片选信号不接，仍然可以收到数据

发表于 2019-12-13 23:27

stm32F407做spi从机，片选信号不接，仍然可以收到数据

发表于 2019-12-13 23:30

楼主详细说说怎么回事啊，这么说太笼统了

发表于 2019-12-13 23:33

用stm32f407做spi的从机，片选NSS设置为硬件模式，可是NSS硬件上没有接，仍然可以收到主机发来的数据

发表于 2019-12-13 23:36

程序可以公开吗？贴程序看下吧，这么说看不出什么原因

发表于 2019-12-13 23:38

      GPIO_InitTypeDef GPIO_uInitStructure;
      SPI_InitTypeDef SPI_InitStructure;
      NVIC_InitTypeDef  NVIC_InitStructure;

      RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE);
      RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1,ENABLE);
      GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_SPI1);
      GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_SPI1);
      GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_SPI1);

      GPIO_uInitStructure.GPIO_Pin = GPIO_Pin_2;
      GPIO_uInitStructure.GPIO_Mode = GPIO_Mode_OUT;
      GPIO_uInitStructure.GPIO_OType = GPIO_OType_PP;
      GPIO_uInitStructure.GPIO_PuPd = GPIO_PuPd_UP;;
      GPIO_uInitStructure.GPIO_Speed = GPIO_Speed_100MHz;
      GPIO_Init(GPIOA,&GPIO_uInitStructure);
//       SPI1_RES_ON;

      GPIO_uInitStructure.GPIO_Pin = GPIO_Pin_4;
      GPIO_uInitStructure.GPIO_Mode = GPIO_Mode_IN;
      GPIO_uInitStructure.GPIO_OType = GPIO_OType_PP;
      GPIO_uInitStructure.GPIO_PuPd = GPIO_PuPd_UP;;
      GPIO_uInitStructure.GPIO_Speed = GPIO_Speed_100MHz;  // 2M

      GPIO_Init(GPIOA,&GPIO_uInitStructure);
      //SPI1_CS_ON;

      GPIO_uInitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6|GPIO_Pin_7;
      GPIO_uInitStructure.GPIO_Mode = GPIO_Mode_AF;
      GPIO_uInitStructure.GPIO_Speed = GPIO_Speed_100MHz;
      GPIO_uInitStructure.GPIO_OType = GPIO_OType_PP;
      GPIO_uInitStructure.GPIO_PuPd = GPIO_PuPd_UP;;
      GPIO_Init(GPIOA,&GPIO_uInitStructure);

      SPI_Cmd(SPI1,DISABLE);

      SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex ;
      SPI_InitStructure.SPI_Mode = SPI_Mode_Slave;
      SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
      SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
      SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
      SPI_InitStructure.SPI_NSS = SPI_NSS_Hard;
      SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_16;             //SPI_BaudRatePrescaler_32;
      SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
      SPI_InitStructure.SPI_CRCPolynomial = 7;
      SPI_Init(SPI1,&SPI_InitStructure);

      SPI_I2S_ITConfig(SPI1, SPI_I2S_IT_RXNE, ENABLE);

      SPI_Cmd(SPI1, ENABLE);

      SPI_I2S_ClearITPendingBit(SPI1, SPI_I2S_IT_RXNE);

      NVIC_InitStructure.NVIC_IRQChannel = SPI1_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
  dma_spi1_init();

      DMA_ITConfig(DMA2_Stream5, DMA_IT_TC, ENABLE);

      NVIC_InitStructure.NVIC_IRQChannel = DMA2_Stream5_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

发表于 2019-12-13 23:41

不接可能状态是一直在片选。所以能操作

发表于 2019-12-13 23:45

你用cubeMX配置试试看。没有片选怎么还可以，搞笑呢，另外是不是悬空了，你别悬空，接地看看，不信还能收到。

发表于 2019-12-13 23:48

我们拿L0 用8bit凑出24位片选用IO口控制的

发表于 2019-12-13 23:51

功能实现了用SPI配置了LMK时钟芯片

发表于 2020-1-8 16:44

那是不是没有用到这根线啊

发表于 2020-1-8 16:46

根本就不是这个模式吧

发表于 2020-1-8 16:51

你的问题好奇怪

[STM32F4] 片选信号不接，仍然可以收到数据

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