STM32f4标准固件库

/** @page I2S_DataExchangePolling I2S communication example using polling mode @verbatim ******************** (C) COPYRIGHT 2016 STMicroelectronics ******************* * @file I2S/I2S_TwoBoards/I2S_DataExchangePolling/readme.txt * @author MCD Application Team * @version V1.8.0 * @date 04-November-2016 * @brief Description of the I2S full duplex communication example. ****************************************************************************** * * 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 This example shows how to to configure the I2S for full duplex communication, based on polling mode and through I2S firmware library. - Hardware Description To use this example, you need to load it on two STM32 boards (let's call them BoardA and BoardB) then connect these two boards through I2S lines and GND. In the firmware example uncomment the dedicated line in the main.h file to use the I2S peripheral as STM32 Master device or as STM32 Slave device. @verbatim *------------------------------------------------------------------------------* | BoardA BoardB | | ____________________ ____________________ | | | __________ | | __________ | | | | | |____|_______WS________|____| | | | | | |I2S Master|____|_______CK________|____|I2S Slave | | | | | | TX |____|_______SD________|____| RX | | | | | |__________| | | |__________| | | | | | I2S_ext | | | | I2S_ext | | | | | | Slave RX |____|_____ext_SD______|____| Slave TX | | | | | |__________| | | |__________| | | | | | | | | | | O LED1 | | O LED1 | | | | O LED2 | | O LED2 | | | | O LED3 | | O LED3 | | | | O LED4 | | O LED4 | | | | | | | | | | GND O--|-----------------|--O GND | | | |____________________| |____________________| | | | | | *------------------------------------------------------------------------------* @endverbatim @note The connection between the pins should use a short wires and a common Ground. - Software Description In this example, the I2S full duplex interface is based on the I2S2 peripheral with an extra instance called I2S_ext used only for full duplex communication and can operate only in Slave Mode. Both I2Ss are configured as follows: - Audio Frequency: 8 KHz - Standard: Phillips - MCLK Output: disabled - CPOL: Low - Data Format: 16b In master board, I2S2 and I2S2_ext are enabled so I2S2 can deliver CK and WS to I2S2_ext. The I2S2 peripheral is configured as Master Transmitter and I2S2_ext is configured as Slave Receiver. Whereas in Slave Board, the I2S2 peripheral is configured as Slave Receiver ans I2S2_ext is configured as Slave Transmitter. - The Slave must be launched before the Master. - The Master start the communication by sending aTxMasterBuffer buffer through SD pin in the same time he receive a buffer through ext_SD pin, which is stored in aRxMasterBuffer. - The Slave Start the communication when the clock is already available on CK pin the Buffer received from master through SD pin,is stored in RxSlaveBuffer, in the same time the aTxSlaveBuffer buffer is transmitted through ext_SD pin. - In Master Board, after the Communication end, if the received buffer is correct the LED2 and LED4 turns ON. - In Slave Board, after the Communication end, if the received buffer is correct the LED 3 turns ON. @note In this example the I2S_MCK signal is not used in the communication, this signal is needed to be provided to external codec audio component. In both boards, the SysTick is configured to generate interrupt each 10ms. A dedicated counter inside the SysTick ISR is used to toggle LED1 each 100ms indicating that the firmware is running. @par Directory contents - I2S/I2S_TwoBoards/I2S_DataExchangePolling/system_stm32f4xx.c STM32F4xx system clock configuration file - I2S/I2S_TwoBoards/I2S_DataExchangePolling/stm32f4xx_conf.h Library Configuration file - I2S/I2S_TwoBoards/I2S_DataExchangePolling/stm32f4xx_it.c Interrupt handlers - I2S/I2S_TwoBoards/I2S_DataExchangePolling/stm32f4xx_it.h Interrupt handlers header file - I2S/I2S_TwoBoards/I2S_DataExchangePolling/main.c Main program - I2S/I2S_TwoBoards/I2S_DataExchangePolling/main.h Main program header file @par Hardware and Software environment - This example runs on STM32F405xx/407xx and STM32F415xx/417xx, STM32F427xx/437xx devices. - This example has been tested with STMicroelectronics STM324xG-EVAL (STM32F40xx/ STM32F41xx Devices) and STM32437I-EVAL (STM32F427xx/STM32F437xx Devices) evaluation boards and can be easily tailored to any other supported device and development board. - STM324xG-EVAL/STM32437I-EVAL Set-up - Use LED1, LED2, LED3 and LED4 connected respectively to PG.06, PG.08, PI.09 and PC.07 pins - Connect BoardA I2S2_WS pin (PB12) to BoardB I2S2_WS pin (PB12) - Connect BoardA I2S2_CK pin (PB13) to BoardB I2S2_CK pin (PB13) - Connect BoardA I2S2_SD pin (PB15) to BoardB I2S2_SD pin (PB15) - Connect BoardA I2S2ext_SD pin (PI2) to BoardB I2S2ext_SD pin (PI2) @par How to use it ? In order to make the program work, you must do the following: - Copy all source files from this example folder to the template folder under Project\STM32F4xx_StdPeriph_Templates - Open your preferred toolchain - Select the project workspace related to the used device - If "STM32F40_41xxx" is selected as default project Add the following files in the project source list: - Utilities\STM32_EVAL\STM3240_41_G_EVAL\stm324xg_eval.c - If "STM32F427_437xx" is selected as default project Add the following files in the project source list: - Utilities\STM32_EVAL\STM324x7I_EVAL\stm324x7i_eval.c - Rebuild all files and load your image into target memory - Run the example * <h3><center>&copy; COPYRIGHT STMicroelectronics</center></h3> */