topic Re: SCTIMER Interupt Usage on FRDM-MCXN947 board in MCX Microcontrollers

SCTIMER Interupt Usage on FRDM-MCXN947 board

Kevin_Pang — Thu, 10 Jul 2025 13:46:38 GMT

Dear NXP community,

Currently, I am developing a program using the on board SCTIMER peripheral. I am trying to start the CTIMER0 peripheral in the third state of my state implementation with the SCTIMER to produce a PWM signal. This PWM signal is routed to a GPIO pin. To realize this, I will need to implement an interupt in my third state to start the CTIMER0 in that state specifically. However, I have some trouble with programming such interupt as i am not very experienced. Could you help me out?

The code I am currently working on is specified below:

void SCT0_IRQHandler(void)

{

SCTIMER_EventHandleIRQ(SCT0_PERIPHERAL);

// Start CTIMER only when SCTIMER reaches state 2

CTIMER_StartTimer(CTIMER0_PERIPHERAL);

PRINTF("CTIMER started from SCTIMER state 2 event.\r\n");

}

static void SCT0_init(void) {

CTIMER0_init();

SCTIMER_Init(SCT0_PERIPHERAL, &SCT0_initConfig);

/* Enable interrupt SCT0_IRQN request in the NVIC */

/* Initialization of state 0 */

SCTIMER_SetupPwm(SCT0_PERIPHERAL, &SCT0_pwmSignalsConfig[0], kSCTIMER_EdgeAlignedPwm, 100U, SCT0_CLOCK_FREQ, &SCT0_pwmEvent[0]);

SCTIMER_SetupPwm(SCT0_PERIPHERAL, &SCT0_pwmSignalsConfig[2], kSCTIMER_EdgeAlignedPwm, 100U, SCT0_CLOCK_FREQ, &SCT0_pwmEvent[2]);

SCTIMER_CreateAndScheduleEvent(SCT0_PERIPHERAL, kSCTIMER_OutputRiseEvent, 0, kSCTIMER_Out_0, kSCTIMER_Counter_U, &SCT0_event[0]);

SCTIMER_SetupNextStateAction(SCT0_PERIPHERAL, 1, SCT0_event[0]);

SCTIMER_IncreaseState(SCT0_PERIPHERAL);

/* Initialization of state 1 */

/* Schedule the period event for the PWM */

SCTIMER_ScheduleEvent(SCT0, SCT0_pwmEvent[0]);

/* Schedule the pulse event for the PWM */

SCTIMER_ScheduleEvent(SCT0, SCT0_pwmEvent[0] + 1);

SCTIMER_SetupPwm(SCT0_PERIPHERAL, &SCT0_pwmSignalsConfig[1], kSCTIMER_EdgeAlignedPwm, 100U, SCT0_CLOCK_FREQ, &SCT0_pwmEvent[1]);

SCTIMER_CreateAndScheduleEvent(SCT0_PERIPHERAL, kSCTIMER_OutputRiseEvent, 0, kSCTIMER_Out_0, kSCTIMER_Counter_U, &SCT0_event[1]);

SCTIMER_SetupNextStateAction(SCT0_PERIPHERAL, 2, SCT0_event[1]);

SCTIMER_IncreaseState(SCT0_PERIPHERAL);

/* Initialization of state 2 */

/* Schedule the period event for the PWM */

SCTIMER_ScheduleEvent(SCT0, SCT0_pwmEvent[0]);

/* Schedule the pulse event for the PWM */

SCTIMER_ScheduleEvent(SCT0, SCT0_pwmEvent[0] + 1);

SCTIMER_SetupPwm(SCT0_PERIPHERAL, &SCT0_pwmSignalsConfig[3], kSCTIMER_EdgeAlignedPwm, 100U, SCT0_CLOCK_FREQ, &SCT0_pwmEvent[3]);

SCTIMER_CreateAndScheduleEvent(SCT0_PERIPHERAL, kSCTIMER_OutputRiseEvent, 0, kSCTIMER_Out_0, kSCTIMER_Counter_U, &SCT0_event_startCTimer);

SCTIMER_SetCallback(SCT0_PERIPHERAL, SCT0_IRQHandler, SCT0_event_startCTimer);

EnableIRQ(SCT0_IRQn);

}

The picture below shows the wave form at the start. The goal is to start the blue PWM signal at the fourth rising edge of the yellow PWM signal.

Re: SCTIMER Interupt Usage on FRDM-MCXN947 board

Kevin_Pang — Mon, 14 Jul 2025 12:40:08 GMT

PROBLEM SOLVED:

I have already found out the solution to program the interupt correctly. The code implementation is shown below (CTIMER init not shown):

void SCT0_IRQHandler(void)

{

SCTIMER_EventHandleIRQ(SCT0_PERIPHERAL);

}

void Start_CTIMER(void)

{

// Start CTIMER only when SCTIMER reaches state 2

CTIMER_StartTimer(CTIMER0_PERIPHERAL);

PRINTF("CTIMER started from SCTIMER state 2 event.\r\n");

}

const sctimer_config_t SCT0_initConfig = {

.enableCounterUnify = true,

.clockMode = kSCTIMER_System_ClockMode,

.clockSelect = kSCTIMER_Clock_On_Rise_Input_0,

.enableBidirection_l = false,

.enableBidirection_h = false,

.prescale_l = 0U,

.prescale_h = 0U,

.outInitState = 0U,

.inputsync = 0U

};

const sctimer_pwm_signal_param_t SCT0_pwmSignalsConfig[4] = {

{

.output = kSCTIMER_Out_0,

.level = kSCTIMER_HighTrue,

.dutyCyclePercent = 50U

{

.output = kSCTIMER_Out_1,

.level = kSCTIMER_HighTrue,

.dutyCyclePercent = 100U

{

.output = kSCTIMER_Out_1,

.level = kSCTIMER_HighTrue,

.dutyCyclePercent = 0U

{

.output = kSCTIMER_Out_1,

.level = kSCTIMER_HighTrue,

.dutyCyclePercent = 0U

}

};

uint32_t SCT0_pwmEvent[4];

uint32_t SCT0_event[4];

uint32_t SCT0_event_startCTimer;

static void SCT0_init(void) {

SCTIMER_Init(SCT0_PERIPHERAL, &SCT0_initConfig);

/* Enable interrupt SCT0_IRQN request in the NVIC */

/* Initialization of state 0 */

SCTIMER_SetupPwm(SCT0_PERIPHERAL, &SCT0_pwmSignalsConfig[0], kSCTIMER_EdgeAlignedPwm, 100U, SCT0_CLOCK_FREQ, &SCT0_pwmEvent[0]);

SCTIMER_SetupPwm(SCT0_PERIPHERAL, &SCT0_pwmSignalsConfig[2], kSCTIMER_EdgeAlignedPwm, 100U, SCT0_CLOCK_FREQ, &SCT0_pwmEvent[2]);

SCTIMER_CreateAndScheduleEvent(SCT0_PERIPHERAL, kSCTIMER_OutputRiseEvent, 0, kSCTIMER_Out_0, kSCTIMER_Counter_U, &SCT0_event[0]);

SCTIMER_SetupNextStateAction(SCT0_PERIPHERAL, 1, SCT0_event[0]);

SCTIMER_IncreaseState(SCT0_PERIPHERAL);

/* Initialization of state 1 */

/* Schedule the period event for the PWM */

SCTIMER_ScheduleEvent(SCT0, SCT0_pwmEvent[0]);

/* Schedule the pulse event for the PWM */

SCTIMER_ScheduleEvent(SCT0, SCT0_pwmEvent[0] + 1);

SCTIMER_SetupPwm(SCT0_PERIPHERAL, &SCT0_pwmSignalsConfig[1], kSCTIMER_EdgeAlignedPwm, 100U, SCT0_CLOCK_FREQ, &SCT0_pwmEvent[1]);

SCTIMER_CreateAndScheduleEvent(SCT0_PERIPHERAL, kSCTIMER_OutputRiseEvent, 0, kSCTIMER_Out_0, kSCTIMER_Counter_U, &SCT0_event[1]);

SCTIMER_SetupNextStateAction(SCT0_PERIPHERAL, 2, SCT0_event[1]);

SCTIMER_IncreaseState(SCT0_PERIPHERAL);

/* Initialization of state 2 */

/* Schedule the period event for the PWM */

SCTIMER_ScheduleEvent(SCT0, SCT0_pwmEvent[0]);

/* Schedule the pulse event for the PWM */

SCTIMER_ScheduleEvent(SCT0, SCT0_pwmEvent[0] + 1);

SCTIMER_SetupPwm(SCT0_PERIPHERAL, &SCT0_pwmSignalsConfig[3], kSCTIMER_EdgeAlignedPwm, 100U, SCT0_CLOCK_FREQ, &SCT0_pwmEvent[3]);

SCTIMER_CreateAndScheduleEvent(SCT0_PERIPHERAL, kSCTIMER_OutputRiseEvent, 0, kSCTIMER_Out_0, kSCTIMER_Counter_U, &SCT0_event_startCTimer);

SCTIMER_SetCallback(SCT0_PERIPHERAL, Start_CTIMER, SCT0_event_startCTimer);

SCTIMER_EnableInterrupts(SCT0, (1U << SCT0_event_startCTimer));

EnableIRQ(SCT0_IRQn);

}

Re: SCTIMER Interupt Usage on FRDM-MCXN947 board

Habib_MS — Mon, 14 Jul 2025 18:47:43 GMT

Hello @Kevin_Pang,
I am glad your issue is solved. Please let me know if there is anything that I can do for you.
BR
Habib

Re: SCTIMER Interupt Usage on FRDM-MCXN947 board

Kevin_Pang — Thu, 17 Jul 2025 11:40:08 GMT

Dear Habib,

Thank you for reaching out.

I now have a problem with the development board. It consequently raises an exception "Unable to open probe index 1" with the error "Probe not open" when trying to debug my project. Afterwards, it fails to connect with the core. This happened suddenly without any change in my setup. Can you help me solve this issue?

Kind regards,
Kevin Pang

Re: SCTIMER Interupt Usage on FRDM-MCXN947 board

Habib_MS — Thu, 17 Jul 2025 16:25:24 GMT

Hello @Kevin_Pang,

Could you try running one of the SDK examples, such as "hello_world," to determine whether the exception is caused by your code or is specific to your board?
BR
Habib

Re: SCTIMER Interupt Usage on FRDM-MCXN947 board

Kevin_Pang — Fri, 18 Jul 2025 11:27:51 GMT

Dear Habib,

I have tried to run a basic sdk example and I still encounter the same error.

Kind regards,

Kevin

Re: SCTIMER Interupt Usage on FRDM-MCXN947 board

Habib_MS — Mon, 21 Jul 2025 16:50:58 GMT

Hello @Kevin_Pang,

It looks like the issue you are experiencing is discussed in the next thread. I recommend following the suggestions provided by ZhangJennie to see if they help resolve the problem.

BR
Habib