TMS320F28075 internal temperature

//###########################################################################
// FILE:   adc_soc_epwm_tempsensor_cpu01.c
// TITLE:  Sample temperature sensor and convert to temperature for F2807x.
//
//! \addtogroup cpu01_example_list
//! <h1> ADC temperature sensor conversion (adc_soc_epwm_tempsensor)</h1>
//!
//! This example sets up the ePWM to periodically trigger the ADC.  The
//! ADC converts the internal connection to the temperature sensor,
//! which is then interpreted as a temperature by calling the
//! GetTemperatureC function.
//!
//! After the program runs, the memory will contain:\n
//! - \b sensorSample \b: The raw reading from the temperature sensor. \n
//! - \b sensorTemp \b: The interpretation of the sensor sample as a
//! temperature in degrees Celsius.
//!
//###########################################################################
// $TI Release: F2807x Support Library vXXX $
// $Release Date: XXX CDT 2015 $
// $Copyright: Copyright (C) 2013-2015 Texas Instruments Incorporated -
//             http://www.ti.com/ ALL RIGHTS RESERVED $
//###########################################################################

#include "F28x_Project.h"     // Device Headerfile and Examples Include File

void ConfigureADC(void);
void ConfigureEPWM(void);
void SetupADCEpwm(void);
interrupt void adca1_isr(void);

Uint16 sensorSample;
int16 sensorTemp;

void main(void)
{
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the F2807x_SysCtrl.c file.
    InitSysCtrl();

// Step 2. Initialize GPIO:
// This example function is found in the F2807x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
    InitGpio(); // Skipped for this example
    
// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
    DINT;

// Initialize the PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the F2807x_PieCtrl.c file.
    InitPieCtrl();

// Disable CPU interrupts and clear all CPU interrupt flags:
    IER = 0x0000;
    IFR = 0x0000;

// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example.  This is useful for debug purposes.
// The shell ISR routines are found in F2807x_DefaultIsr.c.
// This function is found in F2807x_PieVect.c.
    InitPieVectTable();

//Map ISR functions
    EALLOW;
    PieVectTable.ADCA1_INT = &adca1_isr; //function for ADCA interrupt 1
    EDIS;

//Configure the ADC and power it up
    ConfigureADC();

//Initialize the temperature sensor
//Note: The argument needs to change if using a VREFHI voltage other than 3.0V
    InitTempSensor(3.0);

//Configure the ePWM
    ConfigureEPWM();

//Setup the ADC for ePWM triggered conversions on temperature sensor
    SetupADCEpwm();

//Enable global Interrupts and higher priority real-time debug events:
    IER |= M_INT1; //Enable group 1 interrupts
    EINT;  // Enable Global interrupt INTM
    ERTM;  // Enable Global realtime interrupt DBGM

//enable PIE interrupt
    PieCtrlRegs.PIEIER1.bit.INTx1 = 1;

//sync ePWM
    EALLOW;
    CpuSysRegs.PCLKCR0.bit.TBCLKSYNC = 1;

//start ePWM
    EPwm1Regs.ETSEL.bit.SOCAEN = 1;  //enable SOCA
    EPwm1Regs.TBCTL.bit.CTRMODE = 0; //unfreeze, and enter up count mode

//take conversions indefinitely in loop
        while(1);
}

//Write ADC configurations and power up the ADC for both ADC A and ADC B
void ConfigureADC(void)
{
	EALLOW;

	//write configurations
	AdcaRegs.ADCCTL2.bit.PRESCALE = 6; //set ADCCLK divider to /4
    AdcSetMode(ADC_ADCA, ADC_RESOLUTION_12BIT, ADC_SIGNALMODE_SINGLE);

	//Set pulse positions to late
	AdcaRegs.ADCCTL1.bit.INTPULSEPOS = 1;

	//power up the ADC
	AdcaRegs.ADCCTL1.bit.ADCPWDNZ = 1;

	//delay for 1ms to allow ADC time to power up
	DELAY_US(1000);

	EDIS;
}

void ConfigureEPWM(void)
{
	EALLOW;
	// Assumes ePWM clock is already enabled
	EPwm1Regs.ETSEL.bit.SOCAEN	= 0;	        // Disable SOC on A group
	EPwm1Regs.ETSEL.bit.SOCASEL	= 4;	        // Select SOC on up-count
	EPwm1Regs.ETPS.bit.SOCAPRD = 1;		        // Generate pulse on 1st event
	EPwm1Regs.CMPA.bit.CMPA = 0x0800;          // Set compare A value to 2048 counts
	EPwm1Regs.TBPRD = 0x1000;			        // Set period to 4096 counts
	EPwm1Regs.TBCTL.bit.CTRMODE = 3;            // freeze counter
	EDIS;
}

void SetupADCEpwm(void)
{
	Uint16 acqps;

	acqps = 83; //temperature sensor needs at least 700ns acquisition time

	//Select the channels to convert and end of conversion flag
	EALLOW;
	AdcaRegs.ADCSOC0CTL.bit.CHSEL = 13;  //SOC0 will convert internal connection A13
	AdcaRegs.ADCSOC0CTL.bit.ACQPS = acqps; //sample window is 100 SYSCLK cycles
	AdcaRegs.ADCSOC0CTL.bit.TRIGSEL = 5; //trigger on ePWM1 SOCA/C
	AdcaRegs.ADCINTSEL1N2.bit.INT1SEL = 0; //end of SOC0 will set INT1 flag
	AdcaRegs.ADCINTSEL1N2.bit.INT1E = 1;   //enable INT1 flag
	AdcaRegs.ADCINTFLGCLR.bit.ADCINT1 = 1; //make sure INT1 flag is cleared
}

interrupt void adca1_isr(void)
{
	sensorSample = AdcaResultRegs.ADCRESULT0;
	sensorTemp = GetTemperatureC(sensorSample);

	AdcaRegs.ADCINTFLGCLR.bit.ADCINT1 = 1; //clear INT1 flag
	PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
}

//###########################################################################
// FILE:   F2807x_TempSensorConv.c
// TITLE:  F2807x Temperature Sensor Conversion Functions
//###########################################################################
// $TI Release: F2807x Support Library vXXX $
// $Release Date: XXX $
// $Copyright: Copyright (C) 2013-2015 Texas Instruments Incorporated -
//             http://www.ti.com/ ALL RIGHTS RESERVED $
//###########################################################################

#include "F2807x_device.h"     // F2807x Headerfile Include File
#include "F2807x_Examples.h"   // F2807x Examples Include File

// Useful definitions
#define FP_SCALE 32768       //Scale factor for Q15 fixed point numbers (2^15)
#define FP_ROUND FP_SCALE/2  //Added to Q15 numbers before converting to integer to round the number

// Amount to add to Q15 fixed point numbers to shift from Celsius to Kelvin
// (Converting guarantees number is positive, which makes rounding more efficient)
#define KELVIN 273
#define KELVIN_OFF FP_SCALE*KELVIN


// The following pointers to function calls are:
//Slope of temperature sensor (deg. C / ADC code).  Stored in fixed point Q15 format.
#define getTempSlope() (*(int (*)(void))0x7036E)()
//ADC code corresponding to temperature sensor output at 0 deg. C
#define getTempOffset() (*(int (*)(void))0x70372)()

int32 tempSensor_tempSlope;
Uint16 tempSensor_tempOffset;
float32 tempSensor_scaleFactor;

//Initialize the temperature sensor by powering up the sensor, loading
//the calibration values from OTP to RAM, and recording the intended
//VREFHI voltage.  
//note: This function doesn't support VREFLO != 0.0V, but this could 
//be implemented if desired. 
void InitTempSensor(float32 vrefhi_voltage)
{
	EALLOW;

	//power up the the temperature sensor
	AnalogSubsysRegs.TSNSCTL.bit.ENABLE = 1;
	//delay to allow the sensor to power up
	DELAY_US(1000);

    EDIS;

    //need to remember VREFHI voltage so that sensor readings can be scaled
    //to match 2.5V values used for calibration data.
    tempSensor_scaleFactor = vrefhi_voltage;
    
    //check the device revision
    if(DevCfgRegs.REVID >= 3)
    {
        //for production devices (Rev. C), pull the slope and offset from OTP
        tempSensor_tempSlope = (int32)getTempSlope();
        tempSensor_tempOffset = getTempOffset();
    }
    else
    {
        //for pre-production devices, use these static values for slope and offset
        tempSensor_tempSlope = 5196;
        tempSensor_tempOffset = 1788;
    }   
}

//This function uses the reference data stored in OTP to convert the raw temperature
//sensor reading into degrees C
int16 GetTemperatureC(int16 sensorSample)
{
    sensorSample = (int16)((tempSensor_scaleFactor/2.5)*(sensorSample));

    return ((sensorSample - tempSensor_tempOffset)*tempSensor_tempSlope + FP_ROUND + KELVIN_OFF)/FP_SCALE - KELVIN;
}

//This function uses the reference data stored in OTP to convert the raw temperature
//sensor reading into degrees K
int16 GetTemperatureK(int16 sensorSample)
{
    sensorSample = (int16)((2.5/tempSensor_scaleFactor)*(sensorSample));

    return ((sensorSample - tempSensor_tempOffset)*tempSensor_tempSlope + FP_ROUND + KELVIN_OFF)/FP_SCALE;
}