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_icu.dox | 107 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 os/hal/dox/hal_icu.dox (limited to 'os/hal/dox/hal_icu.dox') diff --git a/os/hal/dox/hal_icu.dox b/os/hal/dox/hal_icu.dox new file mode 100644 index 000000000..710c388ae --- /dev/null +++ b/os/hal/dox/hal_icu.dox @@ -0,0 +1,107 @@ +/* + 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 ICU ICU Driver + * @brief Generic ICU Driver. + * @details This module implements a generic ICU (Input Capture Unit) driver. + * The purpose of the driver is to measure period and duty cycle of + * an input digital signal (PWM input). + * @pre In order to use the ICU driver the @p HAL_USE_ICU option + * must be enabled in @p halconf.h. + * + * @section icu_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 { + size="5, 7"; + rankdir="LR"; + + node [shape=circle, fontname=Sans, fontsize=8, fixedsize="true", width="0.9", height="0.9"]; + edge [fontname=Sans, fontsize=8]; + + stop [label="ICU_STOP\nLow Power"]; + uninit [label="ICU_UNINIT", style="bold"]; + ready [label="ICU_READY\nClock Enabled"]; + waiting [label="ICU_WAITING"]; + active [label="ICU_ACTIVE"]; + + uninit -> stop [label=" icuInit()", constraint=false]; + stop -> stop [label="\nicuStop()"]; + stop -> ready [label="\nicuStart()"]; + ready -> stop [label="\nicuStop()"]; + ready -> ready [label="\nicuStart()\nicuStopCapture()"]; + ready -> waiting [label="\nicuStartCapture()"]; + waiting -> active [label="\nFirst Activation Edge\nicuWaitCapture()"]; + waiting -> ready [label="\nicuStopCapture()"]; + active -> ready [label="\nicuStopCapture()"]; + active -> active [label="\nActivation Edge\n>period_cb<"]; + active -> active [label="\nDe-activation Edge\n>width_cb<"]; + } + * @enddot + * @else + * @dot + digraph example { + rankdir="LR"; + + node [shape=circle, fontname=Sans, fontsize=8, fixedsize="true", width="0.9", height="0.9"]; + edge [fontname=Sans, fontsize=8]; + + stop [label="ICU_STOP\nLow Power"]; + uninit [label="ICU_UNINIT", style="bold"]; + ready [label="ICU_READY\nClock Enabled"]; + waiting [label="ICU_WAITING"]; + active [label="ICU_ACTIVE"]; + + uninit -> stop [label=" icuInit()", constraint=false]; + stop -> stop [label="\nicuStop()"]; + stop -> ready [label="\nicuStart()"]; + ready -> stop [label="\nicuStop()"]; + ready -> ready [label="\nicuStart()\nicuStopCapture()"]; + ready -> waiting [label="\nicuStartCapture()"]; + waiting -> active [label="\nFirst Activation Edge\nicuWaitCapture()"]; + waiting -> ready [label="\nicuStopCapture()"]; + active -> ready [label="\nicuStopCapture()"]; + active -> active [label="\nActivation Edge\n>period_cb<"]; + active -> active [label="\nDe-activation Edge\n>width_cb<"]; + } + * @enddot + * @endif + * + * @section icu_2 ICU Operations. + * This driver abstracts a generic Input Capture Unit composed of: + * - A clock prescaler. + * - A main up counter. + * - Two capture registers triggered by the rising and falling edges on + * the sampled input. + * . + * The ICU unit can be programmed to synchronize on the rising or falling + * edge of the sample input: + * - ICU_INPUT_ACTIVE_HIGH, a rising edge is the start signal. + * - ICU_INPUT_ACTIVE_LOW, a falling edge is the start signal. + * . + * Callbacks are optionally invoked when: + * - On the PWM de-activation edge. + * - On the PWM activation edge, measurements for the previous cycle are + * available from this callback and can be retrieved using + * @p icuGetPeriodX() and @p icuGetWidthX(). + * . + * @ingroup HAL_NORMAL_DRIVERS + */ -- cgit v1.2.3