DMA.zip_DMA flash_flash dma

/******************** (C) COPYRIGHT 2007 STMicroelectronics ******************** * File Name : readme.txt * Author : MCD Application Team * Version : V1.0 * Date : 10/08/2007 * Description : Description of the DMA Example3. ******************************************************************************** * THE PRESENT SOFTWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME. * AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT, * INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE * CONTENT OF SUCH SOFTWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING * INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS. *******************************************************************************/ 本例展示了如何利用4个DMA通道来实现把内存中4块数据两两通过SPI1和SPI2交换。即SPI1 Tx buffer中的数据由DMA传送至SPI1发送端发送至SPI2，再由DMA从SPI2接收端传送至SPI2 Rx buffer。SPI2 Tx buffer中的数据也由同样的方法传送到SPI1 Rx buffer。 在本例中SPI1工作在主模式（master）而SPI2工作在从模式（slave）。SPI1的NSS管脚由软件配置。DMA通道2用来把SPI1接收到的数据传送进SPI1 Rx buffer；DMA通道4用来把SPI2接收到的数据传送进SPI2 Rx buffer。相应的DMA通道3用来把SPI1 Tx buffer中的待发送数据送进SPI1发送端，DMA通道5用来把SPI2 Tx buffer中的待发送数据送进SPI2发送端。 一旦SPI1_CR2和SPI2_CR2两寄存器中的TxDMAEN 和 RxDMAEN比特被置一，传送就会开始。传送结束以后，程序会比较SPI1 Tx buffer和SPI2 Rx buffer以及SPI2 Tx buffer和SPI1 Rx buffer中的数据。如果传输正确，则在STM3210B-LK1板上，LED1（LD4）会亮起，反之则是LED2（LD3）。 Example description =================== This example provides a description of how to use four DMA channels to transfer a data buffer from memory to SPI2 through SPI1 and a second data buffer from memory to SPI1 through SPI2 in ful-duplex mode. The NSS pins are configured by software to set SPI1 as the master and SPI2, as the slave. DMA Channel2 and Channel4 are configured to store the data received from SPI1 into the SPI1 Rx buffer and the data received from SPI2 into the SPI2 Rx buffer. DMA Channel3 is configured to transfer data from the SPI1 Tx buffer to the SPI1_DR register for transmission to SPI2. DMA Channel5 is configured to transfer data from the SPI2 Tx buffer to the SPI2_DR register for transmission to SPI1. As soon as the two SPI TxDMAEN and RxDMAEN bits are set in the SPI1_CR2 and SPI2_CR2 registers, DMA Channel3 and Channel5 start transmitting the SPI1 and SPI2 Tx buffers, respectively, at the same time. At the same moment, the data received on SPI1 and SPI2 are transferred by DMA Channel2 and Channel4 to the SPI1 and SPI2 Rx buffers, respectively. Then the system checks that all the data were transmitted and received by the DMA Channels. The last received data on SPI1 and SPI2 are the CRC values sent by SPI2 and SPI1, respectively. The transmitted buffer and the received buffer are compared to check that all data have been correctly transferred. Directory contents ================== stm32f10x_conf.h Library Configuration file stm32f10x_it.c Interrupt handlers stm32f10x_it.h Interrupt handlers header file main.c Main program Hardware environment ==================== - Connect SPI1 SCK pin (PA.05) to SPI2 SCK pin (PB.13) - Connect SPI1 MISO pin (PA.06) to SPI2 MISO pin (PB.14) - Connect SPI1 MOSI pin (PA.07) to SPI2 MOSI pin (PB.15) How to use it ============= In order to make the program work, you must do the following : - Create a project and setup all your toolchain's start-up files - Compile the directory content files and required Library files : + stm32f10x_lib.c + stm32f10x_dma.c + stm32f10x_rcc.c + stm32f10x_spi.c + stm32f10x_nvic.c + stm32f10x_gpio.c + stm32f10x_flash.c - Link all compiled files and load your image into either RAM or FLASH - Run the example ******************* (C) COPYRIGHT 2007 STMicroelectronics *****END OF FILE******