一、DMA 简介
DMA(Direct Memory Access)—直接存储器存取，是单片机的一个外设，它的主要功能是用来搬数据，但是不需要占用 CPU，即在传输数据的时候，CPU 可以干其他的事情，好像是多线程一样。
数据传输支持从外设到存储器或者存储器到存储器，这里的存储器可以是 SRAM 或者是 FLASH。
DMA 控制器包含了 DMA1 和 DMA2，其中 DMA1 有 7 个通道，DMA2 有 5 个通道，这里的通道可以理解为传输数据的一种管道。要注意的是 DMA2 只存在于大容量的单片机中。
二、DMA 功能框图
DMA 控制器独立于内核，属于一个单独的外设，结构比较简单，从编程的角度来看，我们只需掌握功能框图中的三部分内容即可，具体见下图：
- ①DMA 请求
如果外设要想通过 DMA 来传输数据，必须先给 DMA 控制器发送 DMA 请求，DMA收到请求信号之后，控制器会给外设一个应答信号，当外设应答后且 DMA 控制器收到应答信号之后，就会启动 DMA 的传输，直到传输完毕。
DMA 有 DMA1 和 DMA2 两个控制器，DMA1 有 7 个通道，DMA2 有 5 个通道，不同的 DMA 控制器的通道对应着不同的外设请求，这决定了我们在软件编程上该怎么设置，具体见 DMA 请求映像表。
-
②通道
DMA 具有 12 个独立可编程的通道，其中 DMA1 有 7 个通道，DMA2 有 5 个通道，每个通道对应不同的外设的 DMA 请求。虽然每个通道可以接收多个外设的请求，但是同一时间只能接收一个，不能同时接收多个。 -
③仲裁器
当发生多个 DMA 通道请求时，就意味着有先后响应处理的顺序问题，这个就由仲裁器也管理。仲裁器管理 DMA 通道请求分为两个阶段。第一阶段属于软件阶段，可以在DMA_CCRx 寄存器中设置，有 4 个等级：非常高、高、中和低四个优先级。第二阶段属于硬件阶段，如果两个或以上的 DMA 通道请求设置的优先级一样，则他们优先级取决于通 道编号，编号越低优先权越高，比如通道 0 高于通道 1。在大容量产品和互联型产品中，
DMA1 控制器拥有高于 DMA2 控制器的优先级。
三、设计实例
本示例使用串口1打印并接收电脑端发来的指令，串口3作为与4G通信的渠道。
bsp_usart.h
#ifndef __USART_H
#define __USART_H
#include "stm32f10x.h"
#include <stdio.h>
// 串口1-USART1
#define DEBUG_USARTx USART1
#define DEBUG_USART_CLK RCC_APB2Periph_USART1
#define DEBUG_USART_APBxClkCmd RCC_APB2PeriphClockCmd
#define DEBUG_USART_BAUDRATE 115200
// USART GPIO 引脚宏定义
#define DEBUG_USART_GPIO_CLK (RCC_APB2Periph_GPIOA)
#define DEBUG_USART_GPIO_APBxClkCmd RCC_APB2PeriphClockCmd
#define DEBUG_USART_TX_GPIO_PORT GPIOA
#define DEBUG_USART_TX_GPIO_PIN GPIO_Pin_9
#define DEBUG_USART_RX_GPIO_PORT GPIOA
#define DEBUG_USART_RX_GPIO_PIN GPIO_Pin_10
#define DEBUG_USART_IRQ USART1_IRQn
#define DEBUG_USART_IRQHandler USART1_IRQHandler
// 串口2-USART2
//#define DEBUG_USARTx USART2
//#define DEBUG_USART_CLK RCC_APB1Periph_USART2
//#define DEBUG_USART_APBxClkCmd RCC_APB1PeriphClockCmd
//#define DEBUG_USART_BAUDRATE 115200
USART GPIO 引脚宏定义
//#define DEBUG_USART_GPIO_CLK (RCC_APB2Periph_GPIOA)
//#define DEBUG_USART_GPIO_APBxClkCmd RCC_APB2PeriphClockCmd
//
//#define DEBUG_USART_TX_GPIO_PORT GPIOA
//#define DEBUG_USART_TX_GPIO_PIN GPIO_Pin_2
//#define DEBUG_USART_RX_GPIO_PORT GPIOA
//#define DEBUG_USART_RX_GPIO_PIN GPIO_Pin_3
//#define DEBUG_USART_IRQ USART2_IRQn
//#define DEBUG_USART_IRQHandler USART2_IRQHandler
// 串口3-USART3
#define LTE_USARTx USART3
#define LTE_USART_CLK RCC_APB1Periph_USART3
#define LTE_USART_APBxClkCmd RCC_APB1PeriphClockCmd
#define LTE_USART_BAUDRATE 115200
// USART GPIO 引脚宏定义
#define LTE_USART_GPIO_CLK (RCC_APB2Periph_GPIOB)
#define LTE_USART_GPIO_APBxClkCmd RCC_APB2PeriphClockCmd
#define LTE_USART_TX_GPIO_PORT GPIOB
#define LTE_USART_TX_GPIO_PIN GPIO_Pin_10
#define LTE_USART_RX_GPIO_PORT GPIOB
#define LTE_USART_RX_GPIO_PIN GPIO_Pin_11
#define LTE_USART_IRQ USART3_IRQn
#define LTE_USART_IRQHandler USART3_IRQHandler
// 串口4-UART4
//#define DEBUG_USARTx UART4
//#define DEBUG_USART_CLK RCC_APB1Periph_UART4
//#define DEBUG_USART_APBxClkCmd RCC_APB1PeriphClockCmd
//#define DEBUG_USART_BAUDRATE 115200
USART GPIO 引脚宏定义
//#define DEBUG_USART_GPIO_CLK (RCC_APB2Periph_GPIOC)
//#define DEBUG_USART_GPIO_APBxClkCmd RCC_APB2PeriphClockCmd
//
//#define DEBUG_USART_TX_GPIO_PORT GPIOC
//#define DEBUG_USART_TX_GPIO_PIN GPIO_Pin_10
//#define DEBUG_USART_RX_GPIO_PORT GPIOC
//#define DEBUG_USART_RX_GPIO_PIN GPIO_Pin_11
//#define DEBUG_USART_IRQ UART4_IRQn
//#define DEBUG_USART_IRQHandler UART4_IRQHandler
// 串口5-UART5
//#define DEBUG_USARTx UART5
//#define DEBUG_USART_CLK RCC_APB1Periph_UART5
//#define DEBUG_USART_APBxClkCmd RCC_APB1PeriphClockCmd
//#define DEBUG_USART_BAUDRATE 115200
USART GPIO 引脚宏定义
//#define DEBUG_USART_GPIO_CLK (RCC_APB2Periph_GPIOC|RCC_APB2Periph_GPIOD)
//#define DEBUG_USART_GPIO_APBxClkCmd RCC_APB2PeriphClockCmd
//
//#define DEBUG_USART_TX_GPIO_PORT GPIOC
//#define DEBUG_USART_TX_GPIO_PIN GPIO_Pin_12
//#define DEBUG_USART_RX_GPIO_PORT GPIOD
//#define DEBUG_USART_RX_GPIO_PIN GPIO_Pin_2
//#define DEBUG_USART_IRQ UART5_IRQn
//#define DEBUG_USART_IRQHandler UART5_IRQHandler
void USART_Config(void);
void Usart_SendByte( USART_TypeDef * pUSARTx, uint8_t ch);
void Usart_SendString( USART_TypeDef * pUSARTx, char *str);
void Usart_SendHalfWord( USART_TypeDef * pUSARTx, uint16_t ch);
#endif
bsp_usart.c
#include "bsp_usart.h"
#include "bsp_dma.h"
#include "stm32f10x.h"
static void NVIC_Configuration(void);
void USART_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
// 打开串口GPIO的时钟
DEBUG_USART_GPIO_APBxClkCmd(DEBUG_USART_GPIO_CLK, ENABLE);
LTE_USART_GPIO_APBxClkCmd(LTE_USART_GPIO_CLK, ENABLE);
// 打开串口外设的时钟
DEBUG_USART_APBxClkCmd(DEBUG_USART_CLK, ENABLE);
LTE_USART_APBxClkCmd(LTE_USART_CLK, ENABLE);
// 将USART Tx的GPIO配置为推挽复用模式
GPIO_InitStructure.GPIO_Pin = DEBUG_USART_TX_GPIO_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(DEBUG_USART_TX_GPIO_PORT, &GPIO_InitStructure);
// 将USART Rx的GPIO配置为浮空输入模式
GPIO_InitStructure.GPIO_Pin = DEBUG_USART_RX_GPIO_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(DEBUG_USART_RX_GPIO_PORT, &GPIO_InitStructure);
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_USARTx, &USART_InitStructure);
GPIO_InitStructure.GPIO_Pin = LTE_USART_TX_GPIO_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(LTE_USART_TX_GPIO_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = LTE_USART_RX_GPIO_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(LTE_USART_RX_GPIO_PORT, &GPIO_InitStructure);
USART_InitStructure.USART_BaudRate = 115200;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;//8位数据
USART_InitStructure.USART_StopBits = USART_StopBits_1;//1位停止位
USART_InitStructure.USART_Parity = USART_Parity_No;//无校验
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; //硬件流控制失能
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //发送和接受使能
USART_Init(LTE_USARTx, &USART_InitStructure);
// 串口中断优先级配置
NVIC_Configuration();
// 使能串口接收中断
USART_ITConfig(DEBUG_USARTx, USART_IT_IDLE, ENABLE);
USART_ITConfig(LTE_USARTx, USART_IT_IDLE, ENABLE);
// 使能串口
USART_Cmd(DEBUG_USARTx, ENABLE);
USART_Cmd(LTE_USARTx, ENABLE);
USART_DMACmd(USART1,USART_DMAReq_Tx,ENABLE); //使能串口1的DMA发送
USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE); //使能串口1的DMA接收
USART_DMACmd(USART3,USART_DMAReq_Tx,ENABLE); //使能串口1的DMA发送
USART_DMACmd(USART3,USART_DMAReq_Rx,ENABLE); //使能串口1的DMA接收
}
void Usart_SendByte( USART_TypeDef * pUSARTx, uint8_t ch)
{
USART_SendData(pUSARTx,ch);
while (USART_GetFlagStatus(pUSARTx, USART_FLAG_TXE) == RESET);
}
void Usart_SendArray( USART_TypeDef * pUSARTx, uint8_t *array, uint16_t num)
{
uint8_t i;
for(i=0; i<num; i++)
{
Usart_SendByte(pUSARTx,array[i]);
}
while(USART_GetFlagStatus(pUSARTx,USART_FLAG_TC)==RESET);
}
void Usart_SendString( USART_TypeDef * pUSARTx, char *str)
{
unsigned int k=0;
do
{
Usart_SendByte( pUSARTx, *(str + k) );
k++;
} while(*(str + k)!='\0');
while(USART_GetFlagStatus(pUSARTx,USART_FLAG_TC)==RESET)
{ }
}
void Usart_SendHalfWord( USART_TypeDef * pUSARTx, uint16_t ch)
{
uint8_t temp_h, temp_l;
temp_h = (ch&0xFF00)>>8;
temp_l = ch&0xFF;
USART_SendData(pUSARTx,temp_h);
while (USART_GetFlagStatus(pUSARTx, USART_FLAG_TXE) == RESET);
USART_SendData(pUSARTx,temp_l);
while (USART_GetFlagStatus(pUSARTx, USART_FLAG_TXE) == RESET);
}
int fputc(int ch, FILE *f)
{
USART_SendData(DEBUG_USARTx, (uint8_t) ch);
while (USART_GetFlagStatus(DEBUG_USARTx, USART_FLAG_TXE) == RESET);
return (ch);
}
int fgetc(FILE *f)
{
while (USART_GetFlagStatus(DEBUG_USARTx, USART_FLAG_RXNE) == RESET);
return (int)USART_ReceiveData(DEBUG_USARTx);
}
void USART1_IRQHandler(void)
{
uint16_t data;
if(USART_GetITStatus(USART1,USART_IT_IDLE) != RESET)
{
DMA_Cmd(DMA1_Channel5, DISABLE); //关闭DMA,防止处理其间有数据
data = USART1->SR;
data = USART1->DR;
g_uart1ReceiveSize =RECEIVE_BUF_SIZE - DMA_GetCurrDataCounter(DMA1_Channel5);
if(g_uart1ReceiveSize !=0)
{
// OSSemPost(DMAReceiveSize_Sem);
printf("shoudao1:%s", g_uart1ReceiveBuff);
}
DMA_ClearFlag(DMA1_FLAG_TC5 | DMA1_FLAG_TE5 | DMA1_FLAG_HT5);//清除DMA2_Steam7传输完成标志
DMA_SetCurrDataCounter(DMA1_Channel5, RECEIVE_BUF_SIZE);
DMA_Cmd(DMA1_Channel5, ENABLE); //打开DMA,
}
}
void USART3_IRQHandler(void)
{
uint16_t data;
if(USART_GetITStatus(USART3,USART_IT_IDLE) != RESET)
{
DMA_Cmd(DMA1_Channel3, DISABLE); //关闭DMA,防止处理其间有数据
data = USART3->SR;
data = USART3->DR;
g_uart3ReceiveSize =RECEIVE_BUF_SIZE - DMA_GetCurrDataCounter(DMA1_Channel3);
if(g_uart3ReceiveSize !=0)
{
// OSSemPost(DMAReceiveSize_Sem);
printf("shoudao3:%s", g_uart3ReceiveBuff);
}
DMA_ClearFlag(DMA1_FLAG_TC3 | DMA1_FLAG_TE3 | DMA1_FLAG_HT3);//清除DMA2_Steam7传输完成标志
DMA_SetCurrDataCounter(DMA1_Channel3, RECEIVE_BUF_SIZE);
DMA_Cmd(DMA1_Channel3, ENABLE); //打开DMA,
}
}
static void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
NVIC_InitStructure.NVIC_IRQChannel = LTE_USART_IRQ;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = DEBUG_USART_IRQ;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
bsp_dma.h
#ifndef __DMA_H
#define __DMA_H
#include "stm32f10x.h"
#define RECEIVE_BUF_SIZE 255
#define SEND_BUF_SIZE 255
extern uint8_t g_uart1ReceiveBuff[RECEIVE_BUF_SIZE]; //接收缓冲
extern uint8_t g_uart1SendBuff[SEND_BUF_SIZE]; //发送数据缓冲区
extern uint16_t g_uart1ReceiveSize;
extern uint8_t g_uart3ReceiveBuff[RECEIVE_BUF_SIZE]; //接收缓冲
extern uint8_t g_uart3SendBuff[SEND_BUF_SIZE]; //发送数据缓冲区
extern uint16_t g_uart3ReceiveSize;
void DMA_Config(void);
void DmaSendDataProc(DMA_Channel_TypeDef *DMA_Streamx,uint16_t ndtr);
void Uart1DmaSendByte(uint8_t nSendInfo);
void Uart1DmaSendString(uint8_t* pSendInfo, uint16_t nSendCount);
void Uart3DmaSendByte(uint8_t nSendInfo);
void Uart3DmaSendString(uint8_t* pSendInfo, uint16_t nSendCount);
#endif
bsp_dma.c
#include "bsp_dma.h"
#include <stdio.h>
static void NVIC_Configuration(void);
uint8_t g_uart1ReceiveBuff[RECEIVE_BUF_SIZE]; //接收缓冲
uint8_t g_uart1SendBuff[SEND_BUF_SIZE]; //发送数据缓冲区
uint16_t g_uart1ReceiveSize = 0;
uint8_t g_uart3ReceiveBuff[RECEIVE_BUF_SIZE]; //接收缓冲
uint8_t g_uart3SendBuff[SEND_BUF_SIZE]; //发送数据缓冲区
uint16_t g_uart3ReceiveSize = 0;
void DMA_Config(void)
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); //使能DMA传输
DMA_DeInit(DMA1_Channel4);
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&USART1->DR;//DMA外设地址
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)g_uart1SendBuff;//DMA 存储器0地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;//存储器到外设模式
DMA_InitStructure.DMA_BufferSize = SEND_BUF_SIZE;//数据传输量
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//外设非增量模式
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//存储器增量模式
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;//外设数据长度:8位
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;//存储器数据长度:8位
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;// 使用普通模式
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;//中等优先级
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; //DMA通道x没有设置为内存到内存传输
DMA_Init(DMA1_Channel4, &DMA_InitStructure);//初始化DMA Stream
DMA_ITConfig(DMA1_Channel4,DMA_IT_TC,ENABLE);
DMA_DeInit(DMA1_Channel5);
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&USART1->DR;//DMA外设地址
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)g_uart1ReceiveBuff;//DMA 存储器0地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC ;//外设到存储器模式
DMA_InitStructure.DMA_BufferSize = RECEIVE_BUF_SIZE;//数据传输量
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//外设非增量模式
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//存储器增量模式
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;//外设数据长度:8位
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;//存储器数据长度:8位
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;// 使用普通模式
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;//中等优先级
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; //DMA通道x没有设置为内存到内存传输
DMA_Init(DMA1_Channel5, &DMA_InitStructure);//初始化DMA Stream
DMA_DeInit(DMA1_Channel2);
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&USART3->DR;//DMA外设地址
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)g_uart3SendBuff;//DMA 存储器0地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;//存储器到外设模式
DMA_InitStructure.DMA_BufferSize = SEND_BUF_SIZE;//数据传输量
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//外设非增量模式
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//存储器增量模式
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;//外设数据长度:8位
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;//存储器数据长度:8位
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;// 使用普通模式
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;//中等优先级
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; //DMA通道x没有设置为内存到内存传输
DMA_Init(DMA1_Channel2, &DMA_InitStructure);//初始化DMA Stream
DMA_ITConfig(DMA1_Channel2,DMA_IT_TC,ENABLE);
DMA_DeInit(DMA1_Channel3);
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&USART3->DR;//DMA外设地址
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)g_uart3ReceiveBuff;//DMA 存储器0地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC ;//外设到存储器模式
DMA_InitStructure.DMA_BufferSize = RECEIVE_BUF_SIZE;//数据传输量
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//外设非增量模式
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//存储器增量模式
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;//外设数据长度:8位
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;//存储器数据长度:8位
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;// 使用普通模式
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;//中等优先级
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; //DMA通道x没有设置为内存到内存传输
DMA_Init(DMA1_Channel3, &DMA_InitStructure);//初始化DMA Stream
NVIC_Configuration();
DMA_Cmd(DMA1_Channel5, ENABLE); //开启DMA传输
DMA_Cmd(DMA1_Channel3, ENABLE); //开启DMA传输
DMA_ITConfig(DMA1_Channel5,DMA_IT_TC,ENABLE);
DMA_ITConfig(DMA1_Channel3,DMA_IT_TC,ENABLE);
}
void DmaSendDataProc(DMA_Channel_TypeDef *DMA_Streamx,uint16_t ndtr)
{
DMA_Cmd(DMA_Streamx, DISABLE); //关闭DMA传输
DMA_SetCurrDataCounter(DMA_Streamx,ndtr); //数据传输量
DMA_Cmd(DMA_Streamx, ENABLE); //开启DMA传输
}
void Uart1DmaSendByte(uint8_t nSendInfo)
{
uint8_t *pBuf = NULL;
//指向发送缓冲区
pBuf = g_uart1SendBuff;
*pBuf++ = nSendInfo;
DmaSendDataProc(DMA1_Channel4, 1); //开始一次DMA传输！
}
void Uart1DmaSendString(uint8_t* pSendInfo, uint16_t nSendCount)
{
uint16_t i = 0;
uint8_t *pBuf = NULL;
//指向发送缓冲区
pBuf = g_uart1SendBuff;
for (i=0; i<nSendCount; i++)
{
*pBuf++ = pSendInfo[i];
}
//DMA发送方式
DmaSendDataProc(DMA1_Channel4, nSendCount); //开始一次DMA传输！
}
void Uart3DmaSendByte(uint8_t nSendInfo)
{
uint8_t *pBuf = NULL;
//指向发送缓冲区
pBuf = g_uart3SendBuff;
*pBuf++ = nSendInfo;
DmaSendDataProc(DMA1_Channel2, 1); //开始一次DMA传输！
}
void Uart3DmaSendString(uint8_t* pSendInfo, uint16_t nSendCount)
{
uint16_t i = 0;
uint8_t *pBuf = NULL;
//指向发送缓冲区
pBuf = g_uart3SendBuff;
for (i=0; i<nSendCount; i++)
{
*pBuf++ = pSendInfo[i];
}
//DMA发送方式
DmaSendDataProc(DMA1_Channel2, nSendCount); //开始一次DMA传输！
}
void DMA1_Channel4_IRQHandler(void)
{
//清除标志
if(DMA_GetFlagStatus(DMA1_FLAG_TC4)!=RESET)//等待传输完成
{
DMA_ClearFlag(DMA1_FLAG_TC4);//清除传输完成标志
}
}
void DMA1_Channel5_IRQHandler(void)
{
//清除标志
if(DMA_GetFlagStatus(DMA1_FLAG_TC5)!=RESET)//等待传输完成
{
DMA_Cmd(DMA1_Channel5, DISABLE); //关闭DMA,防止处理其间有数据
g_uart1ReceiveSize =RECEIVE_BUF_SIZE - DMA_GetCurrDataCounter(DMA1_Channel5);
if(g_uart1ReceiveSize !=0)
{
// 此处不处理数据，uart处理
}
DMA_ClearFlag(DMA1_FLAG_TC5 | DMA1_FLAG_TE5 | DMA1_FLAG_HT5);//清除DMA2_Steam7传输完成标志
DMA_SetCurrDataCounter(DMA1_Channel5, RECEIVE_BUF_SIZE);
DMA_Cmd(DMA1_Channel5, ENABLE); //打开DMA,
}
}
void DMA1_Channel2_IRQHandler(void)
{
//清除标志
if(DMA_GetFlagStatus(DMA1_FLAG_TC2)!=RESET)//等待传输完成
{
DMA_ClearFlag(DMA1_FLAG_TC2);//清除传输完成标志
}
}
void DMA1_Channel3_IRQHandler(void)
{
//清除标志
if(DMA_GetFlagStatus(DMA1_FLAG_TC3)!=RESET)//等待传输完成
{
DMA_Cmd(DMA1_Channel3, DISABLE); //关闭DMA,防止处理其间有数据
g_uart3ReceiveSize =RECEIVE_BUF_SIZE - DMA_GetCurrDataCounter(DMA1_Channel3);
if(g_uart3ReceiveSize !=0)
{
// 此处不处理数据，uart处理
}
DMA_ClearFlag(DMA1_FLAG_TC3 | DMA1_FLAG_TE3 | DMA1_FLAG_HT3);//清除DMA2_Steam7传输完成标志
DMA_SetCurrDataCounter(DMA1_Channel3, RECEIVE_BUF_SIZE);
DMA_Cmd(DMA1_Channel3, ENABLE); //打开DMA,
}
}
static void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);
// 配置UART1发送
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
// 配置UART1接收
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
// 配置UART3发送
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
// 配置UART3接收
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 4;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
main.c
int main()
{
...
USART_Config();
DMA_Config();
...
}
• 由 青梅煮久 写于 2021 年 02 月 20 日
