K210 as SPI Slave

  • I read, that SPI2 supports slave mode. How many lines can I use then? I also did not get which SPI (number) the dedicated SPI for flash is. What do I need to do to set up the K210 as SPI slave? Also the fpioa_function_t has only three slave pins acc. to the programming manual.

    FUNC_SPI_SLAVE_D0 = 84 / *! <SPI Slave Data 0 * /
    FUNC_SPI_SLAVE_SS = 85 / *! <SPI Slave Select * /
    FUNC_SPI_SLAVE_SCLK = 86 / *! <SPI Slave Serial Clock * /

    I would not know how to start from here. Any suggestions for a starting point on this?