LTC2983 with STM32F407 - Status Command Register(0x00) is zero after POR

Hi

I'm developing SW works on STM32F407. I've tried read status command register(0x00), after POR but the value is always zero. Even I've written 0x80 and read it, but still 0x00.

Sequence

1. Power On

2. Wait for POR completion ( At least 2 secs from power on)

3. Read 0x00 register using SPI

  • I expects 0x80 or 0x40, but always 0x00.

Here is my SPI configuration

/* SPI1 init function */
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_64;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 10;


 if (HAL_SPI_Init(&hspi1) != HAL_OK)
 {
   Error_Handler();
  }

}

SPI clock is 1.3MHz (APB2 clock is 84MHz)

Here is a capture

Thanks in advance,

Ken