6 years ago.

SPI master and slave at the same time (NUCLEO-L432KC)

I'm testing my small project using SPI. In that project, the mbed board (Nucleo-L432KC) has to receive data from a SPI master, and send processed data to another device as a SPI master. Then, the board should work as a SPI slave and a SPI master at the same time.

Nucleo-L432KC has 2 SPI (SPI1 and SPI3) and so I tried to configure both of them, but SCLK output as a master didn't work. Is it possible to use 2 SPI as a master and a slave?

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Configuration

SPI1 as a slave using MOSI = A6, MISO = A5, SCLK = A4, SSEL = D3 format:(8,3), frequency:6750000

SPI3 as a master using MOSI = D11, MISO = D12, SCLK = D13, SSEL = D9 format:(8,3), frequency:6750000

If they are not configured at the same time, it seems to work well.

a part of my code:

    SPI_3_SSEL = 1;
    spi_3.format(SPI_3_BITS, SPI_3_MODE);
    spi_3.frequency(SPI_3_FREQ);
    SPI3->CR1 &= ~0x80;                                 //MSBFirst
   
    spi_1.format(SPI_1_BITS, SPI_1_MODE);
    spi_1.frequency(SPI_1_FREQ);
    SPI1->CR1 |= 0x80;                                  //LSBFirst
    SPI1->CR2 |= 0x40;                                  //Interrupt
    NVIC_SetVector(SPI1_IRQn, (uint32_t) &intrrptSPI1); //Callback function
    NVIC_SetPriority(SPI1_IRQn, 1);                     //Priority
    NVIC_EnableIRQ(SPI1_IRQn);                          //Enable interrupt