嵌入式stm32学习:DMA-存储到外设
2019-06-21 来源:eefocus
bsp_usart_dma.h
#ifndef __USART_DMA_H
#define __USART_DMA_H
#include 'stm32f4xx.h'
#include //USART #define DEBUG_USART USART1 #define DEBUG_USART_CLK RCC_APB2Periph_USART1 #define DEBUG_USART_RX_GPIO_PORT GPIOA #define DEBUG_USART_RX_GPIO_CLK RCC_AHB1Periph_GPIOA #define DEBUG_USART_RX_PIN GPIO_Pin_10 #define DEBUG_USART_RX_AF GPIO_AF_USART1 #define DEBUG_USART_RX_SOURCE GPIO_PinSource10 #define DEBUG_USART_TX_GPIO_PORT GPIOA #define DEBUG_USART_TX_GPIO_CLK RCC_AHB1Periph_GPIOA #define DEBUG_USART_TX_PIN GPIO_Pin_9 #define DEBUG_USART_TX_AF GPIO_AF_USART1 #define DEBUG_USART_TX_SOURCE GPIO_PinSource9 #define DEBUG_USART_BAUDRATE 115200 //DMA #define DEBUG_USART_DR_BASE (USART1_BASE+0x04) #define SENDBUFF_SIZE 5000 //发送的数据量 #define DEBUG_USART_DMA_CLK RCC_AHB1Periph_DMA2 #define DEBUG_USART_DMA_CHANNEL DMA_Channel_4 #define DEBUG_USART_DMA_STREAM DMA2_Stream7 void Debug_USART_Config(void); void USART_DMA_Config(void); #endif /* __USART1_H */ bsp_usart_dma.c /** ****************************************************************************** * 重定义C库函数printf到USART端口,使用DMA模式发送数据 ****************************************************************************** */ #include './usart/bsp_usart_dma.h' uint8_t SendBuff[SENDBUFF_SIZE]; /** * @brief USART GPIO 配置,工作模式配置。115200 8-N-1 */ void Debug_USART_Config(void) { GPIO_InitTypeDef GPIO_InitStructure; USART_InitTypeDef USART_InitStructure;---------------------------- RCC_AHB1PeriphClockCmd( DEBUG_USART_RX_GPIO_CLK|DEBUG_USART_TX_GPIO_CLK, ENABLE); /* Enable UART clock */ RCC_APB2PeriphClockCmd(DEBUG_USART_CLK, ENABLE); /* Connect PXx to USARTx_Tx*/ GPIO_PinAFConfig(DEBUG_USART_RX_GPIO_PORT,DEBUG_USART_RX_SOURCE, DEBUG_USART_RX_AF); /* Connect PXx to USARTx_Rx*/ GPIO_PinAFConfig(DEBUG_USART_TX_GPIO_PORT,DEBUG_USART_TX_SOURCE,DEBUG_USART_TX_AF); /* Configure USART Tx as alternate function */ GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Pin = DEBUG_USART_TX_PIN ; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(DEBUG_USART_TX_GPIO_PORT, &GPIO_InitStructure); /* Configure USART Rx as alternate function */ GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Pin = DEBUG_USART_RX_PIN; GPIO_Init(DEBUG_USART_RX_GPIO_PORT, &GPIO_InitStructure); /* USART mode config */ USART_InitStructure.USART_BaudRate = DEBUG_USART_BAUDRATE; USART_InitStructure.USART_WordLength = USART_WordLength_8b; USART_InitStructure.USART_StopBits = USART_StopBits_1; USART_InitStructure.USART_Parity = USART_Parity_No ; USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; USART_Init(DEBUG_USART, &USART_InitStructure); USART_Cmd(DEBUG_USART, ENABLE); } ///重定向C库函数printf到USART1 int fputc(int ch, FILE *f) { /* 发送一个字节数据到USART1 */ USART_SendData(DEBUG_USART, (uint8_t) ch); /* 等待发送完毕 */ while (USART_GetFlagStatus(DEBUG_USART, USART_FLAG_TXE) == RESET); return (ch); } ///重定向C库函数scanf到USART1 int fgetc(FILE *f) { /* 等待串口输入数据 */ while (USART_GetFlagStatus(DEBUG_USART, USART_FLAG_RXNE) == RESET); return (int)USART_ReceiveData(DEBUG_USART); } /** * @brief USART1 TX DMA 配置,内存到外设(USART1->DR) */ void USART_DMA_Config(void) { DMA_InitTypeDef DMA_InitStructure; /*开启DMA时钟*/ RCC_AHB1PeriphClockCmd(DEBUG_USART_DMA_CLK, ENABLE); /* 复位初始化DMA数据流 */ DMA_DeInit(DEBUG_USART_DMA_STREAM); /* 确保DMA数据流复位完成 */ while (DMA_GetCmdStatus(DEBUG_USART_DMA_STREAM) != DISABLE) { } /*USART tx对应DMA2,通道4,数据流7*/ DMA_InitStructure.DMA_Channel = DEBUG_USART_DMA_CHANNEL; /*设置DMA源,串口数据寄存器地址*/ DMA_InitStructure.DMA_PeripheralBaseAddr = DEBUG_USART_DR_BASE; /*内存地址(要传输的变量的指针)*/ DMA_InitStructure.DMA_Memory0BaseAddr = (u32)SendBuff; /*方向:内存到外设*/ DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral; /*传输大小DMA_BufferSize=SENDBUFF_SIZE*/ DMA_InitStructure.DMA_BufferSize = SENDBUFF_SIZE; /*外设地址不增*/ DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; /*内存地址自增*/ DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; /*外设数据单位*/ DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; /*内存数据单位 8bit*/ DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; /*DMA模式:循环*/ DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; /*优先级:中*/ DMA_InitStructure.DMA_Priority = DMA_Priority_Medium; /*禁用FIFO*/ DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable; DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full; /*存储器突发传输16个节拍*/ DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single; /*外设突发传输1个节拍*/ DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single; /*配置DMA2的数据流7*/ DMA_Init(DEBUG_USART_DMA_STREAM, &DMA_InitStructure); /*使能DMA*/ DMA_Cmd(DEBUG_USART_DMA_STREAM, ENABLE); /*等待DMA数据流有效*/ while(DMA_GetCmdStatus(DEBUG_USART_DMA_STREAM) != ENABLE) { } } /*********************************************END OF FILE**********************/