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| author | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2014-09-01 08:27:52 +0000 |
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| committer | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2014-09-01 08:27:52 +0000 |
| commit | 051dd3958373c27c9ffeb06da004dca0023003b6 (patch) | |
| tree | 229af7fcf59f7a493d4c5a04fcef681c171683eb /os/hal/dox/pwm.dox | |
| parent | 7d1b097edcd86c87e738069a64d41e8b0cf9fd4b (diff) | |
| download | ChibiOS-051dd3958373c27c9ffeb06da004dca0023003b6.tar.gz ChibiOS-051dd3958373c27c9ffeb06da004dca0023003b6.tar.bz2 ChibiOS-051dd3958373c27c9ffeb06da004dca0023003b6.zip | |
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@7224 35acf78f-673a-0410-8e92-d51de3d6d3f4
Diffstat (limited to 'os/hal/dox/pwm.dox')
| -rw-r--r-- | os/hal/dox/pwm.dox | 69 |
1 files changed, 69 insertions, 0 deletions
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
+ */
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