//----------------------------------------------------------------------------
// I2C.C
//----------------------------------------------------------------------------
// I2C peripheral programming
//----------------------------------------------------------------------------
// Copyright SGS Thomson Microelectronics  !  Version alpha  !  Jan 1st, 1995
//----------------------------------------------------------------------------

//----------------------------------------------------------------------------
//                               Include files
//----------------------------------------------------------------------------
#include "stdefs.h"
#include "aal.h"
#include "debug.h"

//----------------------------------------------------------------------------
//                              Private Types
//----------------------------------------------------------------------------

//----------------------------------------------------------------------------
//                            Private Constants
//----------------------------------------------------------------------------

//----------------------------------------------------------------------------
//                     Private GLOBAL Variables (static)
//----------------------------------------------------------------------------

//----------------------------------------------------------------------------
//                     Functions (statics one are private)
//----------------------------------------------------------------------------

//----------------------------------------------------------------------------
// Start a transfert
//----------------------------------------------------------------------------
static VOID I2CStart(VOID)
{
	I2CWriteCMD(1, 1);
	I2CWriteCMD(0, 1);
	I2CWriteCMD(0, 0);
}

//----------------------------------------------------------------------------
// Stop a transfert
//----------------------------------------------------------------------------
static VOID I2CStop(VOID)
{
	I2CWriteCMD(0, 0);
	I2CWriteCMD(0, 1);
	I2CWriteCMD(1, 1);
}

//----------------------------------------------------------------------------
// Get the acknowledge from the receiver
//----------------------------------------------------------------------------
static BOOL I2CAcknowledge(VOID)
{
	I2CWriteCMD(1, 0);
	I2CWriteCMD(1, 1);
	I2CWriteCMD(1, 0);

	//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
	// Here we should check that the acknowledge signal has arrived, but HW has
	// not been implemented to do this, so we can not !
	//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
	return TRUE;
}

//----------------------------------------------------------------------------
// Send a byte on the bus (Most Significant Bit first)
//----------------------------------------------------------------------------
static VOID I2CSendByte(BYTE Data)
{
	BYTE i;

	for (i = 0; i < 8; i++) {
		if ((Data & 0x80) != 0) {
			I2CWriteCMD(1, 0);
			I2CWriteCMD(1, 1);
			I2CWriteCMD(1, 0);
		}
		else {
			I2CWriteCMD(0, 0);
			I2CWriteCMD(0, 1);
			I2CWriteCMD(0, 0);
		}
		Data = Data << 1;
	}
}

//----------------------------------------------------------------------------
// Function to send a byte to an I2C peripheral
//----------------------------------------------------------------------------
BOOL I2CSend(BYTE Address, BYTE SubAddress, BYTE Data)
{
	DebugAssert(Address != 0);

	I2CStart();

	I2CSendByte(Address);
	if (!I2CAcknowledge())
		return FALSE;

	I2CSendByte(SubAddress);
	if (!I2CAcknowledge())
		return FALSE;

	I2CSendByte(Data);
	if (!I2CAcknowledge())
		return FALSE;

	I2CStop();

	return TRUE;
}

//------------------------------- End of File --------------------------------