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标题: stm32 华邦W25X32芯片spi总线配置 [打印本页]

作者: look_w    时间: 2017-10-24 17:57     标题: stm32 华邦W25X32芯片spi总线配置

#include "stm32f10x_gpio.h"#include "stm32f10x_spi.h" #define FLASH_CS     (1<<6)#define SPI_FLASH_CS(x)  GPIOB->ODR=(GPIOB->ODR&~FLASH_CS)|(x ? FLASH_CS:0)      //命令片选 // SPI总线速度设置#define SPI_SPEED_2 0#define SPI_SPEED_8 1#define SPI_SPEED_16 2#define SPI_SPEED_256 3  //SPI 速度设置函数//SpeedSet://SPI_SPEED_2 2分频 (SPI 36M@sys 72M)//SPI_SPEED_8 8分频 (SPI 9M@sys 72M)//SPI_SPEED_16 16分频 (SPI 4.5M@sys 72M)//SPI_SPEED_256 256分频 (SPI 281.25K@sys 72M)void SPIx_SetSpeed(u8 SpeedSet){    SPI3->CR1 &= 0XFFC7;//Fsck=Fcpu/256     if(SpeedSet == SPI_SPEED_2)  //二分频    {        SPI3->CR1 |= 0 << 3;//Fsck=Fpclk/2=36Mhz    }    else if(SpeedSet == SPI_SPEED_8)  //八分频    {        SPI3->CR1 |= 2 << 3;//Fsck=Fpclk/8=9Mhz    }    else if(SpeedSet == SPI_SPEED_16)  //十六分频    {        SPI3->CR1 |= 3 << 3;//Fsck=Fpclk/16=4.5Mhz    }    else //256分频    {        SPI3->CR1 |= 7 << 3; //Fsck=Fpclk/256=281.25Khz 低速模式    }     SPI3->CR1 |= 1 << 6; //SPI设备使能} //SPI口初始化//这里针是对SPI3的初始化 void SPIx_Init(void){    SPI_InitTypeDef   SPI_InitStructure;    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;//SPI_BaudRatePrescaler_4;    SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;    SPI_InitStructure.SPI_CRCPolynomial = 7;    SPI_Init(SPI3, &SPI_InitStructure);    SPI_Cmd(SPI3, ENABLE);    SPI3->SR |= SPI_I2S_FLAG_TXE;    SPIx_SetSpeed(SPI_SPEED_2);}




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