stm32单片机个人学习笔记16（SPI通信协议）

前言

本篇文章属于stm32单片机（以下简称单片机）的学习笔记，来源于B站教学视频。下面是这位up主的视频链接。本文为个人学习笔记，只能做参考，细节方面建议观看视频，肯定受益匪浅。

STM32入门教程-2023版 细致讲解 中文字幕_哔哩哔哩_bilibili

一、SPI通信

1.硬件电路规定 

2.移位示意图 

 3.软件时序规定

 

4.实际通信时序

区别于I2C是对寄存器进行操作，SPI通信的从机会定义一个指令集，起始条件后，主机给从机发一个指令完成相应任务即可

第一个字节为写指令0x02，第二三四个字节为地址，地址高位先行，第五个字节是写入的数据

第一个字节为写指令0x02，第二三四个字节为地址，第五个字节进行交换字节，主机发送一个0xFF或0x00把从机发送的数据交换回来

二、W25Q64

1.简介

2.硬件电路

3.W25Q64框图 

把8MB的内存分为128个块（Block），每个块又分为16个扇（Sector），每个扇又分16页（Page） ，每页256B

4.Flash操作注意事项

5.具体细节详见W25Q64的参考手册 

三、软件SPI读写W25Q64

1.MySPI.c

#include "stm32f10x.h"                  // Device headervoid MySPI_W_SS(uint8_t BitValue)
{GPIO_WriteBit(GPIOA, GPIO_Pin_4, (BitAction)BitValue);
}void MySPI_W_SCK(uint8_t BitValue)
{GPIO_WriteBit(GPIOA, GPIO_Pin_5, (BitAction)BitValue);
}void MySPI_W_MOSI(uint8_t BitValue)
{GPIO_WriteBit(GPIOA, GPIO_Pin_7, (BitAction)BitValue);
}uint8_t MySPI_R_MISO(void)
{return GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_6);
}void MySPI_Init(void)
{RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_7;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);MySPI_W_SS(1);MySPI_W_SCK(0);
}void MySPI_Start(void)
{MySPI_W_SS(0);
}void MySPI_Stop(void)
{MySPI_W_SS(1);
}uint8_t MySPI_SwapByte(uint8_t ByteSend)
{uint8_t i, ByteReceive = 0x00;for (i = 0; i < 8;i++){MySPI_W_MOSI(ByteSend & (0x80 >> i));MySPI_W_SCK(1);if (MySPI_R_MISO() == 1) {ByteReceive |= (0x80 >> i);}MySPI_W_SCK(0);}return ByteReceive;
}

其中交换字节函数还可写为

uint8_t MySPI_SwapByte(uint8_t ByteSend)
{uint8_t i;for (i = 0; i < 8;i++){MySPI_W_MOSI(ByteSend & 0x80);ByteSend <<= 1;MySPI_W_SCK(1);if (MySPI_R_MISO() == 1) {ByteSend |= 0x01;}MySPI_W_SCK(0);}return ByteSend;
}

这样效率更高，但会改变ByteSend的值

2.W25Q64.c

#include "stm32f10x.h"                  // Device header
#include "MySPI.h"
#include "W25Q64_Ins.h"void W25Q64_Init(void)
{MySPI_Init();
}void W25Q64_ReadID(uint8_t *MID, uint16_t *DID)
{MySPI_Start();MySPI_SwapByte(W25Q64_JEDEC_ID);*MID = MySPI_SwapByte(W25Q64_DUMMY_BYTE);*DID = MySPI_SwapByte(W25Q64_DUMMY_BYTE);*DID <<= 8;*DID |= MySPI_SwapByte(W25Q64_DUMMY_BYTE);MySPI_Stop();
}void W25Q64_WriteEnable(void)
{MySPI_Start();MySPI_SwapByte(W25Q64_WRITE_ENABLE);MySPI_Stop();
}void W25Q64_WaitBusy(void)
{uint32_t TimeOut = 100000;MySPI_Start();MySPI_SwapByte(W25Q64_READ_STATUS_REGISTER_1);while((MySPI_SwapByte(W25Q64_DUMMY_BYTE) & 0x01) == 0x01){TimeOut--;if (TimeOut == 0){break;}}MySPI_Stop();
}void W25Q64_PageProgram(uint32_t Address, uint8_t *DataArray, uint16_t Count)
{uint16_t i;W25Q64_WriteEnable();MySPI_Start();MySPI_SwapByte(W25Q64_PAGE_PROGRAM);MySPI_SwapByte(Address >> 16);MySPI_SwapByte(Address >> 8);MySPI_SwapByte(Address);for (i = 0;i < Count;i++){MySPI_SwapByte(DataArray[i]);}MySPI_Stop();	W25Q64_WaitBusy();
}void W25Q64_SectorErase(uint32_t Address)
{W25Q64_WriteEnable();MySPI_Start();MySPI_SwapByte(W25Q64_SECTOR_ERASE_4KB);MySPI_SwapByte(Address >> 16);MySPI_SwapByte(Address >> 8);MySPI_SwapByte(Address);MySPI_Stop();	W25Q64_WaitBusy();
}void W25Q64_ReadData(uint32_t Address, uint8_t *DataArray, uint32_t Count)
{uint32_t i;MySPI_Start();MySPI_SwapByte(W25Q64_READ_DATA);MySPI_SwapByte(Address >> 16);MySPI_SwapByte(Address >> 8);MySPI_SwapByte(Address);for (i = 0;i < Count;i++){DataArray[i] = MySPI_SwapByte(W25Q64_DUMMY_BYTE);}MySPI_Stop();	
}

3.main.c

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "W25Q64.h"uint8_t MID;
uint16_t DID;uint8_t ArrayWrite[] = {0xB1, 0xB2, 0xB3, 0xB4};
uint8_t ArrayRead[4];int main(void)
{OLED_Init();W25Q64_Init();OLED_ShowString(1, 1, "MID:   DID:");OLED_ShowString(2, 1, "W:");OLED_ShowString(3, 1, "R:");W25Q64_ReadID(&MID, &DID);OLED_ShowHexNum(1, 5, MID, 2);OLED_ShowHexNum(1, 12, DID, 4);W25Q64_SectorErase(0x000000);W25Q64_PageProgram(0x000000, ArrayWrite, 4);W25Q64_ReadData(0x000000, ArrayRead, 4);OLED_ShowHexNum(2, 3, ArrayWrite[0], 2);OLED_ShowHexNum(2, 6, ArrayWrite[1], 2);OLED_ShowHexNum(2, 9, ArrayWrite[2], 2);OLED_ShowHexNum(2, 12, ArrayWrite[3], 2);OLED_ShowHexNum(3, 3, ArrayRead[0], 2);OLED_ShowHexNum(3, 6, ArrayRead[1], 2);OLED_ShowHexNum(3, 9, ArrayRead[2], 2);OLED_ShowHexNum(3, 12, ArrayRead[3], 2);while (1){}
}

四、硬件SPI读写W25Q64

1.SPI通信外设

2.SPI框图

3.SPI基本结构

4.主模式全双工连续传输（较为复杂，性能好）

5.非连续传输（较为简单，性能差一点）

6.代码部分

只需更改MySPI.c部分的内容即可

配置好硬件SPI

#include "stm32f10x.h"                  // Device headervoid MySPI_W_SS(uint8_t BitValue)
{GPIO_WriteBit(GPIOA, GPIO_Pin_4, (BitAction)BitValue);
}void MySPI_Init(void)
{RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);SPI_InitTypeDef SPI_InitStructure;SPI_InitStructure.SPI_Mode = SPI_Mode_Master;SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_128;SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;SPI_InitStructure.SPI_CRCPolynomial = 7;SPI_Init(SPI1, &SPI_InitStructure);SPI_Cmd(SPI1, ENABLE);MySPI_W_SS(1);
}void MySPI_Start(void)
{MySPI_W_SS(0);
}void MySPI_Stop(void)
{MySPI_W_SS(1);
}uint8_t MySPI_SwapByte(uint8_t ByteSend)
{while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) != SET);SPI_I2S_SendData(SPI1, ByteSend);while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) != SET);return SPI_I2S_ReceiveData(SPI1);
}