Эффективность чтения датчиков SPI через DMA в режиме реального времени

void SysTick_Handler(void)
{
GPIOE_BSRR|=0x80000;
DMA2_S3CR|=0x1;
}
 
void USORT_TX(uint32_t y)
{
USORT2_DR=y-127;// центрируем график с осей по центру экрана
while (!(USORT2_SR&0x80)==0x80){}
}
 
void SystemInit(void)
{
}
 
uint8_t x[] ={0xA9,0};//Адрес регистров осей акселерометра которые будут считываться.
uint8_t y[2];
uint8_t z;
uint32_t i;
 
void USORT_ini(void)
{
RCC_GPIO|=0x1;
GPIOA_MODER|=0xA0; 
GPIOA_AFRL|=0x7700; 
RCC_UART2|=0x20000; 
USORT2_BRR=0x683;
USORT2_CR3|=0x80;
USORT2_CR1|=0x8;
NVIC_ISER1|=0x40;
USORT2_CR1|=0x2000;
}
 
void SPI_ini(void)
{ 
RCC_GPIO|=0x19;
 
GPIOA_MODER|=0xA800;
GPIOA_AFRL|=0x55500000; 
 
GPIOE_MODER|=0x40;
GPIOE_PUPDR|=0x40;
GPIOE_BSRR|=0x8;
 
RCC_SPI1|=0x1000;
 
SPI1_CR1 |= 0x0002 |0x0001; 
SPI1_CR1 |=0x0300|0x0028;
SPI1_CR1 |=0x04;
SPI1_CRCPR=7;
SPI1_CR2|=0x3;
SPI1_CR1|=0x0040;
 
GPIOE_BSRR=0x80000;
SPI1_DR=0x20;
while (!(SPI1_SR&0x1)==0x1){};
z=SPI1_DR;
SPI1_DR=0x97; 
while (!(SPI1_SR&0x1)==0x01){}
z=SPI1_DR;  
GPIOE_BSRR=0x8; 
}
 
void DMA_ini(void)
{ 
DMA1_RCC|=0x200000;
DMA2_RCC|=0x400000;
//.....................TX
DMA2_S3CR= 0x06000000;//DMA_Channel_3;
DMA2_S3PAR=0x4001300C;//SPI->DR
DMA2_S3M0AR= (uint32_t)x;
DMA2_S3CR|= 0x40;//DMA_DIR_MemoryToPeripheral;
DMA2_S3NDTR=2;
DMA2_S3CR|=0x0400;
DMA2_S3CR|=0x10000;
//DMA2_S3CR|=0x8;
//DMA2_S3CR|=0x100;//DMA_CIRCULAR
DMA2_S3CR|=0x10;
 
NVIC_ISER1=0x8000000;
DMA2_S3CR|=0x10;
//....................RX
DMA2_S0CR= 0x06000000;//DMA_Channel_3;
DMA2_S0PAR=0x4001300C;//SPI->DR
DMA2_S0M0AR=(uint32_t)y;
DMA2_S0CR|= 0;//peripheralToMemory
DMA2_S0NDTR=2;
DMA2_S0CR|=0x400;
DMA2_S0CR|=0x10000;
//DMA2_S0CR|=0x100;
DMA2_S0CR|=0x10;
 
NVIC_ISER1=0x1000000;
DMA2_S0CR|=0x10;
} void DMA2_Stream0_IRQHandler(void)//...........SPI->RX
{ 
GPIOE_BSRR=0x8;
DMA2_LIFCR=0x20;
USORT_TX(y[1]);
}
 
void DMA2_Stream3_IRQHandler(void)//...........SPI->TX
{ 
GPIOE_BSRR=0x80000;
if((DMA2_LISR&0x8000000)==0x8000000)
{DMA2_LIFCR=0x8000000;
DMA2_S0CR|=0x1;}
}
void DMA1_Stream6_IRQHandler(void)
{ 
 
if((DMA_HISR&0x200000)==0x200000)
DMA_HIFCR=0x200000;
}
 
int main(void)
{
USORT_ini();
SPI_ini();
DMA_ini();
GPIOD_MODER|=0x55000000;
GPIOD_OTYPER|=0x55000000;
SysTic_RVR=0xFFF;
SysTic_CVR=0x0;
SysTic_CTRL_Status=0x10007;
while(1)
{
GPIOD_ODR=0xF000;
for(i=0;i<1000000;i++){};
GPIOD_ODR=0x0;
for(i=0;i<1000000;i++){};
}
}