GPIO is set high by default

Abhay2080 — Tue, 31 Mar 2026 16:47:25 GMT

Hi,

I have Buzzer En connected to GPIO2_IO10 when En is high buzzer play, when EN is low buzzer is OFF. When my code stuck in while(1) inside reset vector - (

//Cpu Test Code

if(Post_Pass != run_cpu_post())

{

while(1);

}

in startup file then buzzer keep on playing , why and how to resolve this issue since even my bootloader code not yet start to execute.

void ResetISR(void)

{

/* Disable interrupts*/

__asm volatile ("cpsid i");

__asm volatile ("MSR MSP, %0" : : "r" (&_vStackTop) : );

#if defined (__USE_CMSIS)

/* If __USE_CMSIS defined, then call CMSIS SystemInit code*/

SystemInit();

#else

// Disable Watchdog

volatile unsigned int *WDOG1_WCR = (unsigned int *) 0x400B8000;

*WDOG1_WCR = *WDOG1_WCR & ~(1 << 2);

volatile unsigned int *WDOG2_WCR = (unsigned int *) 0x400D0000;

*WDOG2_WCR = *WDOG2_WCR & ~(1 << 2);

// Write watchdog update key to unlock

*((volatile unsigned int *)0x400BC004) = 0xD928C520;

// Set timeout value

*((volatile unsigned int *)0x400BC008) = 0xFFFF;

// Now disable watchdog via control register

volatile unsigned int *RTWDOG_CS = (unsigned int *) 0x400BC000;

*RTWDOG_CS = (*RTWDOG_CS & ~(1 << 7)) | (1 << 5);

#endif // (__USE_CMSIS)

/* Enable UIB power rails early */

StatusType status = UIB_PowerEnable_Startup();

if (status != Success)

{

// ToDo - Need to discuss what to do here

}

//Cpu Test Code

if(Post_Pass != run_cpu_post())

{

while(1);

}

//Ram Test Code

if(Post_Pass != run_ram_post())

{

while(1);

}

/* Copy the data sections from flash to SRAM.*/

unsigned int LoadAddr, ExeAddr, SectionLen;

unsigned int *SectionTableAddr;

/* Load base address of Global Section Table*/

SectionTableAddr = &__data_section_table;

/* Copy the data sections from flash to SRAM.*/

while (SectionTableAddr < &__data_section_table_end) {

LoadAddr = *SectionTableAddr++;

ExeAddr = *SectionTableAddr++;

SectionLen = *SectionTableAddr++;

data_init(LoadAddr, ExeAddr, SectionLen);

}

/* At this point, SectionTableAddr = &__bss_section_table;

* Zero fill the bss segment*/

while (SectionTableAddr < &__bss_section_table_end) {

ExeAddr = *SectionTableAddr++;

SectionLen = *SectionTableAddr++;

bss_init(ExeAddr, SectionLen);

}

#if !defined (__USE_CMSIS)

// Assume that if __USE_CMSIS defined, then CMSIS SystemInit code

// will setup the VTOR register

// Check to see if we are running the code from a non-zero

// address (eg RAM, external flash), in which case we need

// to modify the VTOR register to tell the CPU that the

// vector table is located at a non-0x0 address.

unsigned int * pSCB_VTOR = (unsigned int *) 0xE000ED08;

if ((unsigned int *)g_pfnVectors!=(unsigned int *) 0x00000000) {

*pSCB_VTOR = (unsigned int)g_pfnVectors;

}

#endif // (__USE_CMSIS)

#if defined (__cplusplus)

// Call C++ library initialisation

__libc_init_array();

#endif

/* Reenable interrupts*/

__asm volatile ("cpsie i");

#if defined (__REDLIB__)

/* Call the Redlib library, which in turn calls main()*/

__main();

#else

main();

#endif

* main() shouldn't return, but if it does, we'll just enter an infinite loop

while (1) {

;

}

Re: GPIO is set high by default

mayliu1 — Wed, 01 Apr 2026 04:32:02 GMT

Hi @Abhay2080 ,

Thank you so much for your interest in our products and for using our community.

1： Could you please confirm which specific i.MX RT device you are using in your application?
When the device is confirmed, we recommend checking the corresponding reference manual for the reset default state and mux configuration of GPIO2_IO10.

2：If the buzzer must remain OFF during startup, you may consider forcing it to the OFF state as early as possible in ResetISR() .

3: I suggest adding a hardware pull‑down resistor on the buzzer enable pin.

Best Regards

May Liu

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