SPI slave - different behavior without debugger

Hi,

I am using STM32L051R8T6 and i have implemented an SPI slave using the HAL libraries.

I am using DMA. the master is an FPGA. SPI clock is ~2Mhz.

The FPGA initiate 2 read commands for each read from the MCU - 1 for it to prepare the data and 1 to read it. all of the commands are fixed length of 7 Bytes.

When using a debugger it is working but when i reset the board and load without a debugger i get different results - the bytes seems shifted. attached are the 2 scenarios from the signal tap of the FPGA.

We tried increasing the delay between the 2 messages and it didn't

this is how my SPI is configured:

 /* SPI2 parameter configuration*/

 hspi2.Instance = SPI2;

 hspi2.Init.Mode = SPI_MODE_SLAVE;

 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_HARD_INPUT;

 hspi2.Init.FirstBit = SPI_FIRSTBIT_LSB;

 hspi2.Init.TIMode = SPI_TIMODE_DISABLE;

 hspi2.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;

 hspi2.Init.CRCPolynomial = 7;

 if (HAL_SPI_Init(&hspi2) != HAL_OK)

 {

  Error_Handler();

 }

  /* SPI2 DMA Init */

  /* SPI2_RX Init */

  hdma_spi2_rx.Instance = DMA1_Channel4;

  hdma_spi2_rx.Init.Request = DMA_REQUEST_2;

  hdma_spi2_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;

  hdma_spi2_rx.Init.PeriphInc = DMA_PINC_DISABLE;

  hdma_spi2_rx.Init.MemInc = DMA_MINC_ENABLE;

  hdma_spi2_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;

  hdma_spi2_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;

  hdma_spi2_rx.Init.Mode = DMA_CIRCULAR;

  hdma_spi2_rx.Init.Priority = DMA_PRIORITY_VERY_HIGH;

  if (HAL_DMA_Init(&hdma_spi2_rx) != HAL_OK)

  {

   Error_Handler();

  }

  __HAL_LINKDMA(hspi,hdmarx,hdma_spi2_rx);

  /* SPI2_TX Init */

  hdma_spi2_tx.Instance = DMA1_Channel5;

  hdma_spi2_tx.Init.Request = DMA_REQUEST_2;

  hdma_spi2_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;

  hdma_spi2_tx.Init.PeriphInc = DMA_PINC_DISABLE;

  hdma_spi2_tx.Init.MemInc = DMA_MINC_ENABLE;

  hdma_spi2_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;

  hdma_spi2_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;

  hdma_spi2_tx.Init.Mode = DMA_CIRCULAR;

  hdma_spi2_tx.Init.Priority = DMA_PRIORITY_VERY_HIGH;

  if (HAL_DMA_Init(&hdma_spi2_tx) != HAL_OK)

  {

   Error_Handler();

  }

  __HAL_LINKDMA(hspi,hdmatx,hdma_spi2_tx);

  /* SPI2 interrupt Init */

  HAL_NVIC_SetPriority(SPI2_IRQn, 0, 0);

  HAL_NVIC_EnableIRQ(SPI2_IRQn);