最近参考原子哥的SAI例子和标准库的例子用HAL库配置I2S,“目前的采样率设置为16KHz，但是主时钟和帧时钟都没有电平输出”,希....

13172467542 · 发表于 2017-5-27 15:11:10

/* I2S 引脚复用初始化 */
void HAL_I2S_MspInit(I2S_HandleTypeDef *hi2s)
{

__HAL_RCC_GPIOC_CLK_ENABLE() ;  /* GPIO Ports Clock Enable */
__HAL_RCC_GPIOB_CLK_ENABLE();
  __HAL_RCC_SPI2_CLK_ENABLE();

  GPIO_InitTypeDef  GPIO_Initure1;
  GPIO_InitTypeDef  GPIO_Initure2;
  GPIO_InitTypeDef  GPIO_Initure3;

  GPIO_Initure1.Pin = GPIO_PIN_10|GPIO_PIN_12|GPIO_PIN_15;
  GPIO_Initure1.Mode = GPIO_MODE_AF_PP;
  GPIO_Initure1.Pull=GPIO_PULLUP;
  GPIO_Initure1.Speed = GPIO_SPEED_FREQ_HIGH;
  GPIO_Initure1.Alternate = GPIO_AF5_SPI2;

  GPIO_Initure2.Pin= GPIO_PIN_2;
  GPIO_Initure2.Mode=GPIO_MODE_AF_PP;
  GPIO_Initure2.Pull=GPIO_PULLUP;
  GPIO_Initure2.Speed = GPIO_SPEED_FREQ_HIGH;
  GPIO_Initure2.Alternate= GPIO_AF6_I2S2ext;

  GPIO_Initure3.Pin= GPIO_PIN_6;
  GPIO_Initure3.Mode=GPIO_MODE_AF_PP;
  GPIO_Initure3.Pull=GPIO_PULLUP;
  GPIO_Initure3.Speed=GPIO_SPEED_FREQ_HIGH;
  GPIO_Initure3.Alternate= GPIO_AF5_SPI2;

  HAL_GPIO_Init(GPIOB, &GPIO_Initure1);    //PB10/12/15  复用功能输出
  HAL_GPIO_Init(GPIOC, &GPIO_Initure2);
  HAL_GPIO_Init(GPIOC, &GPIO_Initure3);    //PC2/6    复用功能输出

}

//采样率计算公式:Fs=I2SxCLK/[256*(2*I2SDIV+ODD)]
//I2SxCLK=(HSE/pllm)*PLLI2SN/PLLI2SR
//一般HSE=8Mhz
//pllm:在Sys_Clock_Set设置的时候确定，一般是8
//PLLI2SN:一般是192~432
//PLLI2SR:2~7
//I2SDIV:2~255
//ODD:0/1
//I2S分频系数表@pllm=25,HSE=25Mhz,即vco输入频率为1Mhz
//表格式:采样率/10,PLLI2SN,PLLI2SR,I2SDIV,ODD
const u16 I2S_PSC_TBL[][5]=
{
{800 ,256,5,12,1}, //8Khz采样率
{1102,429,4,19,0}, //11.025Khz采样率
{1600,213,2,13,0}, //16Khz采样率  open MCLK
{2205,429,4, 9,1}, //22.05Khz采样率
{3200,213,2, 6,1}, //32Khz采样率
{4410,271,2, 6,0}, //44.1Khz采样率
{4800,258,3, 3,1}, //48Khz采样率
{8820,316,2, 3,1}, //88.2Khz采样率
{9600,344,2, 3,1},    //96Khz采样率
{17640,361,2,2,0},    //176.4Khz采样率
{19200,393,2,2,0},    //192Khz采样率
};

//设置IIS的采样率(@MCKEN)
//samplerate:采样率,单位:Hz
//返回值:0,设置成功;1,无法设置.
u8 I2S2_SampleRate_Set(u32 samplerate)
{
u8 i=0;
u32 tempreg=0;
samplerate/=10;//缩小10倍
for(i=0;i<(sizeof(I2S_PSC_TBL)/10);i++)//看看改采样率是否可以支持
{
if(samplerate==I2S_PSC_TBL[i][0])break;
}
__HAL_RCC_PLLI2S_DISABLE();; //先关闭PLLI2S
if(i==(sizeof(I2S_PSC_TBL)/10))return 1;//搜遍了也找不到
tempreg|=(u32)I2S_PSC_TBL[i][1]<<6; //设置PLLI2SN
tempreg|=(u32)I2S_PSC_TBL[i][2]<<28; //设置PLLI2SR
RCC->PLLI2SCFGR=tempreg; //设置I2SxCLK的频率(x=2)
RCC->CR|=1<<26; //开启I2S时钟
while((RCC->CR&1<<27)==0); //等待I2S时钟开启成功.
tempreg=I2S_PSC_TBL[i][3]<<0; //设置I2SDIV
tempreg|=I2S_PSC_TBL[i][4]<<8; //设置ODD位
tempreg|=1<<9; //使能MCKOE位,输出MCK
SPI2->I2SPR=tempreg; //设置I2SPR寄存器
return 0;
}
/*I2S 数据格式初始化 */
//std:I2S标准,00,飞利浦标准;01,MSB对齐标准(右对齐);10,LSB对齐标准(左对齐);11,PCM标准
//mode:I2S工作模式,00,从机发送;01,从机接收;10,主机发送;11,主机接收
//cpol:0,时钟低电平有效;1,时钟高电平有效
//datalen:数据长度,0,16位标准;1,16位扩展(frame=32bit);2,24位;3,32位
  static void My_I2S2_Init(void)
{
  I2S_HandleTypeDef HI2S;

  __HAL_I2S_DISABLE(&HI2S);
  HI2S.Instance = SPI2;
  HI2S.Init.MCLKOutput =I2S_MCLKOUTPUT_ENABLE;
  HI2S.Init.Mode = I2S_MODE_MASTER_TX;    //I2S主机发送工作模式
  HI2S.Init.Standard = I2S_STANDARD_PHILIPS; //I2S飞利浦标准
  HI2S.Init.DataFormat = I2S_DATAFORMAT_16B; //数据长度16位
  HI2S.Init.MCLKOutput = I2S_MCLKOUTPUT_DISABLE;
  HI2S.Init.AudioFreq = I2S_AUDIOFREQ_16K;
  HI2S.Init.CPOL = I2S_CPOL_HIGH;
  HI2S.Init.ClockSource = I2S_CLOCK_PLL;
  HI2S.Init.FullDuplexMode = I2S_FULLDUPLEXMODE_ENABLE;
  HI2S.State=HAL_I2S_STATE_RESET;
  if(HAL_I2S_GetState(&HI2S) == HAL_I2S_STATE_RESET)
  {
   HAL_I2S_MspInit(&HI2S);
  }
   HAL_I2S_Init(&HI2S);
__HAL_I2S_ENABLE(&HI2S);    //SPI2 I2S EN 使能
}
int  main(void)
{
Stm32_Clock_Init(384,25,2,8); //设置时钟,192Mhz
delay_init(192);             //初始化延时函数
My_I2S2_Init();
I2S2_SampleRate_Set(16000);
while(1)
{

};
}