STM32F103的W25Q64的DMA高效数据访问实现

1. 关于DMA

首先任何FLASH的写操作都是非常耗时的,体现在擦除FLASH上,且写操作不能太频繁,故而用DMA方式实现写操作程序逻辑会非常复杂,程序逻辑在各种中断处理中容易乱,与之相反采用DMA读大批量数据时及具有优势. 比如36MHzSPI时种,采用轮询方式读一页数据需要花费250us时间,二用了DMA后只需要80us时间,提高了三倍还多,且启动DMA只需要5us,节省了245us时间.

2. W25Q64实用的函数

① 读ID号,用于确定芯片是否能正常访问 ② 轮询方式读数据 ③ 擦除指令 ④ 写一页数据指令,(事先要擦除) ⑤ DMA方式读取一块数据

3. 程序正文W25Q64.c

[cpp] view plain copy

#include "w25q64.h"
uint8_t W25X_Buffer[W25X_SECTOR_SIZE];
volatile bool sem_W25X_DMA_Busy = true;
volatile bool sem_W25X_DMA_RxRdy= false;
static uint8_t W25X_TX_Byte=0xFF;
void W25X_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5|GPIO_Pin_6|GPIO_Pin_7;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStruct);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOB, ENABLE);
W25X_WP_EN();
W25X_CS_H();
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStruct);
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStruct);
GPIO_PinLockConfig(GPIOA,GPIO_Pin_4);
GPIO_PinLockConfig(GPIOB,GPIO_Pin_0);
}
void W25X_Init(void)
{
SPI_InitTypeDef SPI_InitStructure ;
DMA_InitTypeDef DMA_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
//配置DMA通道,DMA1_CH2收
//读取SPI FLASH时多数为空数据故而数据地址无需增加
//启动DMA1的时钟
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
DMA_DeInit(DMA1_Channel2);
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&SPI1->DR);
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)W25X_Buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize = 0;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel2, &DMA_InitStructure);
//配置DMA通道,DMA1_CH3发送
DMA_DeInit(DMA1_Channel3);
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&SPI1->DR);
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)(&W25X_TX_Byte);
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
DMA_InitStructure.DMA_BufferSize = 0;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel3, &DMA_InitStructure);
//关闭DMA,清DMA标记,使能DMA1_CH2的传输完成中断
DMA_Cmd(DMA1_Channel3, DISABLE); //关闭发送DMA
DMA_Cmd(DMA1_Channel2, DISABLE); //关闭接收DMA
DMA_ClearFlag(DMA1_FLAG_GL3|DMA1_FLAG_TC3|DMA1_FLAG_HT3|DMA1_FLAG_TE3);
DMA_ClearFlag(DMA1_FLAG_GL2|DMA1_FLAG_TC2|DMA1_FLAG_HT2|DMA1_FLAG_TE2);
DMA_ITConfig(DMA1_Channel2,DMA_IT_TC,ENABLE);
//初始化SPI时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1,ENABLE);
// SPI配置
SPI_Cmd(SPI1,DISABLE);
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex ;
SPI_InitStructure.SPI_Mode = SPI_Mode_Master ;
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b ;
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low ;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge ;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft ;
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_2 ; //72MHz分频
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB ; //SPI设置成LSB模式
SPI_InitStructure.SPI_CRCPolynomial = 7 ;
SPI_Init( SPI1, &SPI_InitStructure ) ;
SPI_Cmd(SPI1,ENABLE); //启动SPI
//打开SPI1的DMA发送接收请求
SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Rx, ENABLE);
SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Tx, ENABLE);
//清DMA忙信号
sem_W25X_DMA_Busy = false;
//使能NVIC中断
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = W25X_DMA_TC_PRIO;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
uint8_t W25X_ReadWriteByte(uint8_t dat)
{
while ((SPI1->SR & SPI_I2S_FLAG_TXE) == (uint16_t)RESET);
SPI1->DR = dat;
while ((SPI1->SR & SPI_I2S_FLAG_RXNE) == (uint16_t)RESET);
return (SPI1->DR);
}
uint8_t W25X_ReadSR(void)
{
uint8_t byte=0;
W25X_CS_L(); //使能器件
W25X_ReadWriteByte(W25X_ReadStatusReg); //发送读取状态寄存器命令
byte=W25X_ReadWriteByte(0Xff); //读取一个字节
W25X_CS_H(); //使能器件
return byte;
}
uint16_t W25X_ReadID(void)
{
uint16_t Temp = 0;
W25X_CS_L();
W25X_ReadWriteByte(0x90); //发送读取ID命令
W25X_ReadWriteByte(0x00);
W25X_ReadWriteByte(0x00);
W25X_ReadWriteByte(0x00);
Temp|=W25X_ReadWriteByte(0xFF)<<8;
Temp|=W25X_ReadWriteByte(0xFF);
W25X_CS_H();
return Temp;
}
void W25X_Wait_Busy(void)
{
while((W25X_ReadSR()&0x01)==0x01); // 等待BUSY位清空
}
bool W25X_Read_BusyState(void)
{
if((W25X_ReadSR()&0x01))return true;
else return false;
}
void W25X_Write_Enable(void)
{
W25X_WP_EN(); //打开硬件写使能
W25X_CS_L(); //使能器件
W25X_ReadWriteByte(W25X_WriteEnable); //发送写使能
W25X_CS_H(); //取消片选
}
void W25X_Write_Disable(void)
{
W25X_WP_DIS(); //关闭硬件写使能
W25X_CS_L(); //使能器件
W25X_ReadWriteByte(W25X_WriteDisable); //发送写禁止指令
W25X_CS_H(); //取消片选
}
void SPI_Flash_PowerDown(void)
{
uint16_t i;
W25X_CS_L(); //使能器件
W25X_ReadWriteByte(W25X_PowerDown); //发送掉电命令
W25X_CS_H(); //取消片选
i= (72)*3;while(i--); //等待约3us
}
void SPI_Flash_WakeUp(void)
{
uint16_t i;
W25X_CS_L(); //使能器件
W25X_ReadWriteByte(W25X_ReleasePowerDown); //发送掉电命令
W25X_CS_H(); //取消片选
i= (72)*3;while(i--); //等待约3us
}
void W25X_Erase_Chip(bool bwait)
{
W25X_Write_Enable(); //SET WEL
W25X_Wait_Busy();
W25X_CS_L(); //使能器件
W25X_ReadWriteByte(W25X_ChipErase); //发送片擦除命令
W25X_CS_H(); //取消片选
if(bwait)W25X_Wait_Busy(); //等待芯片擦除结束
}
void W25X_Erase_Sector(uint32_t Dst_Addr,bool bwait)
{
W25X_Write_Enable(); //SET WEL
W25X_Wait_Busy();
W25X_CS_L(); //使能器件
W25X_ReadWriteByte(W25X_SectorErase); //发送扇区擦除指令
W25X_ReadWriteByte((uint8_t)((Dst_Addr)>>16)); //发送24bit地址
W25X_ReadWriteByte((uint8_t)((Dst_Addr)>>8));
W25X_ReadWriteByte((uint8_t)Dst_Addr);
W25X_CS_H(); //取消片选
if(bwait)W25X_Wait_Busy(); //等待擦除完成
}
void W25X_Read_Page(uint8_t * pBuffer,uint32_t PageAddr)
{
uint32_t ReadAddr;
uint16_t i;
if(PageAddr < W25X_PAGE_NUM)
{
ReadAddr = PageAddr *W25X_PAGE_SIZE;
W25X_CS_L();
W25X_ReadWriteByte(W25X_ReadData); //发送读取命令
W25X_ReadWriteByte((uint8_t)((ReadAddr)>>16)); //发送24bit地址
W25X_ReadWriteByte((uint8_t)((ReadAddr)>>8));
W25X_ReadWriteByte((uint8_t)ReadAddr);
for(i=0;i<W25X_PAGE_SIZE;i++)
{
pBuffer[i]=W25X_ReadWriteByte(0XFF); //循环读数
}
W25X_CS_H();
}
}
void W25X_Write_Page(uint8_t * pBuffer,uint32_t PageAddr)
{
uint16_t i;
uint32_t WriteAddr;
//打开写状态,并等待上次写操作完成
W25X_Write_Enable();
W25X_Wait_Busy(); //等待擦除完成
//将数据写入FLASH
WriteAddr =PageAddr* W25X_PAGE_SIZE;
W25X_CS_L();
W25X_ReadWriteByte(W25X_PageProgram); //发送写页命令
W25X_ReadWriteByte((uint8_t)((WriteAddr)>>16)); //发送24bit地址
W25X_ReadWriteByte((uint8_t)((WriteAddr)>>8));
W25X_ReadWriteByte((uint8_t)WriteAddr);
for(i=0;i<W25X_PAGE_SIZE;i++)W25X_ReadWriteByte(pBuffer[i]);//循环写数
W25X_CS_H();
//W25X_Wait_Busy(); //等待擦除完成
}
void W25X_Read_Data(uint8_t * pBuffer,uint32_t ReadAddr,uint16_t NumByteToRead)
{
uint16_t i;
W25X_CS_L();
W25X_ReadWriteByte(W25X_ReadData); //发送读取命令
W25X_ReadWriteByte((uint8_t)((ReadAddr)>>16)); //发送24bit地址
W25X_ReadWriteByte((uint8_t)((ReadAddr)>>8));
W25X_ReadWriteByte((uint8_t)ReadAddr);
for(i=0;i<NumByteToRead;i++)
{
pBuffer[i]=W25X_ReadWriteByte(0XFF); //循环读数
}
W25X_CS_H();
}
void W25X_DMARead_Data(uint8_t * pBuffer,uint32_t ReadAddr,uint16_t NumByteToRead)
{
//判断DMA是否仍处于工作状态,若是则等待传输完成,
if( (DMA1_Channel2->CCR & DMA_CCR1_EN) || (DMA1_Channel3->CCR & DMA_CCR1_EN) )
{
//while( !DMA_GetFlagStatus(DMA1_FLAG_TC2));//高效写法如下
while( !(DMA1->ISR & DMA1_FLAG_TC2)); //等待传送完成
sem_W25X_DMA_RxRdy = true; //标记DMA接收数据信号
W25X_CS_H(); //结束片选
__NOP();__NOP();__NOP();__NOP(); //短延时,使CS有足够的拉高时间
}
//设置DMA数据载荷,并清DMA标记
sem_W25X_DMA_Busy = true; //标记为DMA忙
DMA1_Channel3->CMAR = (uint32_t)(&W25X_TX_Byte); //设置发送数据的源SRAM地址
DMA1_Channel3->CNDTR= NumByteToRead; //设置发送字节长度,发送SRAM地址不增加
DMA1_Channel2->CMAR =(uint32_t)pBuffer; //设置接收数据个数
DMA1_Channel2->CNDTR= NumByteToRead; //设置接收数据的目标SRAM地址
//发送前导字节
W25X_CS_L();
W25X_ReadWriteByte(W25X_ReadData); //发送读取命令
W25X_ReadWriteByte((uint8_t)((ReadAddr)>>16)); //发送24bit地址
W25X_ReadWriteByte((uint8_t)((ReadAddr)>>8));
W25X_ReadWriteByte((uint8_t)ReadAddr);
SPI1->DR ; //接送前读一次SPI1->DR，保证接收缓冲区为空
//清DMA标记
DMA_ClearFlag(DMA1_FLAG_GL3|DMA1_FLAG_TC3|DMA1_FLAG_HT3|DMA1_FLAG_TE2);
DMA_ClearFlag(DMA1_FLAG_GL2|DMA1_FLAG_TC2|DMA1_FLAG_HT2|DMA1_FLAG_TE2);
//启动DMA发送数据
while ((SPI1->SR & SPI_I2S_FLAG_TXE) == (uint16_t)RESET);
DMA_Cmd(DMA1_Channel3, ENABLE);
DMA_Cmd(DMA1_Channel2, ENABLE);
//等待DMA传送数据完毕
}
void W25X_Read_UID(uint8_t * pBuffer)
{
uint8_t i;
W25X_CS_L();
W25X_ReadWriteByte(W25X_ReadUniqueID);
W25X_ReadWriteByte(0x00);
W25X_ReadWriteByte(0x00);
W25X_ReadWriteByte(0x00);
W25X_ReadWriteByte(0x00);
for(i=0;i<8;i++)
pBuffer[i]=W25X_ReadWriteByte(0XFF); //循环读数
W25X_CS_H();
}
void DMA1_Channel2_IRQHandler(void)
{
//空读ISR状态
DMA1->ISR;
//关闭DMA通道
//DMA_Cmd(DMA1_Channel2, DISABLE);//以下为等效写法
//DMA_Cmd(DMA1_Channel3, DISABLE);//以下为等效写法
DMA1_Channel2->CCR &= ~DMA_CCR1_EN; //关闭DMA1_CH2
DMA1_Channel3->CCR &= ~DMA_CCR1_EN; //关闭DMA1_CH2
//清DMA中断标记
//DMA_ClearITPendingBit(DMA1_IT_GL2|DMA1_IT_TC2|DMA1_IT_HT2|DMA1_IT_TE2);//以下为等待模式
DMA1->IFCR = DMA1_IT_GL2|DMA1_IT_TC2|DMA1_IT_HT2|DMA1_IT_TE2;
//置信号量
DMA_Cmd(DMA1_Channel3, DISABLE); //关闭发送DMA
DMA_Cmd(DMA1_Channel2, DISABLE); //关闭接收DMA
sem_W25X_DMA_Busy = false; //标记为DMA空闲
sem_W25X_DMA_RxRdy = true; //标记DMA接收数据信号
W25X_CS_H(); //结束片选
}

4. 头文件W25Q64.h

[cpp] view plain copy

#ifndef _W25Q64_H_
#define _W25Q64_H_
#include "stm32f10x.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_rcc.h"
#include "stm32f10x_spi.h"
#include "stm32f10x_dma.h"
#include <string.h>
#include <stdbool.h>
#include <stdint.h>
#define W25X_DMA_TC_PRIO 2
#define W25X_PAGE_SIZE 256
#define W25X_PAGE_NUM 32768
#define W25X_SECTOR_SIZE 4096
#define W25X_PAGES_PS (W25X_SECTOR_SIZE/W25X_PAGE_SIZE)
#define W25X_BUFF_NUM 2
#define W25X_DUMMY_BYTE 0xFF
#define W25X_ReadStatusReg 0x05 //读状态寄存器1
#define W25X_ReadStatusReg2 0x35 //读状态寄存器2
#define W25X_WriteStatusReg 0x01 //写状态寄存器1
#define W25X_ReadUniqueID 0x4B //读取唯一ID
#define W25X_WriteEnable 0x06 //写使能
#define W25X_WriteDisable 0x04 //写关闭
#define W25X_ReadData 0x03 //读数据
#define W25X_PageProgram 0x02 //写FLASH
#define W25X_ChipErase 0x60 //也可为0x60
#define W25X_SectorErase 0x20 //4KB擦除
#define W25X_PowerDown 0xB9 //掉电,低功耗
#define W25X_ReleasePowerDown 0xAB //恢复上电
#define W25X_WP_DIS() (GPIOB->BRR = GPIO_Pin_0)
#define W25X_WP_EN() (GPIOB->BSRR = GPIO_Pin_0)
#define W25X_CS_L() (GPIOA->BRR = GPIO_Pin_4)
#define W25X_CS_H() (GPIOA->BSRR = GPIO_Pin_4)
extern uint8_t W25X_Buffer[W25X_SECTOR_SIZE];
extern volatile bool sem_W25X_DMA_Busy; //用户只读
extern volatile bool sem_W25X_DMA_RxRdy; //用户读取,清零
//初始化
extern void W25X_GPIO_Config(void); //配置GPIO口
extern void W25X_Init(void); //初始化SPI
//获取状态
extern uint8_t W25X_ReadSR(void); //读取状态寄存器
extern uint16_t W25X_ReadID(void); //读取ID号
extern void W25X_Wait_Busy(void); //等待W25X直到空闲
extern bool W25X_Read_BusyState(void); //读取W25X的忙状态(不等待)
//控制状态
extern void W25X_Write_Enable(void); //写使能
extern void W25X_Write_Disable(void); //写禁止
extern void SPI_Flash_PowerDown(void); //掉电
extern void SPI_Flash_WakeUp(void); //唤醒
//擦除相关(有等待选择)
extern void W25X_Erase_Chip(bool bwait); //全片擦除,要等待写完成,需要21秒
extern void W25X_Erase_Sector(uint32_t Dst_Addr,bool bwait); //扇区擦除,实际需要65ms
extern void W25X_Read_Data(uint8_t * pBuffer,uint32_t ReadAddr,uint16_t NumByteToRead); //250us执行完毕
extern void W25X_DMARead_Data(uint8_t * pBuffer,uint32_t ReadAddr,uint16_t NumByteToRead); //5us执行,75us后结束
extern void W25X_Read_Page(uint8_t * pBuffer,uint32_t PageAddr); //读出一页,300us
extern void W25X_Write_Page(uint8_t * pBuffer,uint32_t PageAddr); //写入一页,必先擦除,事先有些等待,600us
extern void W25X_Read_UID(uint8_t * pBuffer); //读取W25X的唯一MAC,<5us
#endif

STM32F103访问W25Q64STM32F103的W25Q64的DMA高效数据访问实现

STM32F103的W25Q64的DMA高效数据访问实现

1. 关于DMA

2. W25Q64实用的函数

3. 程序正文W25Q64.c

4. 头文件W25Q64.h

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