i2c state machine.h

来自「I2C的源程序」· C头文件 代码 · 共 92 行

#ifndef I2C_STATE_MACHINE
	#define I2C_STATE_MACHINE

//--------------------------------------------------------------------------//
// Header files																//
//--------------------------------------------------------------------------//
#include "I2C Pin Access.h"

//--------------------------------------------------------------------------//
// Symbolic constants														//
//--------------------------------------------------------------------------//
#define I2C_READ_WRITE_BIT	0x01
#define I2C_ACK_VALUE		0xff

//--------------------------------------------------------------------------//
// Type definitions															//
//--------------------------------------------------------------------------//
// states of the I2C main state machine
typedef enum
{
	I2C_IDLE,
	I2C_START,
	I2C_STOP,
	I2C_WRITE_DEV_ADDR,
	I2C_WRITE_REG_ADDR,
	I2C_WRITE_DATA,
	I2C_READ_DATA,
	I2C_CHECK_ACK,
	I2C_SEND_ACK
} t_I2C_Main_States;

// states of the I2C subordinate state machines
typedef enum
{
	I2C_SET_LOW_SCL,
	I2C_SET_LOW_SDA,
	I2C_SET_LOW_SCL_SDA,
	I2C_SET_HIGH_SCL,
	I2C_SET_HIGH_SDA,
	I2C_SET_HIGH_SCL_SDA,
	I2C_SET_LEVEL_SDA,
	I2C_SET_SDA_INPUT,
	I2C_SET_SDA_OUTPUT,
	I2C_READ_SDA
} t_I2C_Sub_States;

// used for configuring t_I2C_Transfer.Bit_Count
enum t_I2C_Word_Lengths
{
	I2C_DEVICE_LENGTH		= 8,
	I2C_REGISTER_LENGTH		= 8,
	I2C_DATA_LENGTH			= 8,
	I2C_ACK_LENGTH			= 1
};

// used in I2C main SM to determine SM_Next_State
typedef enum
{
	I2C_SM_Write_Path,
	I2C_SM_Read_Path
} t_I2C_SM_Path;

// structure defining a complete I2C message
typedef struct
{
	char Dev_Addr;
	char Reg_Addr;
	char Data;
} t_I2C_Message;

// structure holding one byte to be transmitted/received via I2C
typedef struct
{
	char Byte;
	char Bit_Count;
} t_I2C_Transfer;

// public I2C state machine functions
void I2C_Setup(t_I2C_Message *New_Message);
bool I2C_Advance_State(void);
bool I2C_Get_Error_Status(void);

// private I2C state machine functions
bool I2C_Execute_START(void);
bool I2C_Execute_STOP(void);
bool I2C_Execute_WRITE(void);
bool I2C_Execute_READ(void);
bool I2C_Execute_CHECK_ACK(void);

#endif											// I2C_STATE_MACHINE