/** @page GPIO_IOToggle GPIO_IOToggle Configuration example @verbatim ******************** (C) COPYRIGHT 2012 STMicroelectronics ******************* * @file GPIO_IOToggle/readme.txt * @author MCD Application Team * @version V1.1.0 * @date 20-September-2012 * @brief GPIO IO Toggle example Description. ****************************************************************************** * * Licensed under MCD-ST Liberty SW License Agreement V2, (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.st.com/software_license_agreement_liberty_v2 * * 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. * ****************************************************************************** @endverbatim @par Example Description GPIO ports are connected on AHB bus, using BSRR and BRR registers one cycle is required to set a pin and another one cycle to reset it. So GPIO pins can toggle at AHB clock divided by 2. This example describes how to use BSRR and BRR registers for maximum IO toggling. PE14 and PE15 when using the STM32F3-Discovery kit (configured in output pushpull mode) toggles in a forever loop: - Set PE14 and PE15 by setting corresponding bits in BSRR register - Reset PE14 and PE15 by setting corresponding bits in BRR register In this example, HCLK is configured at 72 MHz so PE14 and PE15 toggles at 36MHz. To achieve the maximum IO toggling frequency, you have to configure your compiler options for high speed optimization. @par Directory contents - GPIO_IOToggle/stm32f30x_conf.h Library Configuration file - GPIO_IOToggle/stm32f30x_it.c Interrupt handlers - GPIO_IOToggle/stm32f30x_it.h Header for stm32f30x_it.c - GPIO_IOToggle/main.c Main program - GPIO_IOToggle/main.h Header for main.c - GPIO_IOToggle/system_stm32f30x.c STM32F30x system source file @note The "system_stm32f30x.c" file contains the system clock configuration for STM32F30x devices, and is customized for use with STM32F3-Discovery Kit. The STM32F30x is configured to run at 72 MHz, following the three configuration below: + PLL_SOURCE_HSI - HSI (~8 MHz) used to clock the PLL, and the PLL is used as system clock source. + PLL_SOURCE_HSE - HSE (8 MHz) used to clock the PLL, and the PLL is used as system clock source. - The HSE crystal is not provided with the Discovery Kit, some hardware modification are needed in manner to connect this crystal. For more details, refer to section "4.10 OSC clock" in "STM32F3 discovery kit User manual (UM1570)" + PLL_SOURCE_HSE_BYPASS - HSE bypassed with an external clock (fixed at 8 MHz, coming from ST-Link circuit) used to clock the PLL, and the PLL is used as system clock source. - Some hardware modification are needed in manner to bypass the HSE with clock coming from the ST-Link circuit. For more details, refer to section "4.10 OSC clock" in "STM32F3 discovery kit User manual (UM1570)" User can select one of the three configuration in system_stm32f30x.c file (default configuration is PLL_SOURCE_HSE_BYPASS). @par Hardware and Software environment - This example runs on STM32F30x Devices. - This example has been tested with STMicroelectronics STM32F3-Discovery (MB1035) and can be easily tailored to any other supported device and development board. - STM32F3-Discovery Set-up - Connect the oscilloscope to the pins PE14 and PE15. @par How to use it ? In order to make the program work, you must do the following : + EWARM - Open the GPIO_IOToggle.eww workspace - Rebuild all files: Project->Rebuild all - Load project image: Project->Debug - Run program: Debug->Go(F5) + MDK-ARM - Open the GPIO_IOToggle.uvproj project - Rebuild all files: Project->Rebuild all target files - Load project image: Debug->Start/Stop Debug Session - Run program: Debug->Run (F5) + TASKING - Open TASKING toolchain. - Click on File->Import, select General->'Existing Projects into Workspace' and then click "Next". - Browse to TASKING workspace directory and select the project "GPIO_IOToggle" - Rebuild all project files: Select the project in the "Project explorer" window then click on Project->build project menu. - Run program: Select the project in the "Project explorer" window then click Run->Debug (F11) + TrueSTUDIO for ARM - Open the TrueSTUDIO for ARM toolchain. - Click on File->Switch Workspace->Other and browse to TrueSTUDIO workspace directory. - Click on File->Import, select General->'Existing Projects into Workspace' and then click "Next". - Browse to the TrueSTUDIO workspace directory and select the project "GPIO_IOToggle" - Rebuild all project files: Select the project in the "Project explorer" window then click on Project->build project menu. - Run program: Select the project in the "Project explorer" window then click Run->Debug (F11) * <h3><center>© COPYRIGHT STMicroelectronics</center></h3> */