MSP430FR5994: PWM Output Fluctuating when using Printf or other functions

Tool/software:

Hi, 

I am getting fluctuations of the PWM Voltage when I try to use a print function or any other function. The voltage goes high or low randomly then continues with the set duty cycle after the function is complete. The same operation works easily in Energia IDE, However not working in CCS.

Ideally, I want it to stay constant at the set duty cycle without interference.

Here's my code:

#include <msp430.h>

#include <stdio.h>

void initClock()

{

    WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer

    PM5CTL0 &= ~LOCKLPM5; // Disable GPIO high-impedance mode

    // Configure DCO to 1 MHz

    CSCTL0_H = CSKEY >> 8; // Unlock CS registers

    CSCTL1 = DCOFSEL_0 | DCORSEL; // Set DCO to 1 MHz

    CSCTL2 = SELA__VLOCLK | SELS__DCOCLK | SELM__DCOCLK; // Set ACLK = VLO; SMCLK = DCO; MCLK = DCO

    CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1; // Set all dividers to 1

    CSCTL0_H = 0; // Lock CS registers

}

void initPWM()

{

    // Configure P1.0 as PWM output

    P1DIR |= BIT0; // Set P1.0 as output

    P1SEL0 |= BIT0; // Select Timer_A function for P1.0

    // Configure Timer_A

    TA0CCR0 = 1000 - 1; // PWM period

    TA0CCTL1 = OUTMOD_7; // CCR1 reset/set

    TA0CCR1 = 0; // CCR1 PWM duty cycle

    TA0CTL = TASSEL_2 + MC_1 + TACLR; // SMCLK, up mode, clear TAR

}

void setPWMDutyCycle(unsigned int dutyCycle)

{

    TA0CCR1 = dutyCycle; // Set PWM duty cycle

}

void main(void)

{   

    initClock();

    initPWM();

    setPWMDutyCycle(100);

    while(1)

    {

        printf("hello\n");

        __delay_cycles(1000000); // Adjust delay for fade speed

    }

}