From a3e9966359c432405c8ab1eb49a27133e5271ba2 Mon Sep 17 00:00:00 2001 From: Giovanni Di Sirio Date: Mon, 21 Jan 2019 19:42:49 +0000 Subject: More renaming for consistency. git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@12571 110e8d01-0319-4d1e-a829-52ad28d1bb01 --- os/hal/dox/hal_gpt.dox | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 os/hal/dox/hal_gpt.dox (limited to 'os/hal/dox/hal_gpt.dox') diff --git a/os/hal/dox/hal_gpt.dox b/os/hal/dox/hal_gpt.dox new file mode 100644 index 000000000..d75dab2b8 --- /dev/null +++ b/os/hal/dox/hal_gpt.dox @@ -0,0 +1,74 @@ +/* + ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/** + * @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: + * - Continuous Mode, a periodic callback is invoked until the driver + * is explicitly stopped. + * - One Shot Mode, a callback is invoked after the programmed period + * and then the timer automatically stops. + * - Delay Mode, the timer is used for inserting a brief delay into + * the execution flow, no callback is invoked in this mode. + * . + * @ingroup HAL_NORMAL_DRIVERS + */ -- cgit v1.2.3