twi_driver.h

The I2C driver use to control LCD momo that using I2C driver.

/********************** AVR155 : Accessing I2C LCD display using the AVR TWI ***********************

Device      : ATmega163

File name   : TWI_driver.h

Ver nr.     : 1.0

Description : Header file for TWI_driver.c

Author      : Asmund Saetre

Change log  : Created 01.05.2000  AS
 
;**************************************************************************************************/

/****************************************************************************
	Include Files
****************************************************************************/
#include "iom163.h"							//Change according to device
#include "ina90.h"

/****************************************************************************
	Struct definitions 
	tx_type is the data struct used as input to the "Send_to_TWI" function 
	and contain information about:
	Slave address
	Send or receive data to/from the slave
	Number of bytes to send or receive
	Pointer to a buffer containing the bytes to send, or to a buffer for the
	bytes to receive
****************************************************************************/
typedef struct
{
	unsigned char slave_adr;				//Slave address and W/R byte
	unsigned char size;						//Number of bytes to send or 
											//receive 	
	unsigned char *data_ptr;				//Pointer to the bytes to send
}tx_type;									//or pointerto RX buffer 

/****************************************************************************
	Function definitions
****************************************************************************/
extern unsigned char Send_to_TWI(tx_type*);	
extern unsigned char Send_byte(unsigned char);//Send one byte
extern unsigned char Get_byte(unsigned char*,char);	//Receive one byte
extern unsigned char Send_start(void);		//Send a Start condition
extern unsigned char Send_adr(unsigned char);//Send a Slave adr.
extern void Send_stop(void);				//Send a Stop condition
extern void Wait_TWI_int(void);				//Wait for TWI interrupt to occur
extern void Reset_TWI (void);				//Reset the TWI module and 
											//release the bus
extern char Init_TWI(void);					//Initilaize TWI

/****************************************************************************
Bit and byte definitions
****************************************************************************/
#define W 				0					//Data transfer direction WRITE
#define R 				1					//Data transfer direction READ
#define OWN_ADR 		60  				//Own slave address
#define SUCCESS 		0xFF

/****************************************************************************
TWI Stautus register definitions
****************************************************************************/
//General Master staus codes											
#define START		0x08					//START has been transmitted	
#define	REP_START	0x10					//Repeated START has been 
											//transmitted		
//Master Transmitter staus codes											
#define	MTX_ADR_ACK		0x18				//SLA+W has been tramsmitted
											//and ACK received	
#define	MTX_ADR_NACK	0x20				//SLA+W has been tramsmitted
											//and NACK received		
#define	MTX_DATA_ACK	0x28				//Data byte has been tramsmitted
											//and ACK received			
#define	MTX_DATA_NACK	0x30				//Data byte has been tramsmitted
											//and NACK received			
#define	MTX_ARB_LOST	0x38				//Arbitration lost in SLA+W or 
											//data bytes	
//Master Receiver staus codes	
#define	MRX_ARB_LOST	0x38				//Arbitration lost in SLA+R or 
											//NACK bit
#define	MRX_ADR_ACK		0x40				//SLA+R has been tramsmitted
											//and ACK received	
#define	MRX_ADR_NACK	0x48				//SLA+R has been tramsmitted
											//and NACK received		
#define	MRX_DATA_ACK	0x50				//Data byte has been received
											//and ACK tramsmitted
#define	MRX_DATA_NACK	0x58				//Data byte has been received
											//and NACK tramsmitted