86 lines
3.5 KiB
Plaintext
86 lines
3.5 KiB
Plaintext
/*
|
|
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 GPT GPT Driver
|
|
* @brief Generic GPT Driver.
|
|
* @details This module implements a generic GPT (General Purpose Timer)
|
|
* driver. The timer can be programmed in order to trigger callbacks
|
|
* after a specified time period or continuously with a specified
|
|
* interval.
|
|
* @pre In order to use the GPT driver the @p HAL_USE_GPT option
|
|
* must be enabled in @p halconf.h.
|
|
*
|
|
* @section gpt_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];
|
|
|
|
stop [label="GPT_STOP\nLow Power"];
|
|
uninit [label="GPT_UNINIT", style="bold"];
|
|
ready [label="GPT_READY\nClock Enabled"];
|
|
continuous [label="GPT_CONT..S\nContinuous\nMode"];
|
|
oneshot [label="GPT_ONESHOT\nOne Shot\nMode"];
|
|
|
|
uninit -> stop [label=" gptInit()", constraint=false];
|
|
stop -> stop [label="\ngptStop()"];
|
|
stop -> ready [label="\ngptStart()"];
|
|
ready -> stop [label="\ngptStop()"];
|
|
ready -> ready [label="\ngptStart()"];
|
|
ready -> continuous [label="\ngptStartContinuous()"];
|
|
continuous -> ready [label="\ngptStopTimer()"];
|
|
continuous -> continuous [label=">callback<"];
|
|
ready -> oneshot [label="\ngptStartOneShot()\ngptPolledDelay()"];
|
|
oneshot -> ready [label="\n>callback<\nor\nDelay Over"];
|
|
}
|
|
* @enddot
|
|
*
|
|
* @section gpt_2 GPT Operations.
|
|
* This driver abstracts a generic 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. A callback is invoked when this happens.
|
|
* .
|
|
* The timer can operate in three different modes:
|
|
* - <b>Continuous Mode</b>, a periodic callback is invoked until the driver
|
|
* is explicitly stopped.
|
|
* - <b>One Shot Mode</b>, a callback is invoked after the programmed period
|
|
* and then the timer automatically stops.
|
|
* - <b>Delay Mode</b>, the timer is used for inserting a brief delay into
|
|
* the execution flow, no callback is invoked in this mode.
|
|
* .
|
|
* @ingroup IO
|
|
*/
|