CC3220MOD: CC3220 pwm with speech generation and Mono Class-AB Audio Amplifier. 1-2Hz noise problem

Hi; 

I use the following code to understand the problem.

Although PWM and timer frequencies are the same. I saw an oscilloscope phase shift.

When I try the same code in the old sdk, the freaks are the same and there is no phase shift.

I suspect that there is an error in driver codes. I recorded the oscilloscope signal on the camera.

If you want to look at the link in the attachment

void timerArrangePwmDuty(Timer_Handle myHandle1)
{
pwmFlag=1 ;
GPIO_toggle(Board_BAT_CTRL);
}

void pwmtest(void){
PWM_Handle pwm1 = NULL;
PWM_Params params1;
Timer_Handle timer0;
Timer_Params params;

PWM_init();
PWM_Params_init(&params1);
params1.idleLevel = PWM_IDLE_LOW;
params1.dutyUnits = PWM_DUTY_COUNTS;
params1.dutyValue = 1800 ;
params1.periodUnits = PWM_PERIOD_US;
params1.periodValue = 45;
pwm1 = PWM_open(Board_PWM0, &params1);
duty = 1800;
PWM_setDuty(pwm1,duty);
PWM_start(pwm1);

Timer_init();
Timer_Params_init(&params);
params.period = 45;
params.periodUnits = Timer_PERIOD_US;
params.timerMode = Timer_CONTINUOUS_CALLBACK;
params.timerCallback = timerArrangePwmDuty;
timer0 = Timer_open(Board_TIMER1, &params);
Timer_start(timer0) ;

while(1)
{
if(pwmFlag){
pwmFlag=0 ;
}
}
}

Taylan,

Can you attach the oscilloscope output image where you are seeing the phase shift? I don' think that would cause your noise issue. Do you have a spectrum analyzer to use so you can see the frequencies present in your signal? This way we can identify the 1-2 hz noise.

Also, are you using a Launchpad? If flash the device and don't use your PC to power the device, does the noise go away?

Regards,
VR