SPI continuous transmfer problems
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2014-03-17 1:20 AM
Posted on March 17, 2014 at 09:20
Would you help me to figure out how to access the SPI correctly? Best Regards Shine Hou attached information Device: STM32F407IGIDE: KeilC source code: 1. SPI initialization { GPIO_InitTypeDef GPIO_InitStruct; SPI_InitTypeDef SPI_InitStruct; // NVIC_InitTypeDef NVIC_InitStruct; /* Peripheral Clock Enable -------------------------------------------------*/ /* Enable the SPI clock (Port B) */ RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE); /* Enable GPIO clocks (Port B) */ RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE); /* SPI GPIO Configuration --------------------------------------------------*/ /* GPIO Deinitialisation */ GPIO_DeInit(GPIOB); /* Connect SPI (SCK & MISO & MOSI) pins to AF5 */ GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_SPI2); // SPI2_SCK GPIO_PinAFConfig(GPIOB, GPIO_PinSource14, GPIO_AF_SPI2); // SPI2_MISO GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_SPI2); // SPI2_MOSI GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStruct.GPIO_OType = GPIO_OType_PP; GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_DOWN; GPIO_InitStruct.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15; GPIO_Init(GPIOB, &GPIO_InitStruct); /* SPI CS1 pin configuration */ GPIO_InitStruct.GPIO_Pin = SPI_CS_PIN; GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT; GPIO_InitStruct.GPIO_OType = GPIO_OType_PP; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP; GPIO_Init(GPIOB, &GPIO_InitStruct); GPIO_SetBits(GPIOB, GPIO_InitStruct.GPIO_Pin ); /* SPI configuration -------------------------------------------------------*/ /* SPI Deinitialisation */ SPI_I2S_DeInit(SPI2); SPI_InitStruct.SPI_Direction = SPI_Direction_2Lines_FullDuplex; SPI_InitStruct.SPI_DataSize = SPI_DataSize_8b; SPI_InitStruct.SPI_CPOL = SPI_CPOL_Low; SPI_InitStruct.SPI_CPHA = SPI_CPHA_2Edge; SPI_InitStruct.SPI_NSS = SPI_NSS_Soft; SPI_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_8; SPI_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB; SPI_InitStruct.SPI_CRCPolynomial = 7; SPI_InitStruct.SPI_Mode = SPI_Mode_Master; // Master Mode SPI_Init(SPI2, &SPI_InitStruct); SPI_Cmd(SPI2, ENABLE);}2. SPI Read GPIO_ResetBits(GPIOB, SPI_CS_PIN); while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_TXE) == RESET); SPI_I2S_SendData(SPI2, reg_addr | 0x80); for (n1=0; n1<reg_num; n1++ ) { while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_TXE) == RESET); SPI_I2S_SendData(SPI2, 0x00); while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_RXNE) == RESET); reg_rdata[n1] = SPI_I2S_ReceiveData(SPI2); } GPIO_SetBits(GPIOB, SPI_CS_PIN); #stm32f4
dear sir,
I use the STM32F4 uP to control peripheral IC by SPI protocol. And I composed the source code according to the the reference manual (Doc ID 018909 Rev 5). However, the data is invalid after SPI_I2S_FLAG_RXNE asserted. The data is valid after more than 1us. By a scope, the peripheral IC sends the data correctly. It seem not accordant with the the figure as the following.
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STM32F4 Series
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2014-03-17 10:51 AM
Posted on March 17, 2014 at 18:51
Try with this
SPI Read
GPIO_ResetBits(GPIOB, SPI_CS_PIN);
GPIO_ResetBits(GPIOB, SPI_CS_PIN); // repeat CS select if you want add delay before start read
GPIO_ResetBits(GPIOB, SPI_CS_PIN);
// here CS ok
n1 = 0 ;
while (n1 < reg_num)
{
if (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_TXE) != RESET)
{
SPI_I2S_SendData(SPI2, 0x00);
}
if (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_RXNE) != RESET)
{
reg_rdata[n1++] = SPI_I2S_ReceiveData(SPI2);
}
}
GPIO_SetBits(GPIOB, SPI_CS_PIN);
