00. 目录
01. I2C简介
I2C（内部集成电路）总线接口用作微控制器和 I2C 串行总线之间的接口。它提供多主模式功能，可以控制所有I2C总线特定的序列、协议、仲裁和时序。它支持标准和快速模式。它还与 SMBus 2.0 兼容。
它可以用于多种用途，包括 CRC 生成和验证、SMBus（系统管理总线）以及 PMBus（电源管理总线）。
根据器件的不同，可利用 DMA 功能来减轻 CPU 的工作量。
02. 相关类型
I2C Init structure
/**
* @brief I2C Init structure definition
*/
typedef struct
{
uint32_t I2C_ClockSpeed; /*!< Specifies the clock frequency.
This parameter must be set to a value lower than 400kHz */
uint16_t I2C_Mode; /*!< Specifies the I2C mode.
This parameter can be a value of @ref I2C_mode */
uint16_t I2C_DutyCycle; /*!< Specifies the I2C fast mode duty cycle.
This parameter can be a value of @ref I2C_duty_cycle_in_fast_mode */
uint16_t I2C_OwnAddress1; /*!< Specifies the first device own address.
This parameter can be a 7-bit or 10-bit address. */
uint16_t I2C_Ack; /*!< Enables or disables the acknowledgement.
This parameter can be a value of @ref I2C_acknowledgement */
uint16_t I2C_AcknowledgedAddress; /*!< Specifies if 7-bit or 10-bit address is acknowledged.
This parameter can be a value of @ref I2C_acknowledged_address */
}I2C_InitTypeDef;
I2C_Exported_Constants
/** @defgroup I2C_Exported_Constants
* @{
*/
#define IS_I2C_ALL_PERIPH(PERIPH) (((PERIPH) == I2C1) || \
((PERIPH) == I2C2) || \
((PERIPH) == I2C3))
/** @defgroup I2C_Digital_Filter
* @{
*/
#define IS_I2C_DIGITAL_FILTER(FILTER) ((FILTER) <= 0x0000000F)
/**
* @}
*/
I2C_mode
/** @defgroup I2C_mode
* @{
*/
#define I2C_Mode_I2C ((uint16_t)0x0000)
#define I2C_Mode_SMBusDevice ((uint16_t)0x0002)
#define I2C_Mode_SMBusHost ((uint16_t)0x000A)
#define IS_I2C_MODE(MODE) (((MODE) == I2C_Mode_I2C) || \
((MODE) == I2C_Mode_SMBusDevice) || \
((MODE) == I2C_Mode_SMBusHost))
I2C_duty_cycle_in_fast_mode
/** @defgroup I2C_duty_cycle_in_fast_mode
* @{
*/
#define I2C_DutyCycle_16_9 ((uint16_t)0x4000) /*!< I2C fast mode Tlow/Thigh = 16/9 */
#define I2C_DutyCycle_2 ((uint16_t)0xBFFF) /*!< I2C fast mode Tlow/Thigh = 2 */
#define IS_I2C_DUTY_CYCLE(CYCLE) (((CYCLE) == I2C_DutyCycle_16_9) || \
((CYCLE) == I2C_DutyCycle_2))
I2C_acknowledgement
/** @defgroup I2C_acknowledgement
* @{
*/
#define I2C_Ack_Enable ((uint16_t)0x0400)
#define I2C_Ack_Disable ((uint16_t)0x0000)
#define IS_I2C_ACK_STATE(STATE) (((STATE) == I2C_Ack_Enable) || \
((STATE) == I2C_Ack_Disable))
I2C_transfer_direction
/** @defgroup I2C_transfer_direction
* @{
*/
#define I2C_Direction_Transmitter ((uint8_t)0x00)
#define I2C_Direction_Receiver ((uint8_t)0x01)
#define IS_I2C_DIRECTION(DIRECTION) (((DIRECTION) == I2C_Direction_Transmitter) || \
((DIRECTION) == I2C_Direction_Receiver))
I2C_acknowledged_address
/** @defgroup I2C_acknowledged_address
* @{
*/
#define I2C_AcknowledgedAddress_7bit ((uint16_t)0x4000)
#define I2C_AcknowledgedAddress_10bit ((uint16_t)0xC000)
#define IS_I2C_ACKNOWLEDGE_ADDRESS(ADDRESS) (((ADDRESS) == I2C_AcknowledgedAddress_7bit) || \
((ADDRESS) == I2C_AcknowledgedAddress_10bit))
I2C_registers
/** @defgroup I2C_registers
* @{
*/
#define I2C_Register_CR1 ((uint8_t)0x00)
#define I2C_Register_CR2 ((uint8_t)0x04)
#define I2C_Register_OAR1 ((uint8_t)0x08)
#define I2C_Register_OAR2 ((uint8_t)0x0C)
#define I2C_Register_DR ((uint8_t)0x10)
#define I2C_Register_SR1 ((uint8_t)0x14)
#define I2C_Register_SR2 ((uint8_t)0x18)
#define I2C_Register_CCR ((uint8_t)0x1C)
#define I2C_Register_TRISE ((uint8_t)0x20)
#define IS_I2C_REGISTER(REGISTER) (((REGISTER) == I2C_Register_CR1) || \
((REGISTER) == I2C_Register_CR2) || \
((REGISTER) == I2C_Register_OAR1) || \
((REGISTER) == I2C_Register_OAR2) || \
((REGISTER) == I2C_Register_DR) || \
((REGISTER) == I2C_Register_SR1) || \
((REGISTER) == I2C_Register_SR2) || \
((REGISTER) == I2C_Register_CCR) || \
((REGISTER) == I2C_Register_TRISE))
I2C_NACK_position
/** @defgroup I2C_NACK_position
* @{
*/
#define I2C_NACKPosition_Next ((uint16_t)0x0800)
#define I2C_NACKPosition_Current ((uint16_t)0xF7FF)
#define IS_I2C_NACK_POSITION(POSITION) (((POSITION) == I2C_NACKPosition_Next) || \
((POSITION) == I2C_NACKPosition_Current))
I2C_SMBus_alert_pin_level
/** @defgroup I2C_SMBus_alert_pin_level
* @{
*/
#define I2C_SMBusAlert_Low ((uint16_t)0x2000)
#define I2C_SMBusAlert_High ((uint16_t)0xDFFF)
#define IS_I2C_SMBUS_ALERT(ALERT) (((ALERT) == I2C_SMBusAlert_Low) || \
((ALERT) == I2C_SMBusAlert_High))
I2C_PEC_position
/** @defgroup I2C_PEC_position
* @{
*/
#define I2C_PECPosition_Next ((uint16_t)0x0800)
#define I2C_PECPosition_Current ((uint16_t)0xF7FF)
#define IS_I2C_PEC_POSITION(POSITION) (((POSITION) == I2C_PECPosition_Next) || \
((POSITION) == I2C_PECPosition_Current))
I2C_interrupts_definition
/** @defgroup I2C_interrupts_definition
* @{
*/
#define I2C_IT_BUF ((uint16_t)0x0400)
#define I2C_IT_EVT ((uint16_t)0x0200)
#define I2C_IT_ERR ((uint16_t)0x0100)
#define IS_I2C_CONFIG_IT(IT) ((((IT) & (uint16_t)0xF8FF) == 0x00) && ((IT) != 0x00))
I2C_interrupts_definition
/** @defgroup I2C_interrupts_definition
* @{
*/
#define I2C_IT_SMBALERT ((uint32_t)0x01008000)
#define I2C_IT_TIMEOUT ((uint32_t)0x01004000)
#define I2C_IT_PECERR ((uint32_t)0x01001000)
#define I2C_IT_OVR ((uint32_t)0x01000800)
#define I2C_IT_AF ((uint32_t)0x01000400)
#define I2C_IT_ARLO ((uint32_t)0x01000200)
#define I2C_IT_BERR ((uint32_t)0x01000100)
#define I2C_IT_TXE ((uint32_t)0x06000080)
#define I2C_IT_RXNE ((uint32_t)0x06000040)
#define I2C_IT_STOPF ((uint32_t)0x02000010)
#define I2C_IT_ADD10 ((uint32_t)0x02000008)
#define I2C_IT_BTF ((uint32_t)0x02000004)
#define I2C_IT_ADDR ((uint32_t)0x02000002)
#define I2C_IT_SB ((uint32_t)0x02000001)
#define IS_I2C_CLEAR_IT(IT) ((((IT) & (uint16_t)0x20FF) == 0x00) && ((IT) != (uint16_t)0x00))
#define IS_I2C_GET_IT(IT) (((IT) == I2C_IT_SMBALERT) || ((IT) == I2C_IT_TIMEOUT) || \
((IT) == I2C_IT_PECERR) || ((IT) == I2C_IT_OVR) || \
((IT) == I2C_IT_AF) || ((IT) == I2C_IT_ARLO) || \
((IT) == I2C_IT_BERR) || ((IT) == I2C_IT_TXE) || \
((IT) == I2C_IT_RXNE) || ((IT) == I2C_IT_STOPF) || \
((IT) == I2C_IT_ADD10) || ((IT) == I2C_IT_BTF) || \
((IT) == I2C_IT_ADDR) || ((IT) == I2C_IT_SB))
SR2 register flags
/**
* @brief SR2 register flags
*/
#define I2C_FLAG_DUALF ((uint32_t)0x00800000)
#define I2C_FLAG_SMBHOST ((uint32_t)0x00400000)
#define I2C_FLAG_SMBDEFAULT ((uint32_t)0x00200000)
#define I2C_FLAG_GENCALL ((uint32_t)0x00100000)
#define I2C_FLAG_TRA ((uint32_t)0x00040000)
#define I2C_FLAG_BUSY ((uint32_t)0x00020000)
#define I2C_FLAG_MSL ((uint32_t)0x00010000)
SR1 register flags
/**
* @brief SR1 register flags
*/
#define I2C_FLAG_SMBALERT ((uint32_t)0x10008000)
#define I2C_FLAG_TIMEOUT ((uint32_t)0x10004000)
#define I2C_FLAG_PECERR ((uint32_t)0x10001000)
#define I2C_FLAG_OVR ((uint32_t)0x10000800)
#define I2C_FLAG_AF ((uint32_t)0x10000400)
#define I2C_FLAG_ARLO ((uint32_t)0x10000200)
#define I2C_FLAG_BERR ((uint32_t)0x10000100)
#define I2C_FLAG_TXE ((uint32_t)0x10000080)
#define I2C_FLAG_RXNE ((uint32_t)0x10000040)
#define I2C_FLAG_STOPF ((uint32_t)0x10000010)
#define I2C_FLAG_ADD10 ((uint32_t)0x10000008)
#define I2C_FLAG_BTF ((uint32_t)0x10000004)
#define I2C_FLAG_ADDR ((uint32_t)0x10000002)
#define I2C_FLAG_SB ((uint32_t)0x10000001)
#define IS_I2C_CLEAR_FLAG(FLAG) ((((FLAG) & (uint16_t)0x20FF) == 0x00) && ((FLAG) != (uint16_t)0x00))
#define IS_I2C_GET_FLAG(FLAG) (((FLAG) == I2C_FLAG_DUALF) || ((FLAG) == I2C_FLAG_SMBHOST) || \
((FLAG) == I2C_FLAG_SMBDEFAULT) || ((FLAG) == I2C_FLAG_GENCALL) || \
((FLAG) == I2C_FLAG_TRA) || ((FLAG) == I2C_FLAG_BUSY) || \
((FLAG) == I2C_FLAG_MSL) || ((FLAG) == I2C_FLAG_SMBALERT) || \
((FLAG) == I2C_FLAG_TIMEOUT) || ((FLAG) == I2C_FLAG_PECERR) || \
((FLAG) == I2C_FLAG_OVR) || ((FLAG) == I2C_FLAG_AF) || \
((FLAG) == I2C_FLAG_ARLO) || ((FLAG) == I2C_FLAG_BERR) || \
((FLAG) == I2C_FLAG_TXE) || ((FLAG) == I2C_FLAG_RXNE) || \
((FLAG) == I2C_FLAG_STOPF) || ((FLAG) == I2C_FLAG_ADD10) || \
((FLAG) == I2C_FLAG_BTF) || ((FLAG) == I2C_FLAG_ADDR) || \
((FLAG) == I2C_FLAG_SB))
03. 相关函数
/* Function used to set the I2C configuration to the default reset state *****/
void I2C_DeInit(I2C_TypeDef* I2Cx);
/* Initialization and Configuration functions *********************************/
void I2C_Init(I2C_TypeDef* I2Cx, I2C_InitTypeDef* I2C_InitStruct);
void I2C_StructInit(I2C_InitTypeDef* I2C_InitStruct);
void I2C_Cmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_DigitalFilterConfig(I2C_TypeDef* I2Cx, uint16_t I2C_DigitalFilter);
void I2C_AnalogFilterCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_GenerateSTART(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_GenerateSTOP(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_Send7bitAddress(I2C_TypeDef* I2Cx, uint8_t Address, uint8_t I2C_Direction);
void I2C_AcknowledgeConfig(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_OwnAddress2Config(I2C_TypeDef* I2Cx, uint8_t Address);
void I2C_DualAddressCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_GeneralCallCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_SoftwareResetCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_StretchClockCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_FastModeDutyCycleConfig(I2C_TypeDef* I2Cx, uint16_t I2C_DutyCycle);
void I2C_NACKPositionConfig(I2C_TypeDef* I2Cx, uint16_t I2C_NACKPosition);
void I2C_SMBusAlertConfig(I2C_TypeDef* I2Cx, uint16_t I2C_SMBusAlert);
void I2C_ARPCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
/* Data transfers functions ***************************************************/
void I2C_SendData(I2C_TypeDef* I2Cx, uint8_t Data);
uint8_t I2C_ReceiveData(I2C_TypeDef* I2Cx);
/* PEC management functions ***************************************************/
void I2C_TransmitPEC(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_PECPositionConfig(I2C_TypeDef* I2Cx, uint16_t I2C_PECPosition);
void I2C_CalculatePEC(I2C_TypeDef* I2Cx, FunctionalState NewState);
uint8_t I2C_GetPEC(I2C_TypeDef* I2Cx);
/* DMA transfers management functions *****************************************/
void I2C_DMACmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_DMALastTransferCmd(I2C_TypeDef* I2Cx, FunctionalState NewState);
/* Interrupts, events and flags management functions **************************/
uint16_t I2C_ReadRegister(I2C_TypeDef* I2Cx, uint8_t I2C_Register);
void I2C_ITConfig(I2C_TypeDef* I2Cx, uint16_t I2C_IT, FunctionalState NewState);
/*
===============================================================================
I2C State Monitoring Functions
===============================================================================
This I2C driver provides three different ways for I2C state monitoring
depending on the application requirements and constraints:
1. Basic state monitoring (Using I2C_CheckEvent() function)
-----------------------------------------------------------
It compares the status registers (SR1 and SR2) content to a given event
(can be the combination of one or more flags).
It returns SUCCESS if the current status includes the given flags
and returns ERROR if one or more flags are missing in the current status.
- When to use
- This function is suitable for most applications as well as for startup
activity since the events are fully described in the product reference
manual (RM0090).
- It is also suitable for users who need to define their own events.
- Limitations
- If an error occurs (ie. error flags are set besides to the monitored
flags), the I2C_CheckEvent() function may return SUCCESS despite
the communication hold or corrupted real state.
In this case, it is advised to use error interrupts to monitor
the error events and handle them in the interrupt IRQ handler.
Note
For error management, it is advised to use the following functions:
- I2C_ITConfig() to configure and enable the error interrupts (I2C_IT_ERR).
- I2Cx_ER_IRQHandler() which is called when the error interrupt occurs.
Where x is the peripheral instance (I2C1, I2C2 ...)
- I2C_GetFlagStatus() or I2C_GetITStatus() to be called into the
I2Cx_ER_IRQHandler() function in order to determine which error occurred.
- I2C_ClearFlag() or I2C_ClearITPendingBit() and/or I2C_SoftwareResetCmd()
and/or I2C_GenerateStop() in order to clear the error flag and source
and return to correct communication status.
2. Advanced state monitoring (Using the function I2C_GetLastEvent())
--------------------------------------------------------------------
Using the function I2C_GetLastEvent() which returns the image of both status
registers in a single word (uint32_t) (Status Register 2 value is shifted left
by 16 bits and concatenated to Status Register 1).
- When to use
- This function is suitable for the same applications above but it
allows to overcome the mentioned limitation of I2C_GetFlagStatus()
function.
- The returned value could be compared to events already defined in
this file or to custom values defined by user.
This function is suitable when multiple flags are monitored at the
same time.
- At the opposite of I2C_CheckEvent() function, this function allows
user to choose when an event is accepted (when all events flags are
set and no other flags are set or just when the needed flags are set
like I2C_CheckEvent() function.
- Limitations
- User may need to define his own events.
- Same remark concerning the error management is applicable for this
function if user decides to check only regular communication flags
(and ignores error flags).
3. Flag-based state monitoring (Using the function I2C_GetFlagStatus())
-----------------------------------------------------------------------
Using the function I2C_GetFlagStatus() which simply returns the status of
one single flag (ie. I2C_FLAG_RXNE ...).
- When to use
- This function could be used for specific applications or in debug
phase.
- It is suitable when only one flag checking is needed (most I2C
events are monitored through multiple flags).
- Limitations:
- When calling this function, the Status register is accessed.
Some flags are cleared when the status register is accessed.
So checking the status of one Flag, may clear other ones.
- Function may need to be called twice or more in order to monitor
one single event.
*/
/*
===============================================================================
1. Basic state monitoring
===============================================================================
*/
ErrorStatus I2C_CheckEvent(I2C_TypeDef* I2Cx, uint32_t I2C_EVENT);
/*
===============================================================================
2. Advanced state monitoring
===============================================================================
*/
uint32_t I2C_GetLastEvent(I2C_TypeDef* I2Cx);
/*
===============================================================================
3. Flag-based state monitoring
===============================================================================
*/
FlagStatus I2C_GetFlagStatus(I2C_TypeDef* I2Cx, uint32_t I2C_FLAG);
void I2C_ClearFlag(I2C_TypeDef* I2Cx, uint32_t I2C_FLAG);
ITStatus I2C_GetITStatus(I2C_TypeDef* I2Cx, uint32_t I2C_IT);
void I2C_ClearITPendingBit(I2C_TypeDef* I2Cx, uint32_t I2C_IT);
04. 结构体封装
/**
* @brief Inter-integrated Circuit Interface
*/
typedef struct
{
__IO uint16_t CR1; /*!< I2C Control register 1, Address offset: 0x00 */
uint16_t RESERVED0; /*!< Reserved, 0x02 */
__IO uint16_t CR2; /*!< I2C Control register 2, Address offset: 0x04 */
uint16_t RESERVED1; /*!< Reserved, 0x06 */
__IO uint16_t OAR1; /*!< I2C Own address register 1, Address offset: 0x08 */
uint16_t RESERVED2; /*!< Reserved, 0x0A */
__IO uint16_t OAR2; /*!< I2C Own address register 2, Address offset: 0x0C */
uint16_t RESERVED3; /*!< Reserved, 0x0E */
__IO uint16_t DR; /*!< I2C Data register, Address offset: 0x10 */
uint16_t RESERVED4; /*!< Reserved, 0x12 */
__IO uint16_t SR1; /*!< I2C Status register 1, Address offset: 0x14 */
uint16_t RESERVED5; /*!< Reserved, 0x16 */
__IO uint16_t SR2; /*!< I2C Status register 2, Address offset: 0x18 */
uint16_t RESERVED6; /*!< Reserved, 0x1A */
__IO uint16_t CCR; /*!< I2C Clock control register, Address offset: 0x1C */
uint16_t RESERVED7; /*!< Reserved, 0x1E */
__IO uint16_t TRISE; /*!< I2C TRISE register, Address offset: 0x20 */
uint16_t RESERVED8; /*!< Reserved, 0x22 */
__IO uint16_t FLTR; /*!< I2C FLTR register, Address offset: 0x24 */
uint16_t RESERVED9; /*!< Reserved, 0x26 */
} I2C_TypeDef;
05. 预留
06. 附录
6.1 【STM32】STM32系列教程汇总