【STM32 HAL库】全双工I2S+双缓冲DMA的使用

1、配置I2S

我们的有效数据是32位的，使用飞利浦格式。

2、配置DMA

**这里需要注意：**i2s的DR寄存器是16位的，如果需要发送32位的数据，是需要写两次DR寄存器的，所以DMA的外设数据宽度设置16位，而不是32位。

3、完善I2S文件

i2s.c和i2s.h文件都是MX自动生成的，并且生成MX_I2S3_Init函数进行了初始化，MX_I2S3_Init函数里面其实依次调用了HAL_I2S_Init库函数（和MCU不相关的初始化）和HAL_I2S_MspInit库函数（是个weak函数，和MCU相关的初始化）。所以，我们自己要写的代码也加到这个文件中。

/* USER CODE BEGIN Header */
/********************************************************************************* @file    i2s.c* @brief   This file provides code for the configuration*          of the I2S instances.******************************************************************************* @attention** Copyright (c) 2024 STMicroelectronics.* All rights reserved.** This software is licensed under terms that can be found in the LICENSE file* in the root directory of this software component.* If no LICENSE file comes with this software, it is provided AS-IS.********************************************************************************/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "i2s.h"/* USER CODE BEGIN 0 */
#include "stdio.h"#define  TX_DATA_16                 (0x1234)
#define  TX_DATA_32                 (0x12345678)
#define  HALF_TX_BUFFER_SIZE        (256)
#define  TX_BUFFER_SIZE             (HALF_TX_BUFFER_SIZE*2)
uint32_t tx_buffer[TX_BUFFER_SIZE];/* USER CODE END 0 */I2S_HandleTypeDef hi2s3;
DMA_HandleTypeDef hdma_spi3_tx;/* I2S3 init function */
void MX_I2S3_Init(void)
{/* USER CODE BEGIN I2S3_Init 0 *///这里有一点需要注�???,i2s的DR�???16位的,�???以如果想发�??32位的数据,得写两次,//如果想发�???0x12345678,就得先发�???0x1234,再发�???0x5678(标准飞利浦格式是高位在前)//但是32位数组是小端�???,�???以就�???要重组一�???for(int i=0;i<TX_BUFFER_SIZE;i++){*(tx_buffer+i)= (TX_DATA_32<<16)|(TX_DATA_32>>16);}/* USER CODE END I2S3_Init 0 *//* USER CODE BEGIN I2S3_Init 1 *//* USER CODE END I2S3_Init 1 */hi2s3.Instance = SPI3;hi2s3.Init.Mode = I2S_MODE_MASTER_TX;hi2s3.Init.Standard = I2S_STANDARD_PHILIPS;hi2s3.Init.DataFormat = I2S_DATAFORMAT_32B;hi2s3.Init.MCLKOutput = I2S_MCLKOUTPUT_ENABLE;hi2s3.Init.AudioFreq = I2S_AUDIOFREQ_48K;hi2s3.Init.CPOL = I2S_CPOL_HIGH;hi2s3.Init.ClockSource = I2S_CLOCK_PLL;hi2s3.Init.FullDuplexMode = I2S_FULLDUPLEXMODE_DISABLE;if (HAL_I2S_Init(&hi2s3) != HAL_OK){Error_Handler();}/* USER CODE BEGIN I2S3_Init 2 *//* USER CODE END I2S3_Init 2 */}void HAL_I2S_MspInit(I2S_HandleTypeDef* i2sHandle)
{GPIO_InitTypeDef GPIO_InitStruct = {0};RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};if(i2sHandle->Instance==SPI3){/* USER CODE BEGIN SPI3_MspInit 0 *//* USER CODE END SPI3_MspInit 0 *//** Initializes the peripherals clock*/PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_I2S;PeriphClkInitStruct.PLLI2S.PLLI2SN = 192;PeriphClkInitStruct.PLLI2S.PLLI2SR = 2;if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK){Error_Handler();}/* I2S3 clock enable */__HAL_RCC_SPI3_CLK_ENABLE();__HAL_RCC_GPIOA_CLK_ENABLE();__HAL_RCC_GPIOC_CLK_ENABLE();/**I2S3 GPIO ConfigurationPA4     ------> I2S3_WSPC7     ------> I2S3_MCKPC10     ------> I2S3_CKPC12     ------> I2S3_SD*/GPIO_InitStruct.Pin = WCK_Pin;GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;GPIO_InitStruct.Pull = GPIO_NOPULL;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;GPIO_InitStruct.Alternate = GPIO_AF6_SPI3;HAL_GPIO_Init(WCK_GPIO_Port, &GPIO_InitStruct);GPIO_InitStruct.Pin = GPIO_PIN_7|BCK_Pin|DI_Pin;GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;GPIO_InitStruct.Pull = GPIO_NOPULL;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;GPIO_InitStruct.Alternate = GPIO_AF6_SPI3;HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);/* I2S3 DMA Init *//* SPI3_TX Init */hdma_spi3_tx.Instance = DMA1_Stream5;hdma_spi3_tx.Init.Channel = DMA_CHANNEL_0;hdma_spi3_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;hdma_spi3_tx.Init.PeriphInc = DMA_PINC_DISABLE;hdma_spi3_tx.Init.MemInc = DMA_MINC_ENABLE;hdma_spi3_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;hdma_spi3_tx.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;hdma_spi3_tx.Init.Mode = DMA_CIRCULAR;hdma_spi3_tx.Init.Priority = DMA_PRIORITY_LOW;hdma_spi3_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;if (HAL_DMA_Init(&hdma_spi3_tx) != HAL_OK){Error_Handler();}__HAL_LINKDMA(i2sHandle,hdmatx,hdma_spi3_tx);/* USER CODE BEGIN SPI3_MspInit 1 *//* USER CODE END SPI3_MspInit 1 */}
}void HAL_I2S_MspDeInit(I2S_HandleTypeDef* i2sHandle)
{if(i2sHandle->Instance==SPI3){/* USER CODE BEGIN SPI3_MspDeInit 0 *//* USER CODE END SPI3_MspDeInit 0 *//* Peripheral clock disable */__HAL_RCC_SPI3_CLK_DISABLE();/**I2S3 GPIO ConfigurationPA4     ------> I2S3_WSPC7     ------> I2S3_MCKPC10     ------> I2S3_CKPC12     ------> I2S3_SD*/HAL_GPIO_DeInit(WCK_GPIO_Port, WCK_Pin);HAL_GPIO_DeInit(GPIOC, GPIO_PIN_7|BCK_Pin|DI_Pin);/* I2S3 DMA DeInit */HAL_DMA_DeInit(i2sHandle->hdmatx);/* USER CODE BEGIN SPI3_MspDeInit 1 *//* USER CODE END SPI3_MspDeInit 1 */}
}/* USER CODE BEGIN 1 */int I2S_DMA_Start_Transmit()
{return HAL_I2S_Transmit_DMA(&hi2s3, (uint16_t *)tx_buffer, TX_BUFFER_SIZE);
}int I2S_DMA_Stop()
{return HAL_I2S_DMAStop(&hi2s3);
}/*** @brief  Tx Transfer Half completed callbacks* @param  hi2s pointer to a I2S_HandleTypeDef structure that contains*         the configuration information for I2S module* @retval None*/
void HAL_I2S_TxHalfCpltCallback(I2S_HandleTypeDef *hi2s)
{printf("%s\r\n",__func__);/* Prevent unused argument(s) compilation warning */UNUSED(hi2s);for(int i=0;i<HALF_TX_BUFFER_SIZE;i++){*(tx_buffer+i)+=1;}/* NOTE : This function Should not be modified, when the callback is needed,the HAL_I2S_TxHalfCpltCallback could be implemented in the user file*/
}/*** @brief  Tx Transfer completed callbacks* @param  hi2s pointer to a I2S_HandleTypeDef structure that contains*         the configuration information for I2S module* @retval None*/
void HAL_I2S_TxCpltCallback(I2S_HandleTypeDef *hi2s)
{printf("%s\r\n",__func__);/* Prevent unused argument(s) compilation warning */UNUSED(hi2s);for(int i=0;i<HALF_TX_BUFFER_SIZE;i++){*(tx_buffer+HALF_TX_BUFFER_SIZE+i)-=1;}/* NOTE : This function Should not be modified, when the callback is needed,the HAL_I2S_TxCpltCallback could be implemented in the user file*/
}/*** @brief  I2S error callbacks* @param  hi2s pointer to a I2S_HandleTypeDef structure that contains*         the configuration information for I2S module* @retval None*/
void HAL_I2S_ErrorCallback(I2S_HandleTypeDef *hi2s)
{/* Prevent unused argument(s) compilation warning */printf("HAL_I2S_Error\r\n");/* NOTE : This function Should not be modified, when the callback is needed,the HAL_I2S_ErrorCallback could be implemented in the user file*/
}/* USER CODE END 1 */

1. 其实这里使用了DMA双buffer的思路，但是我没有使用双buffer，而是一个buffer的前后部分。当TxHalfCplt的时候，我们去更新buffer前半部分数据，当TxCplt的时候，我们去更新buffer的后半部分数据。HAL库没有很好封装DMA双buffer的配置函数。
2. 关于DMA的buffer填充问题，I2S的DR寄存器是15位的，所以配置DMA的数据宽度也是16位的，如果I2S是32位的数据格式，那么需要写两次DR寄存器才能组一帧I2S数据，例如I2S想发送0x12345678，那么就得先发送0x1234，再发送0x5678（I2S飞利浦格式就是这样，高位在前），所以填充buffer的时候，也得按该顺序填充。
3. 关于全双工DMA的封装，HAL好像也没有很好的支持，等下次再介绍。。。

4、I2S实现DMA双buffer发送

我们如果看过HAL库接口的话，就应该知道。在dma_ex文件中封装了DMA双buffer的接口，但是在i2s文件或者i2s_ex中没有封装双buffer的接口。所以，我们打算仿照HAL_I2S_Transmit_DMA库函数实现一个函数。

/* USER CODE BEGIN 1 */
static void I2S_DMAM0TxHalfCplt(DMA_HandleTypeDef *hdma)
{I2S_HandleTypeDef *hi2s = (I2S_HandleTypeDef *)((DMA_HandleTypeDef *)hdma)->Parent; /* Derogation MISRAC2012-Rule-11.5 *//* Call user Tx half complete callback */printf("%s\r\n",__func__);
}static void I2S_DMAM0TxCplt(DMA_HandleTypeDef *hdma)
{I2S_HandleTypeDef *hi2s = (I2S_HandleTypeDef *)((DMA_HandleTypeDef *)hdma)->Parent; /* Derogation MISRAC2012-Rule-11.5 *//* Call user Tx complete callback */printf("%s\r\n",__func__);
}static void I2S_DMAM1TxHalfCplt(DMA_HandleTypeDef *hdma)
{I2S_HandleTypeDef *hi2s = (I2S_HandleTypeDef *)((DMA_HandleTypeDef *)hdma)->Parent; /* Derogation MISRAC2012-Rule-11.5 *//* Call user Tx half complete callback */printf("%s\r\n",__func__);
}static void I2S_DMAM1TxCplt(DMA_HandleTypeDef *hdma)
{I2S_HandleTypeDef *hi2s = (I2S_HandleTypeDef *)((DMA_HandleTypeDef *)hdma)->Parent; /* Derogation MISRAC2012-Rule-11.5 *//* Call user Tx complete callback */printf("%s\r\n",__func__);
}static void I2S_DMA_Error(DMA_HandleTypeDef *hdma)
{I2S_HandleTypeDef *hi2s = (I2S_HandleTypeDef *)((DMA_HandleTypeDef *)hdma)->Parent; /* Derogation MISRAC2012-Rule-11.5 */printf("%s\r\n",__func__);
}static HAL_StatusTypeDef HAL_I2S_Transmit_DMA_DBuffer(I2S_HandleTypeDef *hi2s, uint16_t *pData0,uint16_t *pData1, uint16_t Size)
{uint32_t tmpreg_cfgr;if ((pData0 == NULL) || (Size == 0U)){return  HAL_ERROR;}/* Process Locked */__HAL_LOCK(hi2s);if (hi2s->State != HAL_I2S_STATE_READY){__HAL_UNLOCK(hi2s);return HAL_BUSY;}/* Set state and reset error code */hi2s->State = HAL_I2S_STATE_BUSY_TX;hi2s->ErrorCode = HAL_I2S_ERROR_NONE;hi2s->pTxBuffPtr = pData0;tmpreg_cfgr = hi2s->Instance->I2SCFGR & (SPI_I2SCFGR_DATLEN | SPI_I2SCFGR_CHLEN);if ((tmpreg_cfgr == I2S_DATAFORMAT_24B) || (tmpreg_cfgr == I2S_DATAFORMAT_32B)){hi2s->TxXferSize = (Size << 1U);hi2s->TxXferCount = (Size << 1U);}else{hi2s->TxXferSize = Size;hi2s->TxXferCount = Size;}/* Set the I2S Tx DMA Half transfer complete callback */hi2s->hdmatx->XferHalfCpltCallback = I2S_DMAM0TxHalfCplt;/* Set the I2S Tx DMA transfer complete callback */hi2s->hdmatx->XferCpltCallback = I2S_DMAM0TxCplt;hi2s->hdmatx->XferM1HalfCpltCallback=I2S_DMAM1TxHalfCplt;//callbackhi2s->hdmatx->XferM1CpltCallback=I2S_DMAM1TxCplt;//callback/* Set the DMA error callback */hi2s->hdmatx->XferErrorCallback = I2S_DMA_Error;/* Enable the Tx DMA Stream/Channel */if (HAL_OK != HAL_DMAEx_MultiBufferStart_IT(hi2s->hdmatx,(uint32_t)hi2s->pTxBuffPtr,(uint32_t)&hi2s->Instance->DR,(uint32_t)pData1,hi2s->TxXferSize)){/* Update SPI error code */SET_BIT(hi2s->ErrorCode, HAL_I2S_ERROR_DMA);hi2s->State = HAL_I2S_STATE_READY;__HAL_UNLOCK(hi2s);return HAL_ERROR;}/* Check if the I2S is already enabled */if (HAL_IS_BIT_CLR(hi2s->Instance->I2SCFGR, SPI_I2SCFGR_I2SE)){/* Enable I2S peripheral */__HAL_I2S_ENABLE(hi2s);}/* Check if the I2S Tx request is already enabled */if (HAL_IS_BIT_CLR(hi2s->Instance->CR2, SPI_CR2_TXDMAEN)){/* Enable Tx DMA Request */SET_BIT(hi2s->Instance->CR2, SPI_CR2_TXDMAEN);}__HAL_UNLOCK(hi2s);return HAL_OK;
}

注意几点：

1. 这些函数还是写在i2s.c文件中。
2. 相比原函数，在函数参数上多了一个buffer地址。
3. 原函数中的回调函数都是本地函数，不供其他文件调用，所以全部重新定义在我们的本文件中。并且多了m1 buffer的回调函数。
4. DMA_Start函数更换为双buffer函数接口。其他的地方都没有改变。
   
   

5、全双工I2S实现

配置全双工Master模式，其实看源码就知道，当配置全双工的时候，用到了两个i2s外设。

如果我们配置i2s为Master_Tx，那么i2s_ex就会自动被配置为Slave_Rx。当然，这些在HAL库中都已经封装好了，我们使用起来还是不麻烦的。
但是，HAL库封装的函数很奇怪，所以我们仿照原库函数自己修改了一下。

static void I2S_DMARxHalfCplt(DMA_HandleTypeDef *hdma)
{printf("%s\r\n",__func__);
}static void I2S_DMARxCplt(DMA_HandleTypeDef *hdma)
{printf("%s\r\n",__func__);
}static void I2S_DMATxHalfCplt(DMA_HandleTypeDef *hdma)
{printf("%s\r\n",__func__);
}static void I2S_DMATxCplt(DMA_HandleTypeDef *hdma)
{printf("%s\r\n",__func__);
}static HAL_StatusTypeDef HAL_I2SEx_TransmitReceive_DMA_Modify(I2S_HandleTypeDef *hi2s,uint16_t *pTxData,uint16_t *pRxData,uint16_t Size)
{uint32_t *tmp = NULL;uint32_t tmp1 = 0U;HAL_StatusTypeDef errorcode = HAL_OK;if (hi2s->State != HAL_I2S_STATE_READY){errorcode = HAL_BUSY;goto error;}if ((pTxData == NULL) || (pRxData == NULL) || (Size == 0U)){return  HAL_ERROR;}/* Process Locked */__HAL_LOCK(hi2s);hi2s->pTxBuffPtr = pTxData;hi2s->pRxBuffPtr = pRxData;tmp1 = hi2s->Instance->I2SCFGR & (SPI_I2SCFGR_DATLEN | SPI_I2SCFGR_CHLEN);/* Check the Data format: When a 16-bit data frame or a 16-bit data frame extendedis selected during the I2S configuration phase, the Size parameter means the numberof 16-bit data length in the transaction and when a 24-bit data frame or a 32-bit dataframe is selected the Size parameter means the number of 16-bit data length. */if ((tmp1 == I2S_DATAFORMAT_24B) || (tmp1 == I2S_DATAFORMAT_32B)){hi2s->TxXferSize  = (Size << 1U);hi2s->TxXferCount = (Size << 1U);hi2s->RxXferSize  = (Size << 1U);hi2s->RxXferCount = (Size << 1U);}else{hi2s->TxXferSize  = Size;hi2s->TxXferCount = Size;hi2s->RxXferSize  = Size;hi2s->RxXferCount = Size;}hi2s->ErrorCode = HAL_I2S_ERROR_NONE;hi2s->State     = HAL_I2S_STATE_BUSY_TX_RX;/* Set the I2S Rx DMA Half transfer complete callback */hi2s->hdmarx->XferHalfCpltCallback = I2S_DMARxHalfCplt;/* Set the I2S Rx DMA transfer complete callback */hi2s->hdmarx->XferCpltCallback  = I2S_DMARxCplt;/* Set the I2S Rx DMA error callback */hi2s->hdmarx->XferErrorCallback = NULL;/* Set the I2S Tx DMA Half transfer complete callback as NULL */hi2s->hdmatx->XferHalfCpltCallback  = I2S_DMATxHalfCplt;/* Set the I2S Tx DMA transfer complete callback as NULL */hi2s->hdmatx->XferCpltCallback  = I2S_DMATxCplt;/* Set the I2S Tx DMA error callback */hi2s->hdmatx->XferErrorCallback = NULL;tmp1 = hi2s->Instance->I2SCFGR & SPI_I2SCFGR_I2SCFG;/* Check if the I2S_MODE_MASTER_TX or I2S_MODE_SLAVE_TX Mode is selected */if ((tmp1 == I2S_MODE_MASTER_TX) || (tmp1 == I2S_MODE_SLAVE_TX)){/* Enable the Rx DMA Stream */tmp = (uint32_t *)&pRxData;HAL_DMA_Start_IT(hi2s->hdmarx, (uint32_t)&I2SxEXT(hi2s->Instance)->DR, *(uint32_t *)tmp, hi2s->RxXferSize);/* Enable Rx DMA Request */SET_BIT(I2SxEXT(hi2s->Instance)->CR2, SPI_CR2_RXDMAEN);/* Enable the Tx DMA Stream */tmp = (uint32_t *)&pTxData;HAL_DMA_Start_IT(hi2s->hdmatx, *(uint32_t *)tmp, (uint32_t)&hi2s->Instance->DR, hi2s->TxXferSize);/* Enable Tx DMA Request */SET_BIT(hi2s->Instance->CR2, SPI_CR2_TXDMAEN);/* Check if the I2S is already enabled */if ((hi2s->Instance->I2SCFGR & SPI_I2SCFGR_I2SE) != SPI_I2SCFGR_I2SE){/* Enable I2Sext(receiver) before enabling I2Sx peripheral */__HAL_I2SEXT_ENABLE(hi2s);/* Enable I2S peripheral after the I2Sext */__HAL_I2S_ENABLE(hi2s);}}else{/* Check if Master Receiver mode is selected */if ((hi2s->Instance->I2SCFGR & SPI_I2SCFGR_I2SCFG) == I2S_MODE_MASTER_RX){/* Clear the Overrun Flag by a read operation on the SPI_DR register followed by a readaccess to the SPI_SR register. */__HAL_I2S_CLEAR_OVRFLAG(hi2s);}/* Enable the Tx DMA Stream */tmp = (uint32_t *)&pTxData;HAL_DMA_Start_IT(hi2s->hdmatx, *(uint32_t *)tmp, (uint32_t)&I2SxEXT(hi2s->Instance)->DR, hi2s->TxXferSize);/* Enable Tx DMA Request */SET_BIT(I2SxEXT(hi2s->Instance)->CR2, SPI_CR2_TXDMAEN);/* Enable the Rx DMA Stream */tmp = (uint32_t *)&pRxData;HAL_DMA_Start_IT(hi2s->hdmarx, (uint32_t)&hi2s->Instance->DR, *(uint32_t *)tmp, hi2s->RxXferSize);/* Enable Rx DMA Request */SET_BIT(hi2s->Instance->CR2, SPI_CR2_RXDMAEN);/* Check if the I2S is already enabled */if ((hi2s->Instance->I2SCFGR & SPI_I2SCFGR_I2SE) != SPI_I2SCFGR_I2SE){/* Enable I2Sext(transmitter) before enabling I2Sx peripheral */__HAL_I2SEXT_ENABLE(hi2s);/* Enable I2S peripheral before the I2Sext */__HAL_I2S_ENABLE(hi2s);}}error :__HAL_UNLOCK(hi2s);return errorcode;
}

相比原函数，我们就修改了一个地方，那就是把TX的回调函数也赋值了，其实这里不理解的地方有两个：

1. 为什么不给TX的回调函数赋值
2. 为什么RX的回调函数命名TxRx的回调函数
   我们在实验中直接将DI接在DO上了，最后看看调试结果
   
   最后，如果想在全双工中使用DMA双buffer，可以仿照上文中函数的修改即可，这里就不做示范了。