STM32F10 x_USART.doc

21.1 USART寄存器结构.34321.2 USART库函数.344No函数名描述1USART_DeInit将外设USARTx寄存器重设为缺省值2USART_Init根据USART_InitStruct中指定的参数初始化外设USARTx寄存器3USART_StructInit把USART_InitStruct中的每一个参数按缺省值填入4USART_Cmd使能或失能USART外设5USART_ITConfig使能或失能指定的USART中断6USART_DMACmd使能或者失能指定USART的DMA请求7USART_SetAddress设置USART节点的地址8USART_WakeUpConfig选择USART的唤醒方式9USART_ReceiverWakeUpCmd检查USART是否处于静默模式10USART_LINBreakDetectLengthConfig设置USART LIN中断检测长度11USART_LINCmd使能或失能USARTx的LIN模式12USART_SendData通过外设USARTx发送单个数据13USART_ReceiveData返回USARTx最近接收到的数据14USART_SendBreak发送中断字15USART_SetGuardTime设置指定的USART保护时间16USART_SetPrescaler设置USART时钟预分频17USART_SmartCardCmd使能或失能指定USART的智能卡模式18USART_SmartCardNackCmd使能或失能NACK传输19USART_HalfDuplexCmd使能或失能USART半双工模式20USART_IrDAConfig设置USART IrDA模式21USART_IrDACmd使能或失能USART IrDA模式22USART_GetFlagStatus检查指定的USART标志位设置与否23USART_ClearFlag清除USARTx的待处理标志位24USART_GetITStatus检查指定的USART中断发生与否25USART_ClearITPendingBit清除USARTx的中断待处理位26USART_ClockInitUSART时钟配置27USART_ClockStructInitUSART时钟结构体缺省值初始化21通用同步异步收发器（USART） 通用同步异步收发器（USART）提供一种灵活的方法来与使用工业标准NRZ异步数据格式的外部设备之间进全双工数据交换。USART用分数波特发生器提供宽范围的波特选择。它支持同步单向通信和半双工单线通信。它也支持LIN(局部互连网)，智能卡协议和IrDA(红外数据组织)SIR ENDEC 规范，以及调制解调器(CTS/RTS)操作。它还允许多处器通信。使用多缓冲器配置的DMA方式，可以实现高速数据通信。 Section 21.1 USART寄存器结构描述了固件函数库所使用的数据结构，Section 21.2 固件库函数介绍了函数库里的所有函数。21.1 USART寄存器结构 USART寄存器结构，USART_TypeDeff，在文件stm32f0x_map.h中定义如下： typedef struct vu16 SR; u16 RESERVED1; vu16 DR; u16 RESERVED2; vu16 BRR; u16 RESERVED3; vu16 CR1; u16 RESERVED4; vu16 CR2; u16 RESERVED5; vu16 CR3; u16 RESERVED6; vu16 GTPR; u16 RESERVED7; USART_TypeDef;Table 704.例举了USART所有寄存器 Table 704. USART寄存器寄存器描述SRUSART状态寄存器DRUSART数据寄存器BRRUSART波特率寄存器CR1USART控制寄存器1 CR2USART控制寄存器2 CR3USART控制寄存器3 GTPRUSART保护时间和预分频寄存器3 个USART外设声明于文件：. #define PERIPH_BASE (u32)0x40000000) #define APB1PERIPH_BASE PERIPH_BASE #define APB2PERIPH_BASE (PERIPH_BASE + 0x10000) #define AHBPERIPH_BASE (PERIPH_BASE + 0x20000)#define USART1_BASE (APB2PERIPH_BASE + 0x3800)#define USART2_BASE (APB1PERIPH_BASE + 0x4400)#define USART3_BASE (APB1PERIPH_BASE + 0x4800) #ifndef DEBUG . #ifdef _USART1 #define USART1 (USART_TypeDef *) USART1_BASE)#endif /*_USART1 */ #ifdef _USART2 #define USART2 (USART_TypeDef *) USART2_BASE) #endif /*_USART2 */ #ifdef _USART3 #define USART3 (USART_TypeDef *) USART3_BASE) #endif /*_USART3 */ . #else /* DEBUG */ . #ifdef _USART1 EXT USART_TypeDef *USART1; #endif /*_USART1 */ #ifdef _USART2 EXT USART_TypeDef *USART2; #endif /*_USART2 */ #ifdef _USART3 EXT USART_TypeDef *USART3; #endif /*_USART3 */ . #endif 使用Debug模式时，初始化指针USART1, USART2和USART3于文件stm2f10x_lib.c： . #ifdef _USART1 USART1 = (USART_TypeDef *) USART1_BASE; #endif /*_USART1 */ #ifdef _USART2 USART2 = (USART_TypeDef *) USART2_BASE; #endif /*_USART2 */ #ifdef _USART3 USART3 = (USART_TypeDef *) USART3_BASE; #endif /*_USART3 */ . 为了访问USART寄存器，_USART，_USART1, _USART2和_USART3必须在文件中定义如下：. #define _USART #define _USART1 #define _USART2 #define _USART3 21.2 USART库函数 USART库函数【见首页】。【01】函数USART_DeInit Table 706. 函数USART_DeInit函数名USART_DeInit 函数原形void USART_DeInit(USART_TypeDef* USARTx)功能描述将外设USARTx寄存器重设为缺省值输入参数USARTx：x可以是1/2/3，来选择USART外设输出参数无返回值无先决条件无被调用函数RCC_APB2PeriphResetCmd() RCC_APB1PeriphResetCmd() 例： /* Resets the USART1 registers to their default reset value */ USART_DeInit(USART1); 函数原型如下：void USART_DeInit(USART_TypeDef* USARTx) /* Check the parameters */ assert_param(IS_USART_ALL_PERIPH(USARTx);/三个USART，两个UART switch (*(u32*)&USARTx) case USART1_BASE: RCC_APB2PeriphResetCmd(RCC_APB2Periph_USART1, ENABLE); RCC_APB2PeriphResetCmd(RCC_APB2Periph_USART1, DISABLE); break; case USART2_BASE: RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2, ENABLE); RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART2, DISABLE); break; case USART3_BASE: RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART3, ENABLE); RCC_APB1PeriphResetCmd(RCC_APB1Periph_USART3, DISABLE); break; case UART4_BASE: RCC_APB1PeriphResetCmd(RCC_APB1Periph_UART4, ENABLE); RCC_APB1PeriphResetCmd(RCC_APB1Periph_UART4, DISABLE); break; case UART5_BASE: RCC_APB1PeriphResetCmd(RCC_APB1Periph_UART5, ENABLE); RCC_APB1PeriphResetCmd(RCC_APB1Periph_UART5, DISABLE); break; default: break; 【02】函数USART_Init Table 707. 函数USART_Init函数名USART_Init 函数原形void USART_Init(USART_TypeDef* USARTx, USART_InitTypeDef* USART_InitStruct)功能描述根据USART_InitStruct中指定的参数初始化外设USARTx寄存器输入参数1USARTx：x=1/2/3，来选择USART外设输入参数2USART_InitStruct：指向结构USART_InitTypeDef的指针，包含了外设USART的配置信息。输出参数无返回值无先决条件无被调用函数无USART_InitTypeDef structure USART_InitTypeDef定义于文件stm2f10x_usart.h：typedef struct u32 USART_BaudRate; u16 USART_WordLength; u16 USART_StopBits; u16 USART_Parity; u16 USART_HardwareFlowControl; u16 USART_Mode; u16 USART_Clock; u16 USART_CPOL;u16 USART_CPHA; u16 USART_LastBit; USART_InitTypeDef; Table 708. 描述了结构USART_InitTypeDef在同步和异步模式下使用的不同成员。 Table 708. USART_InitTypeDef成员USART模式对比成员异步模式同步模式USART_BaudRateXXUSART_WordLengthXXUSART_StopBitsXXUSART_ParityXXUSART_HardwareFlowControlXXUSART_ModeXXUSART_ClockXUSART_CPOLXUSART_CPHAXUSART_LastBitXUSART_BaudRate USART_BaudRate：该成员设置了USART传输的波特率，波特率可以由以下公式计算： IntegerDivider = (APBClock) / (16 * (USART_InitStruct-USART_BaudRate) FractionalDivider = (IntegerDivider - (u32) IntegerDivider) * 16) + 0.5 其取值范围为：0 BaudRate USART_BaudRate); assert_param(IS_USART_WORD_LENGTH(USART_InitStruct-USART_WordLength); assert_param(IS_USART_STOPBITS(USART_InitStruct-USART_StopBits); assert_param(IS_USART_PARITY(USART_InitStruct-USART_Parity); assert_param(IS_USART_MODE(USART_InitStruct-USART_Mode); assert_param(IS_USART_HARDWARE_FLOW_CONTROL(USART_InitStruct-USART_HardwareFlowControl); /* The hardware flow control is available only for USART1, USART2 and USART3 */ assert_param(IS_USART_PERIPH_HFC(USARTx, USART_InitStruct-USART_HardwareFlowControl); usartxbase = (*(u32*)&USARTx);/*- USART CR2 Configuration -*/ tmpreg = USARTx-CR2; /* Clear STOP13:12 bits */ tmpreg &= CR2_STOP_CLEAR_Mask; /* Configure the USART Stop Bits, Clock, CPOL, CPHA and LastBit -*/ /* Set STOP13:12 bits according to USART_StopBits value */ tmpreg |= (u32)USART_InitStruct-USART_StopBits; /* Write to USART CR2 */ USARTx-CR2 = (u16)tmpreg;/*- USART CR1 Configuration -*/ tmpreg = USARTx-CR1; /* Clear M, PCE, PS, TE and RE bits */ tmpreg &= CR1_CLEAR_Mask; /* Configure the USART Word Length, Parity and mode - */ /* Set the M bits according to USART_WordLength value */ /* Set PCE and PS bits according to USART_Parity value */ /* Set TE and RE bits according to USART_Mode value */ tmpreg |= (u32)USART_InitStruct-USART_WordLength | USART_InitStruct-USART_Parity | USART_InitStruct-USART_Mode; /* Write to USART CR1 */ USARTx-CR1 = (u16)tmpreg;/*- USART CR3 Configuration -*/ tmpreg = USARTx-CR3; /* Clear CTSE and RTSE bits */ tmpreg &= CR3_CLEAR_Mask; /* Configure the USART HFC -*/ /* Set CTSE and RTSE bits according to USART_HardwareFlowControl value */ tmpreg |= USART_InitStruct-USART_HardwareFlowControl; /* Write to USART CR3 */ USARTx-CR3 = (u16)tmpreg;/*- USART BRR Configuration -*/ /* Configure the USART Baud Rate -*/ RCC_GetClocksFreq(&RCC_ClocksStatus); if (usartxbase = USART1_BASE) apbclock = RCC_ClocksStatus.PCLK2_Frequency; else apbclock = RCC_ClocksStatus.PCLK1_Frequency; /* Determine the integer part */ integerdivider = (0x19 * apbclock) / (0x04 * (USART_InitStruct-USART_BaudRate); tmpreg = (integerdivider / 0x64) 0x04); tmpreg |= (fractionaldivider * 0x10) + 0x32) / 0x64) & (u8)0x0F); /* Write to USART BRR */ USARTx-BRR = (u16)tmpreg;【03】函数USART_StructInit Table 718. 函数USART_StructInit函数名USART_StructInit 函数原形void USART_StructInit(USART_InitTypeDef* USART_InitStruct)功能描述把USART_InitStruct中的每一个参数按缺省值填入输入参数USART_InitStruct：指向结构USART_InitTypeDef的指针，待初始化输出参数无返回值无先决条件无被调用函数无Table 719. 给出了USART_InitStruct各个成员的缺省值 Table 719. USART_InitStruct缺省值(#define Val 参看函数【2】)成员缺省值#define ValUSART_BaudRate9600USART_WordLengthUSART_WordLength_8bUSART_StopBitsUSART_StopBits_1USART_ParityUSART_Parity_NoUSART_HardwareFlowControlUSART_HardwareFlowControl_NoneUSART_ModeUSART_Mode_Rx | USART_Mode_TxUSART_ClockUSART_Clock_DisableUSART_CPOLUSART_CPOL_LowUSART_CPHAUSART_CPHA_1EdgeUSART_LastBitUSART_LastBit_Disable例： /* The following example illustrates how to initialize a USART_InitTypeDef structure */ USART_InitTypeDef USART_InitStructure; USART_StructInit(&USART_InitStructure); 函数原型如下：void USART_StructInit(USART_InitTypeDef* USART_InitStruct) /* USART_InitStruct members default value */ USART_InitStruct-USART_BaudRate = 9600; USART_InitStruct-USART_WordLength = USART_WordLength_8b; USART_InitStruct-USART_StopBits = USART_StopBits_1; USART_InitStruct-USART_Parity = USART_Parity_No ; USART_InitStruct-USART_Mode = USART_Mode_Rx | USART_Mode_Tx; USART_InitStruct-USART_HardwareFlowControl = USART_HardwareFlowControl_None; 【04】函数USART_Cmd Table 720. 函数USART_Cmd 函数名USART_ Cmd函数原形void USART_Cmd(USART_TypeDef* USARTx, FunctionalState NewState) 功能描述使能或失能USART外设输入参数1USARTx：x=1/2/3，来选择USART外设输入参数2NewState: 外设USARTx的新状态（ENABLE或DISABLE）输出参数无返回值无先决条件无被调用函数无例： /* Enable the USART1 */ USART_Cmd(USART1, ENABLE); 函数原型如下：void USART_Cmd(USART_TypeDef* USARTx, FunctionalState NewState) /* Check the parameters */ assert_param(IS_USART_ALL_PERIPH(USARTx); assert_param(IS_FUNCTIONAL_STATE(NewState); if (NewState != DISABLE) /* Enable the selected USART by setting the UE bit in the CR1 register */ USARTx-CR1 |= CR1_UE_Set; else /* Disable the selected USART by clearing the UE bit in the CR1 register */ USARTx-CR1 &= CR1_UE_Reset; 【05】函数USART_ITConfig Table 721. 函数USART_ITConfig函数名USART_ITConfig 函数原形void USART_ITConfig(USART_TypeDef* USARTx, u16 USART_IT, FunctionalState NewState) 功能描述使能或失能指定的USART中断输入参数1USARTx：x=1/2/3，来选择USART外设输入参数2USART_IT：待使能或者失能的USART中断源输入参数3NewState：USARTx中断的新状态（ENABLE或DISABLE）输出参数无返回值无先决条件无被调用函数无USART_IT：输入参数USART_IT使能或者失能USART的中断。可以取下表的一个或者多个取值的组合作为该参数的值。 Table 722. USART_IT值 BitUSART_IT描述#define#Val5#Val的意义9USART_IT_CTSCTS中断0x096A受控于CR3.bitA黑体部分表示IT标志在SR中的位置；蓝色部分（5的结果）表示IT是由哪个CRx控制的；绿色部分表示IT在CRx中的第N位。8USART_IT_LBDLIN中断检测中断0x0846受控于CR2.bit67USART_IT_TXE发送中断0x0727受控于CR1.bit7-46USART_IT_TC传输完成中断0x06265USART_IT_RXNE接收中断0x05254USART_IT_IDLE空闲总线中断0x04243USART_IT_ORE过载错误0x0360受控于CR3.bit02USART_IT_NE噪声错误0x02601USART_IT_FE帧错误错误0x01600USART_IT_PE奇偶错误中断0x0028受控于CR1.bit8*USART_IT_ERR错误中断0x0060CR3.bit0,控制SR.ORENEFE例： /* Enables the USART1 transmit interrupt */ USART_ITConfig(USART1, USART_IT_Transmit ENABLE); 函数原型如下：void USART_ITConfig(USART_TypeDef* USARTx, u16 USART_IT, FunctionalState NewState) u32 usartreg = 0x00, itpos = 0x00, itmask = 0x00; u32 usartxbase = 0x00; /* Check the parameters */ assert_param(IS_USART_ALL_PERIPH(USARTx); assert_param(IS_USART_CONFIG_IT(USART_IT); assert_param(IS_USART_PERIPH_IT(USARTx, USART_IT);/* The CTS interrupt is not available for UART4 and UART5 */ assert_param(IS_FUNCTIONAL_STATE(NewState); usartxbase = (*(u32*)&(USARTx); /* Get the USART register index */ usartreg = (u8)USART_IT) 0x05); /* Get the interrupt position */ itpos = USART_IT & IT_Mask;/IT_Mask = 0x001F itmask = (u32)0x01) CR3 |= USART_DMAReq; else /* Disable the DMA transfer for selected requests by clearing the DMAT and/or DMAR bits in the USART CR3 register */ USARTx-CR3 &= (u16)USART_DMAReq; 【07】函数USART_SetAddress Table 725. 函数USART_SetAddress函数名USART_SetAddress 函数原形void USART_SetAddress(USART_TypeDef* USARTx, u8 USART_Address) 功能描述设置USART节点的地址输入参数1USARTx：x=1/2/3，来选择USART外设输入参数2USART_Address：提示USART节点的地址。输出参数无返回值无先决条件无被调用函数无例： /* Sets the USART2 address node to 0x5 */ USART_SetAddress(USART2, 0x5); 函数原型如下：void USART_SetAddress(USART_TypeDef* USARTx, u8 USART_Address) /* Check the parameters */ assert_param(IS_USART_ALL_PERIPH(USARTx); assert_param(IS_USART_ADDRESS(USART_Address); /#de