CCS/TMS320F28379D: DAC A OUTPUT UPDATE

Hi Christian,

What does DACVALS say in the watch window?

Frank, 

Follow below the results in each windows:

The first two tables are the initial values and the second two are the update. I clicked on pause and changed the value of the potentiometer, and pressed play again. As you can see DACVALS doesn't update.

Christian,

I don't think your ADC_ISR is running. Can you place a global variable in the ADC_ISR and increment it? The variable should count up in the watch window. This way, you can be sure the ADC_ISR is running.

Hi Frank, 

I didn't really understand what you asked to do. Please find below the code:

/////TESTE ADC-TO -DAC

float v_fonte = 0.0;
float v_recomp = 0.0;
//
#define REFERENCE_VDAC 0
#define REFERENCE_VREF 1
#define DACA 1
#define DACB 2
#define DACC 3
#define REFERENCE REFERENCE_VREF
#define DAC_NUM DACA

//
// Globals
//
volatile struct DAC_REGS* DAC_PTR[4] = {0x0,&DacaRegs,&DacbRegs,&DaccRegs};
Uint16 low_limit = 410;
Uint16 high_limit = 3686;
void configureDAC(Uint16 dac_num);

////// teste fim

// Function Prototypes
//
void ConfigureADC(void);
void ConfigureEPWM(void);
void SetupADCEpwm(Uint16 channel);
interrupt void adca1_isr(void);

//
// Defines
//
#define RESULTS_BUFFER_SIZE 256

// Globals
//
Uint16 AdcaResults[RESULTS_BUFFER_SIZE];
Uint16 resultsIndex;
volatile Uint16 bufferFull;
Uint16 AdcaResult0;

void main(void)
{
//
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the F2837xD_SysCtrl.c file.
//
InitSysCtrl();

/////input xbar
EALLOW;
InputXbarRegs.INPUT5SELECT = 1;
EDIS;
///////input xbar

// Step 2. Initialize GPIO:
// This example function is found in the F2837xD_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
//
InitGpio(); // Skipped for this example

/////////OUTPUT X-BAR TEST ///////
EALLOW;
OutputXbarRegs.OUTPUT1MUX0TO15CFG.bit.MUX1 = 1;
OutputXbarRegs.OUTPUT1MUXENABLE.bit.MUX1 = 1;
OutputXbarRegs.OUTPUTLATCHENABLE.bit.OUTPUT1 = 0;
OutputXbarRegs.OUTPUTINV.bit.OUTPUT1 = 0;
EDIS;
////////OUTPUT X-BAR FIM //////

//
// 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 F2837xD_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 F2837xD_DefaultIsr.c.
// This function is found in F2837xD_PieVect.c.
//
InitPieVectTable();

EINT; // Enable Global interrupt INTM
ERTM; // Enable Global realtime interrupt DBGM
//
// Map ISR functions
//
EALLOW;
PieVectTable.ADCA1_INT = &adca1_isr; //function for ADCA interrupt 1
EDIS;

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

//
// Configure the ePWM
//
ConfigureEPWM();

//
// Setup the ADC for ePWM triggered conversions on channel 0
//
SetupADCEpwm(0);

// Configure DAC
//
configureDAC(DAC_NUM);
//
// 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

//
// Initialize results buffer
//
for(resultsIndex = 0; resultsIndex < RESULTS_BUFFER_SIZE; resultsIndex++)
{
AdcaResults[resultsIndex] = 0;
}
resultsIndex = 0;
bufferFull = 0;

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

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

//
//take conversions indefinitely in loop
//
do
{
//
//start ePWM
//
EPwm1Regs.ETSEL.bit.SOCAEN = 1; //enable SOCA
EPwm1Regs.TBCTL.bit.CTRMODE = 0; //unfreeze, and enter up count mode

//
//wait while ePWM causes ADC conversions, which then cause interrupts,
//which fill the results buffer, eventually setting the bufferFull
//flag
//
while(!bufferFull);
bufferFull = 0; //clear the buffer full flag

//
//stop ePWM
//
EPwm1Regs.ETSEL.bit.SOCAEN = 0; //disable SOCA
EPwm1Regs.TBCTL.bit.CTRMODE = 3; //freeze counter

//
//at this point, AdcaResults[] contains a sequence of conversions
//from the selected channel
//

//
//software breakpoint, hit run again to get updated conversions
//
asm(" ESTOP0");
}

while (1);

}

//
// ConfigureADC - 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;
}

//
// ConfigureEPWM - Configure EPWM SOC and compare values
//
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;
}

//
// SetupADCEpwm - Setup ADC EPWM acquisition window
//
void SetupADCEpwm(Uint16 channel)
{
Uint16 acqps;

//
//determine minimum acquisition window (in SYSCLKS) based on resolution
//
if(ADC_RESOLUTION_12BIT == AdcaRegs.ADCCTL2.bit.RESOLUTION)
{
acqps = 14; //75ns
}
else //resolution is 16-bit
{
acqps = 63; //320ns
}

//
//Select the channels to convert and end of conversion flag
//
EALLOW;
AdcaRegs.ADCSOC0CTL.bit.CHSEL = 2; //SOC0 will convert pin A0
AdcaRegs.ADCSOC0CTL.bit.ACQPS = acqps; //sample window is 100 SYSCLK cycles
AdcaRegs.ADCSOC0CTL.bit.TRIGSEL = 5; //trigger on ePWM1 SOCA/C
AdcaRegs.ADCSOC1CTL.bit.CHSEL = 2; //SOC0 will convert pin A0
AdcaRegs.ADCSOC1CTL.bit.ACQPS = acqps; //sample window is 100 SYSCLK cycles
AdcaRegs.ADCSOC1CTL.bit.TRIGSEL = 5; //trigger on ePWM1 SOCA/C
AdcaRegs.ADCSOC2CTL.bit.CHSEL = 2; //SOC0 will convert pin A0
AdcaRegs.ADCSOC2CTL.bit.ACQPS = acqps; //sample window is 100 SYSCLK cycles
AdcaRegs.ADCSOC2CTL.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
EDIS;
}

//
// adca1_isr - Read ADC Buffer in ISR
//
interrupt void adca1_isr(void)
{

v_fonte = AdcaResultRegs.ADCRESULT0;
v_recomp = v_fonte + 10;

DAC_PTR[DAC_NUM]->DACVALS.all = v_recomp ;

}

void configureDAC(Uint16 dac_num)
{
EALLOW;
DAC_PTR[dac_num]->DACCTL.bit.DACREFSEL = REFERENCE;
DAC_PTR[dac_num]->DACOUTEN.bit.DACOUTEN = 1;
//
DAC_PTR[dac_num]->DACCTL.bit.SYNCSEL = 1;
DAC_PTR[dac_num]->DACCTL.bit.LOADMODE = 0;
//
DAC_PTR[dac_num]->DACVALS.all = 0;
DELAY_US(10); // Delay for buffered DAC to power up
EDIS;
}
//
// End of file
//

Christian,

I meant increment a temp variable in your ADC ISR. Example below:

interrupt void adca1_isr(void)
{

temp_variable++;

If temp_variable keeps increasing in the watch window, that will confirm your ADC ISR is being called.

Hi Frank,

I guess the ADC_ISR is not being called. As I added the global variable as follow:

Uint16 temp_var = 0;

in ADC_ISR,

temp_var++;

Unfortunately in watch window, temp_var stays at 1. 

How can I make sure to ADC_ISR be called ?

Glad to hear the issue is resolved! Let us know if you ran into anymore issues.