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关于HAL库代码stm32f1xx_hal_uart.c代码分析，不看肯定后悔

602 HAL库

问答对人有帮助，内容完整，我也想知道答案 0 STM32串口通信原理是什么？关于HAL库代码stm32f1xx_hal_uart.c代码分析，不看肯定后悔 0
2021-12-9 07:29:30　　评论淘帖0 邀请回答您可以邀请以下用户，快速回答问题 × heks 该类别下有 50 个回答。邀请回答 hgimtk 该类别下有 44 个回答。邀请回答新星之火12138 该类别下有 42 个回答。邀请回答 wang21cj 该类别下有 41 个回答。邀请回答 chm5 该类别下有 40 个回答。邀请回答 hjfjsdgfjdsf 该类别下有 37 个回答。邀请回答 fdjslkjd 该类别下有 35 个回答。邀请回答 uvysdfydad 该类别下有 35 个回答。邀请回答 werywer 该类别下有 35 个回答。邀请回答 h1654155957.9520 该类别下有 35 个回答。邀请回答 jenny042 该类别下有 34 个回答。邀请回答 dfzvzs 该类别下有 34 个回答。邀请回答维生素B2 该类别下有 34 个回答。邀请回答凤毛麟角该类别下有 34 个回答。邀请回答 hfgdzc 该类别下有 33 个回答。邀请回答 ggfvxv 该类别下有 33 个回答。邀请回答刘洋该类别下有 33 个回答。邀请回答 meihuacg 该类别下有 33 个回答。邀请回答尼克wo 该类别下有 32 个回答。邀请回答储蓄叛逆该类别下有 32 个回答。邀请回答举报刘英相关推荐 • STM32CubeMX+HAL库调试串口的经验总结，不看肯定后悔 1333 • 为什么HAL库的stm32f3xx_hal_rcc.c中的定义前有_weak修饰 3447 • 请问STM32的HAL库stm32f4xx_hal_msp.c文件函数HAL_MspInit有什么作用 13924 • STM32HAL移植json解析器开源库的知识点汇总，不看肯定后悔 1578 • stm32启动汇编代码分析介绍，不看肯定后悔 569 • 关于3C2440启动代码注释不看肯定后悔 554 • startup_stm32f40_41xxx.s启动代码分析，不看肯定后悔 774 • 如何使用HAL执行idle_line中断呢？ 181 • 请问stm32l4xx_hal_uart.c文件中的_HAL_LOCK(huart)函数有什么用 3018 • 关于Arduino的认识与思考不看肯定后悔 1778 1个回答

答案对人有帮助，有参考价值 0 在USART的发送端有2个寄存器，一个是程序可以看到的USART_DR寄存器,另一个是程序看不到的移位寄存器,对应USART数据发送有两个标志，一个是TXE=发送数据寄存器空(单字节)，另一个是TC=发送结束(多字节)。当USART_DR中的1字节数据传送到移位寄存器后，TXE被置位，此时移位寄存器开始向TX信号线按位传输数据，但因为TDR已经变空，程序可以把下一个要发送的1字节数据(操作USART_DR)写入TDR中，而不必等到移位寄存器中所有位(共8位)发送结束，所有多个字节均发送结束时(最后1字节中送出停止位后)硬件会将TC标志置位。　　另一方面，在刚刚初始化好USART还没有发送任何数据时，也会有TXE标志，因为这时发送数据寄存器是空的(故通常程序串口初始化时不打开此中断，否则频繁进入TXE中断)。而发送完成TCIE和IDLEIE则必须等发送1次数据后，才会有此中断产生，故一开始打开TCIE和IDLEIE中断没有关系。当然一开始必须要打开RXNEIE中断（接收数据），TXEIE和TCIE的意义很简单，TXEIE允许在TXE标志为'1'时产生中断，而TCIE允许在TC标志为'1'时产生中断。　　至于什么时候使用哪个标志，需要根据你的需要自己决定。但我认为TXE允许程序有更充裕的时间填写TDR寄存器，保证发送的数据流不间断。TC可以让程序知道发送结束的确切时间，有利于程序控制外部数据流的时序。 TXE--写寄存器DR清零 RXNE--读寄存器DR清零，也可软件手动清零 TC-- 读/写寄存器DR清零，也可软件手动清零 IDLE--需要软件清除，__HAL_UART_CLEAR_IDLEFLAG[HAL] 串口收发数据都是以1个字节为单位，如果是阻塞轮询模式，是while多少字节数，如果是中断，则每收发1个字节，则进入1次中断； HAL库代码分析： HAL_StatusTypeDef HAL_UART_Transmit(UART_HandleTypeDef huart, uint8_t pData, uint16_t Size, uint32_t Timeout) {//阻塞串口发送函数 uint16_t* tmp; uint32_t tickstart = 0U; /* Check that a Tx process is not already ongoing / if(huart->gState == HAL_UART_STATE_READY) { if((pData == NULL) \|\| (Size == 0U)) { return HAL_ERROR; } / Process Locked / __HAL_LOCK(huart); huart->ErrorCode = HAL_UART_ERROR_NONE; huart->gState = HAL_UART_STATE_BUSY_TX; / Init tickstart for timeout managment / tickstart = HAL_GetTick(); huart->TxXferSize = Size;//发送的数据量(多少字节) huart->TxXferCount = Size;//还剩余的要发送的数据量 while(huart->TxXferCount > 0U)//阻塞模式,while循环 { huart->TxXferCount--;//每发完1个字节，剩余要发送数据量减1 if(huart->Init.WordLength == UART_WORDLENGTH_9B) {//带有校验 if(UART_WaitOnFlagUntilTimeout(huart, UART_FLAG_TXE, RESET, tickstart, Timeout) != HAL_OK) { return HAL_TIMEOUT; } tmp = (uint16_t) pData; huart->Instance->DR = (tmp & (uint16_t)0x01FF); if(huart->Init.Parity == UART_PARITY_NONE) {//校验正确 pData +=2U; } else { pData +=1U; } } else {//不带校验 if(UART_WaitOnFlagUntilTimeout(huart, UART_FLAG_TXE, RESET, tickstart, Timeout) != HAL_OK) {//上面函数作用是保证发送寄存器里的数据为空(UART_FLAG_TXE置位) return HAL_TIMEOUT; } huart->Instance->DR = (pData++ & (uint8_t)0xFF);//发送寄存器写入数据，UART_FLAG_TXE复位【待数据全部移到发送移位寄存器时，UART_FLAG_TXE置位，故前面超时等待】 } } if(UART_WaitOnFlagUntilTimeout(huart, UART_FLAG_TC, RESET, tickstart, Timeout) != HAL_OK) {//上面函数作用是保证全部传输完成，UART_FLAG_TC置1，否则也认为传输失败，双重保证！ return HAL_TIMEOUT; } /* At end of Tx process, restore huart->gState to Ready / huart->gState = HAL_UART_STATE_READY; / Process Unlocked / __HAL_UNLOCK(huart); return HAL_OK; } else { return HAL_BUSY; } } HAL_StatusTypeDef HAL_UART_Transmit_IT(UART_HandleTypeDef huart, uint8_t pData, uint16_t Size) {//串口中断方式发送数据* /* Check that a Tx process is not already ongoing / if(huart->gState == HAL_UART_STATE_READY) { if((pData == NULL) \|\| (Size == 0U)) { return HAL_ERROR; } / Process Locked / __HAL_LOCK(huart); huart->pTxBuffPtr = pData;//指向待发送缓冲区首地址 huart->TxXferSize = Size;//发送的数据量(多少字节) huart->TxXferCount = Size;//还剩余的要发送的数据量 huart->ErrorCode = HAL_UART_ERROR_NONE; huart->gState = HAL_UART_STATE_BUSY_TX; / Process Unlocked / __HAL_UNLOCK(huart); / Enable the UART Transmit data register empty Interrupt / __HAL_UART_ENABLE_IT(huart, UART_IT_TXE);//此处仅仅打开TXE中断，【此时还未开始发送数据，发送缓冲区TDR为空，将进入到串口中断函数-stm32f1xx_it.c的void USARTx_IRQHandler(void) x=1,2,3...】 return HAL_OK; } else { return HAL_BUSY; } } void HAL_UART_IRQHandler(UART_HandleTypeDef huart) {//串口中断函数回调函数 uint32_t isrflags = READ_REG(huart->Instance->SR); uint32_t cr1its = READ_REG(huart->Instance->CR1); uint32_t cr3its = READ_REG(huart->Instance->CR3); uint32_t errorflags = 0x00U; uint32_t dmarequest = 0x00U; /* If no error occurs / errorflags = (isrflags & (uint32_t)(USART_SR_PE \| USART_SR_FE \| USART_SR_ORE \| USART_SR_NE)); if(errorflags == RESET) {//无任何串口错误时 / UART in mode Receiver -------------------------------------------------/ if(((isrflags & USART_SR_RXNE) != RESET) && ((cr1its & USART_CR1_RXNEIE) != RESET)) {//接收中断标志置位且中断使能 UART_Receive_IT(huart);//串口中断接收处理函数 return; } } / If some errors occur / if((errorflags != RESET) && (((cr3its & USART_CR3_EIE) != RESET) \|\| ((cr1its & (USART_CR1_RXNEIE \| USART_CR1_PEIE)) != RESET))) { / UART parity error interrupt occurred ----------------------------------/ if(((isrflags & USART_SR_PE) != RESET) && ((cr1its & USART_CR1_PEIE) != RESET)) {//校验出错且校验中断使能 huart->ErrorCode \|= HAL_UART_ERROR_PE; } / UART noise error interrupt occurred -----------------------------------/ if(((isrflags & USART_SR_NE) != RESET) && ((cr3its & USART_CR3_EIE) != RESET)) { huart->ErrorCode \|= HAL_UART_ERROR_NE; } / UART frame error interrupt occurred -----------------------------------/ if(((isrflags & USART_SR_FE) != RESET) && ((cr3its & USART_CR3_EIE) != RESET)) { huart->ErrorCode \|= HAL_UART_ERROR_FE; } / UART Over-Run interrupt occurred --------------------------------------/ if(((isrflags & USART_SR_ORE) != RESET) && ((cr3its & USART_CR3_EIE) != RESET)) { huart->ErrorCode \|= HAL_UART_ERROR_ORE; } / Call UART Error Call back function if need be --------------------------/ if(huart->ErrorCode != HAL_UART_ERROR_NONE) { / UART in mode Receiver -----------------------------------------------/ if(((isrflags & USART_SR_RXNE) != RESET) && ((cr1its & USART_CR1_RXNEIE) != RESET)) { UART_Receive_IT(huart); } / If Overrun error occurs, or if any error occurs in DMA mode reception, consider error as blocking / dmarequest = HAL_IS_BIT_SET(huart->Instance->CR3, USART_CR3_DMAR); if(((huart->ErrorCode & HAL_UART_ERROR_ORE) != RESET) \|\| dmarequest) { / Blocking error : transfer is aborted Set the UART state ready to be able to start again the process, Disable Rx Interrupts, and disable Rx DMA request, if ongoing / UART_EndRxTransfer(huart); / Disable the UART DMA Rx request if enabled / if(HAL_IS_BIT_SET(huart->Instance->CR3, USART_CR3_DMAR)) { CLEAR_BIT(huart->Instance->CR3, USART_CR3_DMAR); / Abort the UART DMA Rx channel / if(huart->hdmarx != NULL) { / Set the UART DMA Abort callback : will lead to call HAL_UART_ErrorCallback() at end of DMA abort procedure / huart->hdmarx->XferAbortCallback = UART_DMAAbortOnError; if(HAL_DMA_Abort_IT(huart->hdmarx) != HAL_OK) { / Call Directly XferAbortCallback function in case of error / huart->hdmarx->XferAbortCallback(huart->hdmarx); } } else { / Call user error callback / HAL_UART_ErrorCallback(huart);//异常回调函数可增加提示 } } else { / Call user error callback / HAL_UART_ErrorCallback(huart); } } else { / Non Blocking error : transfer could go on. Error is notified to user through user error callback / HAL_UART_ErrorCallback(huart); huart->ErrorCode = HAL_UART_ERROR_NONE; } } return; } / End if some error occurs / / UART in mode Transmitter ------------------------------------------------/ if(((isrflags & USART_SR_TXE) != RESET) && ((cr1its & USART_CR1_TXEIE) != RESET)) {//接回上面提到的TXEIE中断被触发，接着执行到此处【每发1个字节执行到此处】，下面有UART_Transmit_IT详细分析 UART_Transmit_IT(huart); return; } / UART in mode Transmitter end --------------------------------------------/ if(((isrflags & USART_SR_TC) != RESET) && ((cr1its & USART_CR1_TCIE) != RESET)) {//如果上面的多个字节都发送完毕，则此刻TC标志被置位，如果中断使能，将进入到下面函数执行 UART_EndTransmit_IT(huart);//__HAL_UART_DISABLE_IT(huart, UART_IT_TC);关闭TC中断,还有个回调空白函数-发送完成函数HAL_UART_TxCpltCallback供用户增加想要的功能 return; } } static HAL_StatusTypeDef UART_Transmit_IT(UART_HandleTypeDef huart) { uint16_t* tmp; /* Check that a Tx process is ongoing / if(huart->gState == HAL_UART_STATE_BUSY_TX) { if(huart->Init.WordLength == UART_WORDLENGTH_9B) {//带有校验处理 tmp = (uint16_t) huart->pTxBuffPtr; huart->Instance->DR = (uint16_t)(tmp & (uint16_t)0x01FF); if(huart->Init.Parity == UART_PARITY_NONE) { huart->pTxBuffPtr += 2U; } else { huart->pTxBuffPtr += 1U; } } else {//不带校验发送 huart->Instance->DR = (uint8_t)(huart->pTxBuffPtr++ & (uint8_t)0x00FF);//TDR发送寄存器写入数据，TXE标志被清零，待发送寄存器中的1字节数据被全部转移到发送移位寄存器中，此刻发送寄存器又为空，TXE中断再次被触发，由再次进入到串口中断函数，进入到此处执行，故而实现数据连续不间断发送【pTxBuffPtr++指向待发送下1字节数据】 } if(--huart->TxXferCount == 0U) {//待发送的字节数为0时，表示数据发送完毕 /* Disable the UART Transmit Complete Interrupt / __HAL_UART_DISABLE_IT(huart, UART_IT_TXE);//必须关闭TXE中断，否则会一直进入，毕竟没数据发送时，TDR一直为空 / Enable the UART Transmit Complete Interrupt / __HAL_UART_ENABLE_IT(huart, UART_IT_TC);//打开发送完成中断，因为数据发送完毕，TC标志将置位，将再次进入到串口中断函数里执行，此时执行到前面的UART_EndTransmit_IT函数 } return HAL_OK; } else { return HAL_BUSY; } } HAL_StatusTypeDef HAL_UART_Receive(UART_HandleTypeDef huart, uint8_t pData, uint16_t Size, uint32_t Timeout) {//串口阻塞接收函数【中断未打开】* uint16_t* tmp; uint32_t tickstart = 0U; /* Check that a Rx process is not already ongoing / if(huart->RxState == HAL_UART_STATE_READY) { if((pData == NULL) \|\| (Size == 0U)) { return HAL_ERROR; } / Process Locked / __HAL_LOCK(huart); huart->ErrorCode = HAL_UART_ERROR_NONE; huart->RxState = HAL_UART_STATE_BUSY_RX; / Init tickstart for timeout managment / tickstart = HAL_GetTick(); huart->RxXferSize = Size;//接收的最大数据量字节数【因是阻塞模式，故事先知道接收多少字节数据】 huart->RxXferCount = Size;//还剩余的要接收的数据量字节数 / Check the remain data to be received / while(huart->RxXferCount > 0U) { huart->RxXferCount--;//每接收完1字节，则减1 if(huart->Init.WordLength == UART_WORDLENGTH_9B) {//带有校验 if(UART_WaitOnFlagUntilTimeout(huart, UART_FLAG_RXNE, RESET, tickstart, Timeout) != HAL_OK) { return HAL_TIMEOUT; } tmp = (uint16_t)pData; if(huart->Init.Parity == UART_PARITY_NONE) { tmp = (uint16_t)(huart->Instance->DR & (uint16_t)0x01FF); pData +=2U; } else { tmp = (uint16_t)(huart->Instance->DR & (uint16_t)0x00FF); pData +=1U; } } else {//不带校验的接收处理 if(UART_WaitOnFlagUntilTimeout(huart, UART_FLAG_RXNE, RESET, tickstart, Timeout) != HAL_OK) {//等待RXNE标志置位，等待时间Timeout【特别说明，如果传递的Size大于实际收到的数据，则肯定会超时】，如果被置位，表示接收寄存器RDR收到数据 return HAL_TIMEOUT;//如果未被置位，则超时退出 } if(huart->Init.Parity == UART_PARITY_NONE) { pData++ = (uint8_t)(huart->Instance->DR & (uint8_t)0x00FF);//从DR读取数据，该操作会将RXNE标志复位，前面置位，故而形成循环，保证数据正确接收 } else { pData++ = (uint8_t)(huart->Instance->DR & (uint8_t)0x007F); } } } /* At end of Rx process, restore huart->RxState to Ready / huart->RxState = HAL_UART_STATE_READY; / Process Unlocked / __HAL_UNLOCK(huart); return HAL_OK; } else { return HAL_BUSY; } } HAL_StatusTypeDef HAL_UART_Receive_IT(UART_HandleTypeDef huart, uint8_t pData, uint16_t Size) {//串口中断接收函数 / Check that a Rx process is not already ongoing / if(huart->RxState == HAL_UART_STATE_READY) { if((pData == NULL) \|\| (Size == 0U)) { return HAL_ERROR; } / Process Locked / __HAL_LOCK(huart); huart->pRxBuffPtr = pData;//接收的数据缓存指针 huart->RxXferSize = Size;//接收的最大数据量字节数 huart->RxXferCount = Size;//还剩余的要接收的数据量字节数 huart->ErrorCode = HAL_UART_ERROR_NONE; huart->RxState = HAL_UART_STATE_BUSY_RX; / Process Unlocked / __HAL_UNLOCK(huart); / Enable the UART Parity Error Interrupt / __HAL_UART_ENABLE_IT(huart, UART_IT_PE);//校验错误中断使能 / Enable the UART Error Interrupt: (Frame error, noise error, overrun error) / __HAL_UART_ENABLE_IT(huart, UART_IT_ERR);//错误中断使能-帧错误,噪错误，满溢错误 / Enable the UART Data Register not empty Interrupt / __HAL_UART_ENABLE_IT(huart, UART_IT_RXNE);//接收中断使能【如果串口收到数据，则进入到串口处理函数HAL_UART_IRQHandler】 return HAL_OK; } else { return HAL_BUSY; } } 如果串口收到数据，则进入到串口处理函数HAL_UART_IRQHandler的下面部分执行 if(((isrflags & USART_SR_RXNE) != RESET) && ((cr1its & USART_CR1_RXNEIE) != RESET)) {//打开串口中断，且有数据收到-RXNE被置位 UART_Receive_IT(huart); return; } static HAL_StatusTypeDef UART_Receive_IT(UART_HandleTypeDef huart) { uint16_t* tmp; /* Check that a Rx process is ongoing / if(huart->RxState == HAL_UART_STATE_BUSY_RX) { if(huart->Init.WordLength == UART_WORDLENGTH_9B) {//带有校验 tmp = (uint16_t) huart->pRxBuffPtr; if(huart->Init.Parity == UART_PARITY_NONE) { tmp = (uint16_t)(huart->Instance->DR & (uint16_t)0x01FF); huart->pRxBuffPtr += 2U; } else { tmp = (uint16_t)(huart->Instance->DR & (uint16_t)0x00FF); huart->pRxBuffPtr += 1U; } } else {//不带校验 if(huart->Init.Parity == UART_PARITY_NONE) { huart->pRxBuffPtr++ = (uint8_t)(huart->Instance->DR & (uint8_t)0x00FF);//接收数据寄存器RDR被读取【保存数据到接收buf，并指向下一个】，RXNE标志复位。【当下1字节数据8位全部都从接收移位寄存器转移到接收数据寄存器RDR后，RXNE再次被置位，将再次触发RXNE中断，再次到此处执行，如此循环直到收完全部数据】 } else { huart->pRxBuffPtr++ = (uint8_t)(huart->Instance->DR & (uint8_t)0x007F); } } if(--huart->RxXferCount == 0U) {//收完全部数据后 /* Disable the IRDA Data Register not empty Interrupt / __HAL_UART_DISABLE_IT(huart, UART_IT_RXNE);//关闭RXNE中断 / Disable the UART Parity Error Interrupt / __HAL_UART_DISABLE_IT(huart, UART_IT_PE);//关闭校验错误中断 / Disable the UART Error Interrupt: (Frame error, noise error, overrun error) / __HAL_UART_DISABLE_IT(huart, UART_IT_ERR);//关闭错误中断 / Rx process is completed, restore huart->RxState to Ready */ huart->RxState = HAL_UART_STATE_READY; HAL_UART_RxCpltCallback(huart);//接收完成中断回调函数，用户可以再这里做操作 return HAL_OK; } return HAL_OK; } else { return HAL_BUSY; } }

2021-12-9 10:04:56 评论举报刘桂珍