SPI Protocol Polarity Issue " hspi2.Init.CLKPolarity "
I set up a basic Master-Slave SPI communication interface from the STM32H750VBT to the STM32F7ZET MCUs in only one direction. And in this workspace I set my hspi2.Init.CLKPolarity configuration as SPI_POLARITY_LOW on both sides. And, as far as I know it is enough if we make the polarity same on both side either HIGH or LOW. However the communication occasionally get lost. After this happens I tried to change polarity as HIGH. And I suddenly saw that the communication was ok again. I was just like "Wow!" what is that now? Do i miss anything guys? I mean how it can be possible since everything is same such as electronics board and the software.
void MX_SPI2_Init(void)
{
hspi2.Instance = SPI2;
hspi2.Init.Mode = SPI_MODE_MASTER;
hspi2.Init.Direction = SPI_DIRECTION_2LINES;
hspi2.Init.DataSize = SPI_DATASIZE_8BIT;
hspi2.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi2.Init.CLKPhase = SPI_PHASE_1EDGE;
hspi2.Init.NSS = SPI_NSS_SOFT;
hspi2.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_32;
hspi2.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi2.Init.TIMode = SPI_TIMODE_DISABLE;
hspi2.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi2.Init.CRCPolynomial = 7;
hspi2.Init.NSSPMode = SPI_NSS_PULSE_ENABLE;
hspi2.Init.NSSPolarity = SPI_NSS_POLARITY_LOW;
hspi2.Init.FifoThreshold = SPI_FIFO_THRESHOLD_01DATA;
hspi2.Init.TxCRCInitializationPattern = SPI_CRC_INITIALIZATION_ALL_ZERO_PATTERN;
hspi2.Init.RxCRCInitializationPattern = SPI_CRC_INITIALIZATION_ALL_ZERO_PATTERN;
hspi2.Init.MasterSSIdleness = SPI_MASTER_SS_IDLENESS_00CYCLE;
hspi2.Init.MasterInterDataIdleness = SPI_MASTER_INTERDATA_IDLENESS_00CYCLE;
hspi2.Init.MasterReceiverAutoSusp = SPI_MASTER_RX_AUTOSUSP_DISABLE;
hspi2.Init.MasterKeepIOState = SPI_MASTER_KEEP_IO_STATE_DISABLE;
hspi2.Init.IOSwap = SPI_IO_SWAP_DISABLE;
if (HAL_SPI_Init(&hspi2) != HAL_OK)
{
// Error_Handler();
}
}I will be very appreciated if you could help me about this problem asap.
Thanks in Advance.
I used the following initial parameters for the SPI bus
