Spi clock is not generated

[mandar1712]

Hello, 

I am trying to generate spi clock(100kz) in stm32g473,but desired output not getting in DSO .I tried to change  stm32cubemx configuration then i changed the user code then also not getting desired output.

Please help me what changes I needed to generate clock.

 Thank you in advance.

[gbm]

It's impossible to suggest the changes without seeing the code. SPI clock is output only when you send the data. SPI will not output the clock signal unless you transmit something.

[waclawek.jan]

Read out and check/post content of SPI and relevant GPIO registers.

What hardware? You can check proper connection of SPI_SCK by setting given pin to GPIO Output and toggling "manually" (i.e. doing a basic "blinky").

JW

[mandar1712]

here is configuration i did in the stm32cubemx

void MX_SPI1_Init(void)
{

hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_MASTER;
hspi1.Init.Direction = SPI_DIRECTION_2LINES;

hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
hspi1.Init.NSS = SPI_NSS_SOFT;
hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_128;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 7;
hspi1.Init.CRCLength = SPI_CRC_LENGTH_DATASIZE;
hspi1.Init.NSSPMode = SPI_NSS_PULSE_DISABLE;
if (HAL_SPI_Init(&hspi1) != HAL_OK)
{
Error_Handler();
}

}

void HAL_SPI_MspInit(SPI_HandleTypeDef* spiHandle)
{

GPIO_InitTypeDef GPIO_InitStruct = {0};
if(spiHandle->Instance==SPI1)
{
/* USER CODE BEGIN SPI1_MspInit 0 */

/* USER CODE END SPI1_MspInit 0 */
/* SPI1 clock enable */
__HAL_RCC_SPI1_CLK_ENABLE();

__HAL_RCC_GPIOA_CLK_ENABLE();
/**SPI1 GPIO Configuration
PA5 ------> SPI1_SCK
PA6 ------> SPI1_MISO
PA7 ------> SPI1_MOSI
*/
GPIO_InitStruct.Pin = GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = GPIO_AF5_SPI1;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

/* USER CODE BEGIN SPI1_MspInit 1 */

/* USER CODE END SPI1_MspInit 1 */
}
}

void MX_GPIO_Init(void)
{

GPIO_InitTypeDef GPIO_InitStruct = {0};

/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOF_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();

/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_4, GPIO_PIN_RESET);

/*Configure GPIO pin : PA4 */
GPIO_InitStruct.Pin = GPIO_PIN_4;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

}

user code

while (1)
{
/* USER CODE END WHILE */

/* USER CODE BEGIN 3 */
HAL_GPIO_WritePin(GPIOA,GPIO_PIN_4,GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOA,GPIO_PIN_4,GPIO_PIN_RESET);
HAL_Delay(1000);
HAL_SPI_Transmit(&hspi1,&data,1,HAL_MAX_DELAY);
HAL_GPIO_WritePin(GPIOA,GPIO_PIN_4,GPIO_PIN_SET);
HAL_Delay(1000);
}
/* USER CODE END 3 */
}

[mandar1712]

yes i tried  this clock is toggling.

[AScha.3]

Hi,

Just to clarify: you send 1 byte every 2 seconds ;

set data to something ? like : 0xAA , then you see some pulses on data line ?

+ 8 pulses on clk line ? ( every 2 seconds )

[mandar1712]

I declared data variable to 0xAA in above code 

But no any pulses on data line .

[waclawek.jan]

Read out and check/post content of SPI and relevant GPIO registers.

JW