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TMS320F280049C: Assistance Needed with ADC_B Configuration on F280049C MCU

Part Number: TMS320F280049C

Tool/software:

I am currently working on configuring ADC_B (ADC Interrupt) on the F280049C MCU. However, I am encountering an issue where the ADC result is consistently 0. In contrast, when I configure ADC_A, it functions correctly.

Could you please assist me in resolving this issue with ADC_B? Below, I have included my code for your reference.

#include "F28x_Project.h"
#include "driverlib.h"
#include "device.h"

//
// Defines
//
#define RESULTS_BUFFER_SIZE 256

//
// Globals
//
uint16_t adcAResults[RESULTS_BUFFER_SIZE]; // Buffer for results
uint16_t index; // Index into result buffer
volatile uint16_t bufferFull; // Flag to indicate buffer is full

//
// Function Prototypes
//
void initADC(void);
void initEPWM(void);
void initADCSOC(void);
__interrupt void adcB1ISR(void);

//
// Main
//
void main(void)
{
//
// Initialize device clock and peripherals
//
InitSysCtrl();

//
// Initialize GPIO
//
InitGpio();

//
// 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.
//
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).
//
InitPieVectTable();

//
// Map ISR functions
//
EALLOW;
PieVectTable.ADCB1_INT = &adcB1ISR; // Corrected to ADCA1_INT for ADCA interrupt 1
EDIS;

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

//
// Configure the ePWM
//
initEPWM();

//
// Setup the ADC for ePWM triggered conversions on channel 1
//
initADCSOC();

//
// 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(index = 0; index < RESULTS_BUFFER_SIZE; index++)
{
adcAResults[index] = 0;
}

index = 0;
bufferFull = 0;

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

//
// Sync ePWM
//
EALLOW;
CpuSysRegs.PCLKCR0.bit.TBCLKSYNC = 1;
EDIS;

//
// Take conversions indefinitely in loop
//
while(1)
{
//
// 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

//
// Software breakpoint. At this point, conversion results are stored in
// adcAResults.
//
// Hit run again to get updated conversions.
//
ESTOP0;
}
}

//
// initADC - Function to configure and power up ADCA.
//
void initADC(void)
{
//
// Setup VREF as internal
//

EALLOW;

//
// Set ADCCLK divider to /4
//
AdcbRegs.ADCCTL2.bit.PRESCALE = 6;

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

//
// Power up the ADC and then delay for 1 ms
//
AdcbRegs.ADCCTL1.bit.ADCPWDNZ = 1;
EDIS;

DELAY_US(1000);
}

//
// initEPWM - Function to configure ePWM1 to generate the SOC.
//
void initEPWM(void)
{
EALLOW;

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;
}

//
// initADCSOC - Function to configure ADCA's SOC0 to be triggered by ePWM1.
//
void initADCSOC(void)
{
//
// Select the channels to convert and the end of conversion flag
//
EALLOW;

AdcbRegs.ADCSOC0CTL.bit.CHSEL = 5; // SOC0 will convert pin C5
AdcbRegs.ADCSOC0CTL.bit.ACQPS = 9; // Sample window is 10 SYSCLK cycles
AdcbRegs.ADCSOC0CTL.bit.TRIGSEL = 5; // Trigger on ePWM1 SOCC

AdcbRegs.ADCINTSEL1N2.bit.INT1SEL = 0; // End of SOC0 will set INT1 flag
AdcbRegs.ADCINTSEL1N2.bit.INT1E = 1; // Enable INT1 flag
AdcbRegs.ADCINTFLGCLR.bit.ADCINT1 = 1; // Make sure INT1 flag is cleared

EDIS;
}

//
// adcA1ISR - ADC A Interrupt 1 ISR
//
__interrupt void adcB1ISR(void)
{
//
// Add the latest result to the buffer
// ADCRESULT0 is the result register of SOC0
adcAResults[0] = AdcbResultRegs.ADCRESULT0;
index++;

//
// Set the bufferFull flag if the buffer is full
//
if(RESULTS_BUFFER_SIZE <= index)
{
index = 0;
bufferFull = 1;
}

//
// Clear the interrupt flag
//
AdcbRegs.ADCINTFLGCLR.bit.ADCINT1 = 1;

//
// Check if overflow has occurred
//
if(1 == AdcbRegs.ADCINTOVF.bit.ADCINT1)
{
AdcbRegs.ADCINTOVFCLR.bit.ADCINT1 = 1; //clear INT1 overflow flag
AdcbRegs.ADCINTFLGCLR.bit.ADCINT1 = 1; //clear INT1 flag
}

//
// Acknowledge the interrupt
//
PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
}

//
// End of File
//