/* * stm32f10x_i2c.h * * Copyright (C) 2013 Houtouridis Christos * * All Rights Reserved. * * NOTICE: All information contained herein is, and remains * the property of Houtouridis Christos. The intellectual * and technical concepts contained herein are proprietary to * Houtouridis Christos and are protected by copyright law. * Dissemination of this information or reproduction of this material * is strictly forbidden unless prior written permission is obtained * from Houtouridis Christos. * * Author: Houtouridis Christos * Date: 4 ��� 2013 * */ #ifndef __STM32F10x_I2C_H__ #define __STM32F10x_I2C_H__ #ifdef __cplusplus extern "C" { #endif #include "stm32f10x.h" #include "stm32f10x_assert.h" /*============== User Defines ================*/ #define I2C_USE_IT (0) #define I2C_USE_SMBUS (0) #define I2C_USE_PEC (0) // I2C_Exported_Constants #define IS_I2C_ALL_PERIPH(PERIPH) (((PERIPH) == I2C1) || \ ((PERIPH) == I2C2)) // 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 #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 #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 #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 #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 #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_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 #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_NCAK_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_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 #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)) // I2C_flags_definition #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) #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)) /* * ==================================================================== * I2C Master Events (Events grouped in order of communication) * ==================================================================== */ /*! * \brief Communication start * * After sending the START condition (I2C_GenerateSTART() function) the master * has to wait for this event. It means that the Start condition has been correctly * released on the I2C bus (the bus is free, no other devices is communicating). * */ /* --EV5 */ #define I2C_EVENT_MASTER_MODE_SELECT ((uint32_t)0x00030001) /* BUSY, MSL and SB flag */ /*! * \brief Address Acknowledge * * After checking on EV5 (start condition correctly released on the bus), the * master sends the address of the slave(s) with which it will communicate * (I2C_Send7bitAddress() function, it also determines the direction of the communication: * Master transmitter or Receiver). Then the master has to wait that a slave acknowledges * his address. If an acknowledge is sent on the bus, one of the following events will * be set: * * 1) In case of Master Receiver (7-bit addressing): the I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED * event is set. * * 2) In case of Master Transmitter (7-bit addressing): the I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED * is set * * 3) In case of 10-Bit addressing mode, the master (just after generating the START * and checking on EV5) has to send the header of 10-bit addressing mode (I2C_SendData() * function). Then master should wait on EV9. It means that the 10-bit addressing * header has been correctly sent on the bus. Then master should send the second part of * the 10-bit address (LSB) using the function I2C_Send7bitAddress(). Then master * should wait for event EV6. * */ /* --EV6 */ #define I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED ((uint32_t)0x00070082) /* BUSY, MSL, ADDR, TXE and TRA flags */ #define I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED ((uint32_t)0x00030002) /* BUSY, MSL and ADDR flags */ /* --EV9 */ #define I2C_EVENT_MASTER_MODE_ADDRESS10 ((uint32_t)0x00030008) /* BUSY, MSL and ADD10 flags */ /*! * \brief Communication events * * If a communication is established (START condition generated and slave address * acknowledged) then the master has to check on one of the following events for * communication procedures: * * 1) Master Receiver mode: The master has to wait on the event EV7 then to read * the data received from the slave (I2C_ReceiveData() function). * * 2) Master Transmitter mode: The master has to send data (I2C_SendData() * function) then to wait on event EV8 or EV8_2. * These two events are similar: * - EV8 means that the data has been written in the data register and is * being shifted out. * - EV8_2 means that the data has been physically shifted out and output * on the bus. * In most cases, using EV8 is sufficient for the application. * Using EV8_2 leads to a slower communication but ensure more reliable test. * EV8_2 is also more suitable than EV8 for testing on the last data transmission * (before Stop condition generation). * * \note In case the user software does not guarantee that this event EV7 is * managed before the current byte end of transfer, then user may check on EV7 * and BTF flag at the same time (ie. (I2C_EVENT_MASTER_BYTE_RECEIVED | I2C_FLAG_BTF)). * In this case the communication may be slower. * */ /* Master RECEIVER mode -----------------------------*/ /* --EV7 */ #define I2C_EVENT_MASTER_BYTE_RECEIVED ((uint32_t)0x00030040) /* BUSY, MSL and RXNE flags */ /* --EV7_2 */ #define I2C_EVENT_MASTER_BYTE_TRANFERED ((uint32_t)0x00030044) /* Master TRANSMITTER mode --------------------------*/ /* --EV8 */ #define I2C_EVENT_MASTER_BYTE_TRANSMITTING ((uint32_t)0x00070080) /* TRA, BUSY, MSL, TXE flags */ /* --EV8_2 */ #define I2C_EVENT_MASTER_BYTE_TRANSMITTED ((uint32_t)0x00070084) /* TRA, BUSY, MSL, TXE and BTF flags */ /* * ======================================================================= * I2C Slave Events (Events grouped in order of communication) * ======================================================================= */ /*! * \brief Communication start events * * Wait on one of these events at the start of the communication. It means that * the I2C peripheral detected a Start condition on the bus (generated by master * device) followed by the peripheral address. The peripheral generates an ACK * condition on the bus (if the acknowledge feature is enabled through function * I2C_AcknowledgeConfig()) and the events listed above are set : * * 1) In normal case (only one address managed by the slave), when the address * sent by the master matches the own address of the peripheral (configured by * I2C_OwnAddress1 field) the I2C_EVENT_SLAVE_XXX_ADDRESS_MATCHED event is set * (where XXX could be TRANSMITTER or RECEIVER). * * 2) In case the address sent by the master matches the second address of the * peripheral (configured by the function I2C_OwnAddress2Config() and enabled * by the function I2C_DualAddressCmd()) the events I2C_EVENT_SLAVE_XXX_SECONDADDRESS_MATCHED * (where XXX could be TRANSMITTER or RECEIVER) are set. * * 3) In case the address sent by the master is General Call (address 0x00) and * if the General Call is enabled for the peripheral (using function I2C_GeneralCallCmd()) * the following event is set I2C_EVENT_SLAVE_GENERALCALLADDRESS_MATCHED. * */ /* --EV1 (all the events below are variants of EV1) */ /* 1) Case of One Single Address managed by the slave */ #define I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED ((uint32_t)0x00020002) /* BUSY and ADDR flags */ #define I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED ((uint32_t)0x00060082) /* TRA, BUSY, TXE and ADDR flags */ /* 2) Case of Dual address managed by the slave */ #define I2C_EVENT_SLAVE_RECEIVER_SECONDADDRESS_MATCHED ((uint32_t)0x00820000) /* DUALF and BUSY flags */ #define I2C_EVENT_SLAVE_TRANSMITTER_SECONDADDRESS_MATCHED ((uint32_t)0x00860080) /* DUALF, TRA, BUSY and TXE flags */ /* 3) Case of General Call enabled for the slave */ #define I2C_EVENT_SLAVE_GENERALCALLADDRESS_MATCHED ((uint32_t)0x00120000) /* GENCALL and BUSY flags */ /*! * \brief Communication events * * Wait on one of these events when EV1 has already been checked and: * * - Slave RECEIVER mode: * - EV2: When the application is expecting a data byte to be received. * - EV4: When the application is expecting the end of the communication: master * sends a stop condition and data transmission is stopped. * * - Slave Transmitter mode: * - EV3: When a byte has been transmitted by the slave and the application is expecting * the end of the byte transmission. The two events I2C_EVENT_SLAVE_BYTE_TRANSMITTED and * I2C_EVENT_SLAVE_BYTE_TRANSMITTING are similar. The second one can optionally be * used when the user software doesn't guarantee the EV3 is managed before the * current byte end of transfer. * - EV3_2: When the master sends a NACK in order to tell slave that data transmission * shall end (before sending the STOP condition). In this case slave has to stop sending * data bytes and expect a Stop condition on the bus. * * \note In case the user software does not guarantee that the event EV2 is * managed before the current byte end of transfer, then user may check on EV2 * and BTF flag at the same time (ie. (I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_BTF)). * In this case the communication may be slower. * */ /* Slave RECEIVER mode --------------------------*/ /* --EV2 */ #define I2C_EVENT_SLAVE_BYTE_RECEIVED ((uint32_t)0x00020040) /* BUSY and RXNE flags */ /* --EV4 */ #define I2C_EVENT_SLAVE_STOP_DETECTED ((uint32_t)0x00000010) /* STOPF flag */ /* Slave TRANSMITTER mode -----------------------*/ /* --EV3 */ #define I2C_EVENT_SLAVE_BYTE_TRANSMITTED ((uint32_t)0x00060084) /* TRA, BUSY, TXE and BTF flags */ #define I2C_EVENT_SLAVE_BYTE_TRANSMITTING ((uint32_t)0x00060080) /* TRA, BUSY and TXE flags */ /* --EV3_2 */ #define I2C_EVENT_SLAVE_ACK_FAILURE ((uint32_t)0x00000400) /* AF flag */ /*=========================== End of Events Description ==========================================*/ #define IS_I2C_EVENT(EVENT) (((EVENT) == I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED) || \ ((EVENT) == I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED) || \ ((EVENT) == I2C_EVENT_SLAVE_TRANSMITTER_SECONDADDRESS_MATCHED) || \ ((EVENT) == I2C_EVENT_SLAVE_RECEIVER_SECONDADDRESS_MATCHED) || \ ((EVENT) == I2C_EVENT_SLAVE_GENERALCALLADDRESS_MATCHED) || \ ((EVENT) == I2C_EVENT_SLAVE_BYTE_RECEIVED) || \ ((EVENT) == (I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_DUALF)) || \ ((EVENT) == (I2C_EVENT_SLAVE_BYTE_RECEIVED | I2C_FLAG_GENCALL)) || \ ((EVENT) == I2C_EVENT_SLAVE_BYTE_TRANSMITTED) || \ ((EVENT) == (I2C_EVENT_SLAVE_BYTE_TRANSMITTED | I2C_FLAG_DUALF)) || \ ((EVENT) == (I2C_EVENT_SLAVE_BYTE_TRANSMITTED | I2C_FLAG_GENCALL)) || \ ((EVENT) == I2C_EVENT_SLAVE_STOP_DETECTED) || \ ((EVENT) == I2C_EVENT_MASTER_MODE_SELECT) || \ ((EVENT) == I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED) || \ ((EVENT) == I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED) || \ ((EVENT) == I2C_EVENT_MASTER_BYTE_RECEIVED) || \ ((EVENT) == I2C_EVENT_MASTER_BYTE_TRANSMITTED) || \ ((EVENT) == I2C_EVENT_MASTER_BYTE_TRANSMITTING) || \ ((EVENT) == I2C_EVENT_MASTER_MODE_ADDRESS10) || \ ((EVENT) == I2C_EVENT_SLAVE_ACK_FAILURE)) #define IS_I2C_OWN_ADDRESS1(ADDRESS1) ((ADDRESS1) <= 0x3FF) #define IS_I2C_CLOCK_SPEED(SPEED) (((SPEED) >= 0x1) && ((SPEED) <= 400000)) /*===================== Data Types =========================*/ 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_OwnAddress; /*!< 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; /*====================== Exported Functions ===========================*/ void I2C_DeInit(I2C_TypeDef* I2Cx); 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_DMACmd(I2C_TypeDef* I2Cx, FunctionalState NewState); void I2C_DMALastTransferCmd(I2C_TypeDef* I2Cx, FunctionalState NewState); void I2C_GenerateSTART(I2C_TypeDef* I2Cx, FunctionalState NewState); void I2C_GenerateSTOP(I2C_TypeDef* I2Cx, FunctionalState NewState); 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); #if I2C_USE_IT == 1 void I2C_ITConfig(I2C_TypeDef* I2Cx, uint16_t I2C_IT, FunctionalState NewState); #endif void I2C_SendData(I2C_TypeDef* I2Cx, uint8_t Data); uint8_t I2C_ReceiveData(I2C_TypeDef* I2Cx); void I2C_Send7bitAddress(I2C_TypeDef* I2Cx, uint8_t Address, uint8_t I2C_Direction); uint16_t I2C_ReadRegister(I2C_TypeDef* I2Cx, uint8_t I2C_Register); void I2C_SoftwareResetCmd(I2C_TypeDef* I2Cx, FunctionalState NewState); void I2C_NACKPositionConfig(I2C_TypeDef* I2Cx, uint16_t I2C_NACKPosition); #if I2C_USE_SMBUS == 1 void I2C_SMBusAlertConfig(I2C_TypeDef* I2Cx, uint16_t I2C_SMBusAlert); #endif #if I2C_USE_PEC == 1 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); #endif //#if I2C_USE_PEC == 1 #if I2C_USE_SMBUS == 1 void I2C_ARPCmd(I2C_TypeDef* I2Cx, FunctionalState NewState); #endif void I2C_StretchClockCmd(I2C_TypeDef* I2Cx, FunctionalState NewState); void I2C_FastModeDutyCycleConfig(I2C_TypeDef* I2Cx, uint16_t I2C_DutyCycle); /*! * \brief **************************************************************************************** * * 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 * (RM0008). * - 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 I2Cx_ER_IRQHandler() * 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() 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 limitations of I2C_GetFlagStatus() function (see below). * The returned value could be compared to events already defined in the * library (stm32f10x_i2c.h) 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() 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); #if I2C_USE_IT == 1 ITStatus I2C_GetITStatus(I2C_TypeDef* I2Cx, uint32_t I2C_IT); void I2C_ClearITPendingBit(I2C_TypeDef* I2Cx, uint32_t I2C_IT); #endif #ifdef __cplusplus } #endif #endif /*__STM32F10x_I2C_H__ */ /*****END OF FILE****/