From 051dd3958373c27c9ffeb06da004dca0023003b6 Mon Sep 17 00:00:00 2001
From: gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4>
Date: Mon, 1 Sep 2014 08:27:52 +0000
Subject: git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@7224
 35acf78f-673a-0410-8e92-d51de3d6d3f4

---
 os/hal/dox/pwm.dox | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 os/hal/dox/pwm.dox

(limited to 'os/hal/dox/pwm.dox')

diff --git a/os/hal/dox/pwm.dox b/os/hal/dox/pwm.dox
new file mode 100644
index 000000000..719cdc656
--- /dev/null
+++ b/os/hal/dox/pwm.dox
@@ -0,0 +1,69 @@
+/*
+    ChibiOS/HAL - Copyright (C) 2006,2007,2008,2009,2010,
+                  2011,2012,2013,2014 Giovanni Di Sirio.
+
+    This file is part of ChibiOS/HAL 
+
+    ChibiOS/HAL 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/>.
+*/
+
+/**
+ * @defgroup PWM PWM Driver
+ * @brief   Generic PWM Driver.
+ * @details This module implements a generic PWM (Pulse Width Modulation)
+ *          driver.
+ * @pre     In order to use the PWM driver the @p HAL_USE_PWM option
+ *          must be enabled in @p halconf.h.
+ *
+ * @section pwm_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).
+ * @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];
+    uninit [label="PWM_UNINIT", style="bold"];
+    stop  [label="PWM_STOP\nLow Power"];
+    ready [label="PWM_READY\nClock Enabled"];
+    uninit -> stop [label="pwmInit()"];
+    stop -> stop [label="pwmStop()"];
+    stop -> ready [label="pwmStart()"];
+    ready -> stop [label="pwmStop()"];
+    ready -> ready [label="pwmEnableChannel()\npwmDisableChannel()"];
+  }
+ * @enddot
+ *
+ * @section pwm_2 PWM Operations.
+ * This driver abstracts a generic PWM timer composed of:
+ * - A clock prescaler.
+ * - A main up counter.
+ * - A comparator register that resets the main counter to zero when the limit
+ *   is reached. An optional callback can be generated when this happens.
+ * - An array of @p PWM_CHANNELS PWM channels, each channel has an output,
+ *   a comparator and is able to invoke an optional callback when a comparator
+ *   match with the main counter happens.
+ * .
+ * A PWM channel output can be in two different states:
+ * - <b>IDLE</b>, when the channel is disabled or after a match occurred.
+ * - <b>ACTIVE</b>, when the channel is enabled and a match didn't occur yet
+ *   in the current PWM cycle.
+ * .
+ * Note that the two states can be associated to both logical zero or one in
+ * the @p PWMChannelConfig structure.
+ *
+ * @ingroup IO
+ */
-- 
cgit v1.2.3