//
//      Lab7A : TMS320F2812  Teaching CD ROM
//      (C) Frank Bormann
//
//###########################################################################
//
// FILE:	Lab7A.c
//
// TITLE:	DSP28 SPI - DAC TLV5617A, 2 sawtooth voltages 
//			CPU Timer0 ISR every 50 ms  
//			ADCINA1 and ADCINB1 to measure the DAC voltages
//			Watchdog active , served in ISR and main-loop 
//
//###########################################################################




#include "DSP281x_Device.h"

// Prototype statements for functions found within this file.

void Gpio_select(void);
void InitSystem(void);    
void SPI_Init(void);
void DAC_Update(char channel,int value);
interrupt void cpu_timer0_isr(void); // Prototype for Timer 0 Interrupt Service Routine
interrupt void ADC_ISR(void);

void main(void)
{
	int Voltage_A = 0;
	int Voltage_B = 511;       
	
	InitSystem();		// Initialize the DSP's core Registers
	
	Gpio_select();		// Setup the GPIO Multiplex Registers
	
	InitPieCtrl();		// Function Call to init PIE-unit ( code : DSP281x_PieCtrl.c)
	
	InitPieVectTable(); // Function call to init PIE vector table ( code : DSP281x_PieVect.c )
	
	// re-map PIE - entry for Timer 0 Interrupt 
	EALLOW;  // This is needed to write to EALLOW protected registers
   	PieVectTable.TINT0 = &cpu_timer0_isr;
   	EDIS;    // This is needed to disable write to EALLOW protected registers
	
	InitCpuTimers();
	
	// Configure CPU-Timer 0 to interrupt every 50 ms:
	// 150MHz CPU Freq, 50000 祍econds interrupt period
    ConfigCpuTimer(&CpuTimer0, 150, 50000);
    
    // Enable TINT0 in the PIE: Group 1 interrupt 7
   	PieCtrlRegs.PIEIER1.bit.INTx7 = 1;

	// Enable CPU INT1 which is connected to CPU-Timer 0:
    IER = 1;
    
	// Enable global Interrupts and higher priority real-time debug events:
   	EINT;   // Enable Global interrupt INTM
   	ERTM;   // Enable Global realtime interrupt DBGM
   	
   	CpuTimer0Regs.TCR.bit.TSS = 0;
   	
   	SPI_Init();    
   	InitAdc();
	// Configure ADC
   	AdcRegs.ADCTRL1.bit.SEQ_CASC = 0;	   // Dual Sequencer Mode
   	AdcRegs.ADCTRL1.bit.CONT_RUN = 0;	   // No Continuous run
   	AdcRegs.ADCTRL1.bit.CPS = 0;		   // prescaler = 1	
   	AdcRegs.ADCMAXCONV.all = 0x0001;       // Setup 2 conv's on SEQ1  
    AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x1; // Setup ADCINA0 as 1st SEQ1 conv.
    AdcRegs.ADCCHSELSEQ1.bit.CONV01 = 0x9; // Setup ADCINB0 as 2nd SEQ1 conv.
    AdcRegs.ADCTRL2.bit.EVA_SOC_SEQ1 = 0;  // Disable EVASOC to start SEQ1
	AdcRegs.ADCTRL2.bit.INT_ENA_SEQ1 = 1;  // Enable SEQ1 interrupt (every EOS)
	AdcRegs.ADCTRL3.bit.ADCCLKPS = 2;	   // Divide HSPCLK by 4
	
	EALLOW;	// This is needed to write to EALLOW protected registers
	PieVectTable.ADCINT = &ADC_ISR;
	EDIS;       // This is needed to disable write to EALLOW protected registers
	
	PieCtrlRegs.PIEIER1.bit.INTx6 = 1;	// Enable ADCINT in PIE group 1

	while(1)
	{    
  	    while(CpuTimer0.InterruptCount < 3); // wait for Timer 0
  		AdcRegs.ADCTRL2.bit.SOC_SEQ1 = 1;  // start ADC
  		CpuTimer0.InterruptCount = 0;      
  		GpioDataRegs.GPBTOGGLE.bit.GPIOB0 = 1;	// Toggle LED B0
  		DAC_Update('B',Voltage_B);
   		DAC_Update('A',Voltage_A);
  		if (Voltage_A++ > 511) Voltage_A = 0;
  		if (Voltage_B-- < 0) Voltage_B = 511;
    	EALLOW;
    	SysCtrlRegs.WDKEY = 0xAA;		// and serve watchdog #2		
	    EDIS;
	}
} 	

void Gpio_select(void)
{
	EALLOW;
	GpioMuxRegs.GPAMUX.all = 0x0;	// all GPIO port Pin's to I/O
    GpioMuxRegs.GPBMUX.all = 0x0;   
    GpioMuxRegs.GPDMUX.all = 0x0; 
    
    GpioMuxRegs.GPFMUX.all = 0xF;		 
    GpioMuxRegs.GPEMUX.all = 0x0; 
    GpioMuxRegs.GPGMUX.all = 0x0;			
										
    GpioMuxRegs.GPADIR.all = 0x0;	// GPIO PORT  as input
    GpioMuxRegs.GPBDIR.all = 0x00FF;	// GPIO Port B15-B8 input , B7-B0 output
    GpioMuxRegs.GPDDIR.all = 0x0;	// GPIO PORT  as input
    GpioMuxRegs.GPDDIR.bit.GPIOD0 = 1;  // /CS for DAC
    GpioMuxRegs.GPDDIR.bit.GPIOD6 = 1;	// /CS for EEPROM	
    GpioMuxRegs.GPEDIR.all = 0x0;	// GPIO PORT  as input
    GpioMuxRegs.GPFDIR.all = 0x0;	// GPIO PORT  as input
    GpioMuxRegs.GPGDIR.all = 0x0;	// GPIO PORT  as input

	GpioDataRegs.GPBDAT.all = 0x0000;	// Switch off LED's ( B7...B0) 
	GpioDataRegs.GPDDAT.bit.GPIOD0 = 1;	// deactivate /CS for the DAC 
	GpioDataRegs.GPDDAT.bit.GPIOD5 = 1; // deactivate /CS for the EEPROM
	
    GpioMuxRegs.GPAQUAL.all = 0x0;	// Set GPIO input qualifier values to zero
    GpioMuxRegs.GPBQUAL.all = 0x0;
    GpioMuxRegs.GPDQUAL.all = 0x0;
    GpioMuxRegs.GPEQUAL.all = 0x0;
    EDIS;
}     


void InitSystem(void)
{
   	EALLOW;
   	SysCtrlRegs.WDCR= 0x00AF;		// Setup the watchdog 
   									// 0x00E8  to disable the Watchdog , Prescaler = 1
   									// 0x00AF  to NOT disable the Watchdog, Prescaler = 64
   	SysCtrlRegs.SCSR = 0; 			// Watchdog generates a RESET	
   	SysCtrlRegs.PLLCR.bit.DIV = 10;	// Setup the Clock PLL to multiply by 5
    
   	SysCtrlRegs.HISPCP.all = 0x1; // Setup Highspeed Clock Prescaler to divide by 2
   	SysCtrlRegs.LOSPCP.all = 0x2; // Setup Lowspeed CLock Prescaler to divide by 4
      	
   	// Peripheral clock enables set for the selected peripherals.   
   	SysCtrlRegs.PCLKCR.bit.EVAENCLK=0;
   	SysCtrlRegs.PCLKCR.bit.EVBENCLK=0;
   	SysCtrlRegs.PCLKCR.bit.SCIAENCLK=0;
   	SysCtrlRegs.PCLKCR.bit.SCIBENCLK=0;
   	SysCtrlRegs.PCLKCR.bit.MCBSPENCLK=0;
   	SysCtrlRegs.PCLKCR.bit.SPIENCLK=1;
   	SysCtrlRegs.PCLKCR.bit.ECANENCLK=0;
   	SysCtrlRegs.PCLKCR.bit.ADCENCLK=1;
   	EDIS;
}

interrupt void cpu_timer0_isr(void)
{
    CpuTimer0.InterruptCount++;  
   	// Serve the watchdog every Timer 0 interrupt
   	EALLOW;
	SysCtrlRegs.WDKEY = 0x55;		// Serve watchdog #1
	EDIS;

   // Acknowledge this interrupt to receive more interrupts from group 1
   PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
} 

void SPI_Init(void)
{
	SpiaRegs.SPICCR.all = 0x004F;	
	// Bit 7 , Reset = 0 : 
	// Bit 6 , Clock Polarity = 1 : data output on falling edge of CLK
	//       , together with CLOCK PHASE = 1 : data output is one half cycle before
	//       , falling edge pf SPICLK
	// Bit 5 , reserved
	// Bit 4 , SPILBK = 0 : no loopback mode
	// Bit 3-0 , Chars = 1111 : 16 bit data transfer
	SpiaRegs.SPICTL.all =0x000E;
	// Bit 7-5 : reserved
	// Bit 4 , Overrun INT Enable = 0 : Disable Receiver Overrun Interrupt
	// Bit 3 , Clock-Phase = 1 , one half clock delay
	// Bit 2 , Master/Slave = 1 ,  MASTER
	// Bit 1 , Talk = 1 ,  Enable Transmission
	// Bit 0 , SPI INT ENA = 0 , No SPI - Interrupts
	SpiaRegs.SPIBRR = 124;
	// SPI Baud Rate =  LSPCLK / ( SPIBRR + 1)
	//				 =  37,5 MHz / ( 124 + 1 )
	//			     =  300 kHz
	SpiaRegs.SPICCR.bit.SPISWRESET = 1; // relinquish SPI from reset
}  

void DAC_Update(char channel, int value)
{
	int i;
	GpioDataRegs.GPDDAT.bit.GPIOD0 = 0;	// activate /CS for the DAC 
	if (channel == 'B') 
		SpiaRegs.SPITXBUF =  0x1000 + (value<<2);// transmit data to DAC-Buffer
	if (channel == 'A')
	    SpiaRegs.SPITXBUF =  0x8000 + (value<<2);// transmit data to DAC-A 
								                // and update DAC-B with Buffer
	while (SpiaRegs.SPISTS.bit.INT_FLAG == 0) ; // wait for end of transmission
	for (i=0;i<100;i++);            // wait for DAC to finish off
	GpioDataRegs.GPDDAT.bit.GPIOD0 = 1;	// deactivate /CS for the DAC 
	i = SpiaRegs.SPIRXBUF;			// dummy read of RXBUF to reset SPI 
    
}
//===========================================================================
// End of SourceCode.
//===========================================================================