// FILE:	I2CComms.C
// TITLE:	DSP28035 (60Mhz)I2C test
//          Temperature Sensor TMP100 connected to GPIO33 (SCL) and GPIO32(SDA)
//			LED GPIO34 as life indicator 100 ms toggle
//			12 bit mode of TMP100, 1/16 degree celcius resolution
//			use watch window for variable "temperature" (type int; qvalue:8)
//###########################################################################
#include "DSP2803x_Device.h"
// TMP100 commands
#define TMP100_SLAVE 			0x48	// slave address TMP100 (ADDR0=ADDR1=0)
#define POINTER_TEMPERATURE 	0	
#define POINTER_CONFIGURATION 	1
#define POINTER_T_LOW 			2
#define POINTER_T_HIGH 			3
// external function prototypes
extern void InitSysCtrl(void);
extern void InitPieCtrl(void);
extern void InitPieVectTable(void);
extern void DSP28x_usDelay(long LoopCnt);
// Prototype statements for functions found within this file.
void Gpio_select(void);
void I2CA_Init(void);

long WaitTime = 110; // (9.3uS) @ 60Mhz TMS320F28035
int temperature;	// temperature = 2' Komplement of temparature (-128 ... +127 Celsius)
						// is an I8Q8 - Value 

void main(void)
{	
	InitSysCtrl();		// Basic Core Init from DSP2833x_SysCtrl.c
	DINT;			// Disable all interrupts	
	Gpio_select();	// GPIO9, GPIO11, GPIO34 and GPIO49 as output
					// to 4 LEDs at Peripheral Explorer	
	//	Initialize I2C
	I2CA_Init();

	// Send START, set pointer to Configuration register and set resolution to 12 bit
	I2caRegs.I2CCNT = 2;	
	I2caRegs.I2CDXR = POINTER_CONFIGURATION;
	I2caRegs.I2CMDR.all = 0x6E20;
	/*	Bit15 = 0;	no NACK in receiver mode
		Bit14 = 1;  FREE on emulation halt
		Bit13 = 1;  STT  generate START 
		Bit12 = 0;	reserved
		Bit11 = 1;  STP  generate STOP
		Bit10 = 1;  MST  master mode
		Bit9  = 1;  TRX  master - transmitter mode
		Bit8  = 0;	XA   7 bit address mode
		Bit7  = 0;  RM   nonrepeat mode, I2CCNT determines # of bytes
		Bit6  = 0;  DLB  no loopback mode
		Bit5  = 1;  IRS  I2C module enabled
		Bit4  = 0;  STB  no start byte mode
		Bit3  = 0;  FDF  no free data format
		Bit2-0: 0;  BC   8 bit per data byte	*/
	while(I2caRegs.I2CSTR.bit.XRDY == 0);		// wait until first byte is out
	I2caRegs.I2CDXR = 0x60;						// TMP100 in 12 bit mode (R1=R0=1)
	while(I2caRegs.I2CSTR.bit.SCD == 0);			// wait for STOP condition
	I2caRegs.I2CSTR.bit.SCD = 1;

	while(1)
	{    
			DSP28x_usDelay(WaitTime); 	// Delay time between STOP and START condition

			//	Send START and set pointer to temperature - register
			I2caRegs.I2CCNT 	= 1;				// pointer to temperature register
			I2caRegs.I2CDXR		= POINTER_TEMPERATURE;
			// Send start as master transmitter
	 		I2caRegs.I2CMDR.all = 0x6620;
			/*	Bit15 = 0;	no NACK in receiver mode
				Bit14 = 1;  FREE on emulation halt
				Bit13 = 1;  STT  generate START 
				Bit12 = 0;	reserved
				Bit11 = 0;  STP  not generate STOP
				Bit10 = 1;  MST  master mode
				Bit9  = 1;  TRX  master - transmitter mode
				Bit8  = 0;	XA   7 bit address mode
				Bit7  = 0;  RM   nonrepeat mode, I2CCNT determines # of bytes
				Bit6  = 1;  DLB  no loopback mode
				Bit5  = 1;  IRS  I2C module enabled
				Bit4  = 0;  STB  no start byte mode
				Bit3  = 0;  FDF  no free data format
				Bit2-0: 0;  BC   8 bit per data byte	*/
			while(I2caRegs.I2CSTR.bit.ARDY == 0);			// wait for access ready condition

			I2caRegs.I2CCNT		= 2;	// read 2 byte temperature 
			I2caRegs.I2CMDR.all = 0x6C20;
			/*	Bit15 = 0;	no NACK in receiver mode
				Bit14 = 1;  FREE on emulation halt
				Bit13 = 1;  STT  generate START 
				Bit12 = 0;	reserved
				Bit11 = 1;  STP  generate STOP
				Bit10 = 1;  MST  master mode
				Bit9  = 0;  TRX  master - receiver mode
				Bit8  = 0;	XA   7 bit address mode
				Bit7  = 0;  RM   nonrepeat mode, I2CCNT determines # of bytes
				Bit6  = 0;  DLB  no loopback mode
				Bit5  = 1;  IRS  I2C module enabled
				Bit4  = 0;  STB  no start byte mode
				Bit3  = 0;  FDF  no free data format
				Bit2-0: 0;  BC   8 bit per data byte	*/

			while(I2caRegs.I2CSTR.bit.RRDY == 0);	// wait for 1st byte
			temperature = I2caRegs.I2CDRR << 8;			// read upper 8 Bit (integers)
			// RRDY is automatically cleared by read of I2CDRR 
			while(I2caRegs.I2CSTR.bit.RRDY == 0);	// wait for 2nd byte
			temperature += I2caRegs.I2CDRR;				// read lower 8 Bit (fractions)
	}
} 

void Gpio_select(void)
{
	EALLOW;
	GpioCtrlRegs.GPAMUX1.all = 0;			// GPIO15 ... GPIO0 = General Puropse I/O
	GpioCtrlRegs.GPAMUX2.all = 0;			// GPIO31 ... GPIO16 = General Purpose I/O
	
	GpioCtrlRegs.GPBMUX1.all = 0;			// GPIO47 ... GPIO32 = General Purpose I/O
	GpioCtrlRegs.GPBMUX1.bit.GPIO32 = 1;	// GPIO32 = I2C - SDA
	GpioCtrlRegs.GPBMUX1.bit.GPIO33 = 1;	// GPIO33 = I2C - SCL

	GpioCtrlRegs.GPBPUD.bit.GPIO32 = 0;    // Enable pull-up for GPIO32 (SDAA)
	GpioCtrlRegs.GPBPUD.bit.GPIO33 = 0;	   // Enable pull-up for GPIO33 (SCLA)
	EDIS;
}  

void I2CA_Init(void)
{	
	I2caRegs.I2CMDR.bit.IRS = 0;	// Reset the I2C module
	// I2C slave address register
	I2caRegs.I2CSAR = TMP100_SLAVE;	
	// I2C 50Khz setting with TMS320F28035 60Mhz
	I2caRegs.I2CPSC.all = 5;									    
	I2caRegs.I2CCLKL = 95;
	I2caRegs.I2CCLKH = 95;						
	I2caRegs.I2CMDR.bit.IRS = 1;	// Take I2C out of reset
}

//===========================================================================
// End of SourceCode.
//===========================================================================