion Groups

+ * The @p ADCConversionGroup is the objects that specifies a physical

+ * conversion operation. This structure contains some standard fields and

+ * several implementation-dependent fields.<br>

+ * The standard fields define the CG mode, the number of channels belonging

+ * to the CG and the optional callbacks.<br>

+ * The implementation-dependent fields specify the physical ADC operation

+ * mode, the analog channels belonging to the group and any other

+ * implementation-specific setting. Usually the extra fields just mirror

+ * the physical ADC registers, please refer to the vendor's MCU Reference

+ * Manual for details about the available settings. Details are also available

+ * into the documentation of the ADC low level drivers and in the various

+ * sample applications.

+ *

+ * @subsection adc_2_2 ADC Conversion Modes

+ * The driver supports several conversion modes:

+ * - <b>One Shot</b>, the driver performs a single group conversion then stops.

+ * - <b>Linear Buffer</b>, the driver performs a series of group conversions

+ *   then stops. This mode is like a one shot conversion repeated N times,

+ *   the buffer pointer increases after each conversion. The buffer is

+ *   organized as an S(CG)*N samples matrix, when S(CG) is the conversion

+ *   group size (number of channels) and N is the buffer depth (number of

+ *   repeated conversions).

+ * - <b>Circular Buffer</b>, much like the linear mode but the operation does

+ *   not stop when the buffer is filled, it is automatically restarted

+ *   with the buffer pointer wrapping back to the buffer base.

+ * .

+ * @subsection adc_2_3 ADC Callbacks

+ * The driver is able to invoke callbacks during the conversion process. A

+ * callback is invoked when the operation has been completed or, in circular

+ * mode, when the buffer has been filled and the operation is restarted. In

+ * circular mode a callback is also invoked when the buffer is half filled.<br>

+ * The "half filled" and "filled" callbacks in circular mode allow to

+ * implement "streaming processing" of the sampled data, while the driver is

+ * busy filling one half of the buffer the application can process the

+ * other half, this allows for continuous interleaved operations.

+ *

+ * The driver is not thread safe for performance reasons, if you need to access

+ * the ADC bus from multiple threads then use the @p adcAcquireBus() and

+ * @p adcReleaseBus() APIs in order to gain exclusive access.

+ *

+ * @ingroup IO

+ */