twi_primitives.c

adi black fin chip connect to cmos sensor

/*****************************************************************************
*	TWI_primitives.c
*   
*	Copyright (c) 2007 Analog Devices, Inc.  All Rights Reserved.
*   This software is proprietary to Analog Devices, Inc. and its
*	licensors.
*  
* 	CHANGES:  10/24/2007  1.00  - initial public release
*
*	SOFTWARE: 	VisualDSP++ 5.0 August 2007 Update
* 
* 	HARDWARE: 	BF561 EZ-Kit Lite Board Rev 1.4
*				Micron MTV9022 or MTV9032 Sensor
*
*
*	8 / 16 - bit read write routines making use of I2C_BF561_asm routines
*
*	DESCRIPTION:
* 
*	This file implements the TWI functions that will read/write a vector of 
*	8 or 16-bit values from/to a device, starting from an address.
*
*******************************************************************************/

extern volatile int SCCB_Control;
extern volatile void SCCB_Interface(void);
extern volatile int SCCB_In_Progress;
extern volatile int SCCB_Error;
extern volatile int SCCB_Word_Count;
extern volatile int SCCB_DataIn[];
extern volatile int SCCB_DataOut[];



unsigned int I2C_Reg_Write(bool addr_size_16, bool data_size_16, unsigned char TWIBase_Addr, unsigned short start_address, unsigned short* values, int Num_Transactions)
{
    unsigned int num_successful_transactions = 0;
	int i,j;
	
	unsigned int wr_addr = TWIBase_Addr;
	
	for (i=0; i<Num_Transactions; i++)
	{
	    j=0;
		SCCB_DataIn[j++] = wr_addr;									// base address
		if (addr_size_16) SCCB_DataIn[j++] = start_address >>8 ;	// high byte start address if applicable
		SCCB_DataIn[j++] = (start_address++) & 0xFF;					// low byte start address
		if (data_size_16) SCCB_DataIn[j++] = *(values + i) >> 8 ;	// high byte value if applicable
		SCCB_DataIn[j++] = *(values + i) & 0xFF;					// low byte value
		
		SCCB_Word_Count = j;

		SCCB_Control = 2;
		SCCB_Error = 0;
		SCCB_In_Progress = 1;
		
		SCCB_Interface();
		
		while(SCCB_In_Progress){};
		
		if (SCCB_Error != 0)
	 		break;		// error

		num_successful_transactions++;
		
	}
	return num_successful_transactions;
}			
			
unsigned int I2C_Reg_Read(bool addr_size_16, bool data_size_16, unsigned char TWIBase_Addr, unsigned short start_address, unsigned short* values, int Num_Transactions)
{
    unsigned int num_successful_transactions = 0;
	int i,j;
	
	unsigned int wr_addr = TWIBase_Addr;
	unsigned int rd_addr = wr_addr +1;
	
    j=0;
	SCCB_DataIn[j++] = wr_addr;									// base address
	if (addr_size_16) SCCB_DataIn[j++] = start_address >>8 ;	// high byte start address if applicable
	SCCB_DataIn[j++] = (start_address++) & 0xFF;				// low byte start address
	SCCB_DataIn[j++] = rd_addr;									// base address
		
		
	SCCB_Word_Count = j + (1 + (int)data_size_16) * Num_Transactions;

	SCCB_Control = 1;
	SCCB_Error = 0;
	SCCB_In_Progress = 1;

	SCCB_Interface();

	while(SCCB_In_Progress){};
	
	if (SCCB_Error == 0)
	{
	    num_successful_transactions = Num_Transactions; 	// no error
		for (i=0; i<Num_Transactions; i++)
		    if (data_size_16)
				*(values + i) = (SCCB_DataOut[2*i + 1] & 0xFF) + (SCCB_DataOut[2*i + 0] << 8);
			else
				*(values + i) = (SCCB_DataOut[i] & 0xFF);
	}
	else
		num_successful_transactions = 0;					// error	

	return num_successful_transactions;
}