SPI STM

//note: I know that names of functions are messed up, I did it on purpose.
//note: no SPL... no exceptions

void SPI3Init()
{

    RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN | RCC_AHB1ENR_GPIOBEN;
    RCC->APB2ENR |= RCC_APB2ENR_SPI1EN;
//  GPIOB->MODER |= (2<<(3*2)) | (2<<(4*2)) | (2<<(5*2));
    GPIOA->MODER |= (2<<(MOSI1*2)) | (2<<(MISO1*2)) | (2<<(SCK1*2));
//  GPIOB->AFR[0]|= (spin<<(3*4)) |(spin<<(4*4)) |(spin<<(5*4));
    GPIOA->AFR[0]|= (5<<(MOSI1*4)) | (5<<(MISO1*4)) | (5<<(SCK1*4));
    SPI1->CR1 |= SPI_BRPsc_8 | SPI_CR1_SSM | SPI_CR1_SSI;// | SPI_CR1_LSBFIRST;
    SPI1->CR1 |= SPI_CR1_SPE | SPI_CR1_MSTR;

}

//SPI1_MISO -> PA6
//SPI1_MOSI -> PA7
//SPI1_SCK  -> PA5

uint8_t SPI3_send(unsigned char n)
{
    SPI1->DR = n;
    while(!(SPI1->SR & (SPI_SR_TXE)));
    while(!(SPI1->SR & (SPI_SR_RXNE)));
    return (SPI1->DR);
}