基于STM32F103--I2S2、I2S3的“伪全双工”音频接口初始化

        stm32f103的芯片是半双工的I2S，但有两路I2S，所以可以同时将一路配置为主接收（录音），另外一路配置为主发送（播放）。

        需要注意的是，启用I2S3，需要先失能jtag。以下是代码部分：

.h

#include "sys.h" 
#include <stdio.h>

extern u8 I2S_RX;
extern u8 I2S_TX;

extern uint32_t I2S2_Rx_Cnt ;
extern uint32_t I2S3_Tx_Cnt ;
extern uint8_t I2S2_Buffer_Rx[Rx_Len];
extern uint8_t I2S3_Buffer_Tx[Tx_Len];

void STM32F10X_I2S_Init(void);

.c

#include "bsp_i2s.h"

#define Rx_Len  1024*24
#define Tx_Len  1024*24

uint32_t I2S2_Rx_Cnt = 0;
uint32_t I2S3_Tx_Cnt = 0;

uint8_t I2S2_Buffer_Rx[Rx_Len];
uint8_t I2S3_Buffer_Tx[Tx_Len];

/*
**************************************************************************
*	函 数 名: I2S_NVIC_Config
*	功能说明: 配置I2S NVIC通道(中断模式)。
*	形    参:  无
*	返 回 值: 无
**************************************************************************
*/
static void I2S_NVIC_Config(void)
{
  NVIC_InitTypeDef NVIC_InitStructure;

#ifdef  VECT_TAB_RAM
  /* Set the Vector Table base location at 0x20000000 */
  NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
#else  /* VECT_TAB_FLASH  */
  /* Set the Vector Table base location at 0x08000000 */
  NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
#endif

  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

  /* SPI2 IRQ Channel configuration */
  NVIC_InitStructure.NVIC_IRQChannel = SPI2_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

  /* SPI3 IRQ channel configuration */
  NVIC_InitStructure.NVIC_IRQChannel = SPI3_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
  NVIC_Init(&NVIC_InitStructure);
}
 /*
*************************************************************************
*	函 数 名: STM32F10X_I2S_Init
*	功能说明: 配置I2S
*	形    参: 无
*	返 回 值: 无
*************************************************************************
*/
void STM32F10X_I2S_Init(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	I2S_InitTypeDef I2S_InitStructure;

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);

	/* SPI2 and SPI3 clocks enable */
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2 | RCC_APB1Periph_SPI3, ENABLE);

	/* Disable the JTAG interface and enable the SWJ interface */
	GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);

	/* Configure SPI2 pins: CK, WS and SD --------------------------------*/
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_15;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
	GPIO_Init(GPIOB, &GPIO_InitStructure);
		
	/* Configure I2S2 pins: MCK ------------------------------------------*/
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 ;
	GPIO_Init(GPIOC, &GPIO_InitStructure);

	/* Configure SPI3 pins: CK and SD ------------------------------------*/
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3 | GPIO_Pin_5;
	GPIO_Init(GPIOB, &GPIO_InitStructure);

	/* Configure SPI3 pins: WS -------------------------------------------*/
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
	GPIO_Init(GPIOA, &GPIO_InitStructure);

	/* Configure I2S3 pins: MCK ------------------------------------------*/
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7 ;
	GPIO_Init(GPIOC, &GPIO_InitStructure);
		
	/* I2S peripheral configuration */
	I2S_InitStructure.I2S_Standard = I2S_Standard_Phillips;
	I2S_InitStructure.I2S_DataFormat = I2S_DataFormat_16b;//extended
	I2S_InitStructure.I2S_MCLKOutput = I2S_MCLKOutput_Enable;
	I2S_InitStructure.I2S_AudioFreq = I2S_AudioFreq_16k;
	I2S_InitStructure.I2S_CPOL = I2S_CPOL_Low;

	/* I2S2 Master Transmitter to I2S3 Slave Receiver communication ------------*/
	/* I2S2 configuration */
	I2S_InitStructure.I2S_Mode = I2S_Mode_MasterRx;
	I2S_Init(SPI2, &I2S_InitStructure);

	/* I2S3 configuration */
	I2S_InitStructure.I2S_Mode = I2S_Mode_MasterTx;
	I2S_Init(SPI3, &I2S_InitStructure);

	/* Enable the I2S2 RxNE interrupt */
	SPI_I2S_ITConfig(SPI2, SPI_I2S_IT_RXNE, ENABLE);

	/* Enable the I2S3 TxE interrupt */
	SPI_I2S_ITConfig(SPI3, SPI_I2S_IT_TXE, ENABLE);

//	/* Enable the I2S2 */
	I2S_Cmd(SPI2, ENABLE);

//	/* Enable the I2S3 */
	I2S_Cmd(SPI3, ENABLE);

	I2S_NVIC_Config();
}


void SPI2_IRQHandler()
{
  if (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_IT_RXNE) == SET)
	{	
		2S2_Buffer_Rx[I2S2_Rx_Cnt++] = SPI_I2S_ReceiveData(SPI2);
    }
			
}

void SPI3_IRQHandler()
{
	if (SPI_I2S_GetITStatus(SPI3, SPI_I2S_IT_TXE) == SET)
	{
		/* Send a data from I2S2 */
		SPI_I2S_SendData(SPI3, I2S3_Buffer_Tx[I2S3_Tx_Cnt++]);
	}

	/* Check the end of buffer transfer */
	if (I2S3_Tx_Cnt == Tx_Len)
	{
		/* Disable the I2S2 TXE interrupt to end the communication */
		SPI_I2S_ITConfig(SPI3, SPI_I2S_IT_TXE, DISABLE);
		I2S3_Tx_Cnt = 0;
	}
}