Posted on October 08, 2013 at 18:21Ok, thanks for your replay. This is the code :
#include ''stm32f30x.h''
/**
* @brief Configures the different GPIO ports.
* @param None
* @retval None
*/
/* variables ---------------------------------------------------------*/
GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef SPI_InitStructure;
/* Set up GPIO for SPI */
void SPI_GPIO_init(){
//Disable SPI
SPI_I2S_DeInit(SPI1);
// Enable clock for SPI 1
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
// Enable Clock for SPI GPIOA
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
// Set up SCLK, MISO and MOSI pins
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7; // Select pins ( SCLK | MISO | MOSI)
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; // Set as AF mode
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
// Configure GPIO Alternate function as SPI1
GPIO_PinAFConfig(GPIOA, GPIO_Pin_5, GPIO_AF_5); // SPI1 SCLK
GPIO_PinAFConfig(GPIOA, GPIO_Pin_6, GPIO_AF_5); // SPI1 MISO
GPIO_PinAFConfig(GPIOA, GPIO_Pin_7, GPIO_AF_5); // SPI1 MOSI
// Set up CS pin
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15; // PA15 taken as SPI1_NSS
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
// OType, Speed and PuPd are the same
GPIO_Init(GPIOA, &GPIO_InitStructure);
}
/* Set up SPI and related parameters */
void SPI_init(){
// Configure SPI
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_32;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial = 7;
SPI_Init(SPI1, &SPI_InitStructure);
// Enable SPI1
SPI_Cmd(SPI1, ENABLE);
// ensure RXNE is initially clear
SPI_ReceiveData8(SPI1);
}
/**
* @brief write data width bytes from SPI interface.
* @param passed address & data
* @retval None
*/
void write(uint8_t address, uint32_t data )
{
int x=0;
uint8_t * txBuffer = (uint8_t*)&data;
// gpio init
SPI_GPIO_init();
// Init SPI1
SPI_init();
/* Transfer procedure */
/* Wait for SPI1 Tx buffer empty */
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
GPIO_WriteBit( GPIOA,GPIO_Pin_15,Bit_RESET ); // drive the CS line low
/* Send SPI address */
SPI_SendData8(SPI1, address);
for (x=3; x >= 0 ; x-- ) {
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
/* Send SPI data high */
SPI_SendData8(SPI1, txBuffer[x]);
}
//wait for last bit to be sent
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
GPIO_WriteBit(GPIOA, GPIO_Pin_15,Bit_SET ); // drive the CS line high
}
But
SPI_SendData8() doesn't write data to DR register, because it has :
void SPI_SendData8(SPI_TypeDef* SPIx, uint8_t Data)
{
uint32_t spixbase = 0x00;
/* Check the parameters */
assert_param(IS_SPI_ALL_PERIPH(SPIx));
spixbase = (uint32_t)SPIx;
spixbase += 0x0C;
*(__IO uint8_t *) spixbase = Data;
}
