stm8s103 SPI按规格书一步步写就是通信不了

只看该作者 · 2017-10-30 17:02

主机IO口初始化
  //CSK--->PC5
  PC_DDR_bit.DDR5 = 1;
  PC_CR1_bit.C15 = 1;
  PC_CR2_bit.C25 = 1;
  //MOSI--->PC6
  PC_DDR_bit.DDR6 = 1;
  PC_CR1_bit.C16 = 1;
  PC_CR2_bit.C26 = 1;
  //MISO--->PC7
  PC_DDR_bit.DDR7 = 0;
  PC_CR1_bit.C17 = 0;
  PC_CR2_bit.C27 = 0;
  //NSS--->PA3
  PA_DDR_bit.DDR3 = 1;
  PA_CR1_bit.C13 = 1;
  PA_CR2_bit.C23 = 1;

SPI设置
void  SPI_Init()
{
SPI_CR1_bit.BR = 1;    //设置SPI速率  /4
SPI_CR1_bit.CPOL = 0; //
SPI_CR1_bit.CPHA = 0;
SPI_CR1_bit.MSTR = 1;    //主设备模式
SPI_CR2_bit.SSI = 1;       //主设备 SSI引脚不用
SPI_CR2_bit.SSM = 1;
SPI_CR1_bit.LSBFIRST = 0; //先发送MSB位
SPI_CR1_bit.SPE = 1;       //使能SPI设备
}

写入单字节
unsigned char spi_rw_byte(unsigned char byte)
{
  unsigned char retry = 0;

  while(SPI_SR_bit.TXE == 0)
  {
retry++;
if(retry > 200)
   return 0;
  }
  SPI_DR = byte;

  retry=0;
  while(SPI_SR_bit.RXNE == 0)  //等待接收完一个byte
  {
retry++;
if(retry > 200)return 0;
  }

  return SPI_DR;       //返回收到的数据
}

主函数
初始化后一秒钟发个字节
spi_io_initial();
  SPI_Init();
while(1)
  {
SPI_NSS=0;
spi_rw_byte(a);
SPI_NSS=1;
delay(1000);
LED=~LED;
a++;
  }

//////////////////////////
从机
IO口初始化
  //CSK--->PC5
  PC_DDR_bit.DDR5 = 0;
  PC_CR1_bit.C15 = 0;
  PC_CR2_bit.C25 = 0;
  //MOSI--->PC6
  PC_DDR_bit.DDR6 = 0;
  PC_CR1_bit.C16 = 0;
  PC_CR2_bit.C26 = 0;
  //MISO--->PC7
  PC_DDR_bit.DDR7 = 1;
  PC_CR1_bit.C17 = 1;
  PC_CR2_bit.C27 = 1;
  //SPI_NSS--->PA3
  PA_DDR_bit.DDR3 = 0;
  PA_CR1_bit.C13 = 1;
  PA_CR2_bit.C23 = 0;

SPI设置
void  SPI_Init()
{
// SPI_CR1_bit.BR = 1;    //设置SPI速率  /4
SPI_CR1_bit.CPOL = 0; //空闲时SCK为高
SPI_CR1_bit.CPHA = 0; //数据从第一个时钟沿开始
SPI_CR1_bit.LSBFIRST = 0; //先发送MSB位
SPI_CR2_bit.SSM = 0;
SPI_CR2_bit.SSI = 0;
SPI_CR1_bit.MSTR = 0;    //从设备模式
SPI_CR2_bit.SSM = 1;       //使能SPI设备
}

写入单字节
unsigned char spi_rw_byte(unsigned char byte)
{
  unsigned char retry = 0;

  while(SPI_SR_bit.TXE == 0)
  {
retry++;
if(retry > 200)
   return 0;
  }
  SPI_DR = byte;

  retry=0;
  while(SPI_SR_bit.RXNE == 0)  //等待接收完一个byte
  {
retry++;
if(retry > 200)return 0;
  }

  return SPI_DR;       //返回收到的数据
}

主函数
等待中断接收数据改变指示灯
  spi_io_initial();
  SPI_Init();
  SPI_ICR = 0x40;
  asm("rim");

while(1);

/**    SPI中断服务函数    */
#pragma vector = 12
__interrupt void SPI_IRQHandler(void)
{
  if(SPI_SR_bit.RXNE==1)
  LED=~LED;

SPI_SR_bit.RXNE=0;
｝

//////////////////////////////////////
主机和从机基本这么写了的，用swim调试，就没看见SPI_DR里面有过数据，从机也没看见进过中断，请问高手们，我这个是主机还是从机，哪里有问题，就是不可以用呢？