Startup time of NUCLEO G431RB varies greatly

[Tobe]

After troubleshooting this issue , i found, that i have a greatly varying startup time.

I have this minimal code:

int main(void)
{
	/* GPIO Ports Clock Enable */
	__HAL_RCC_GPIOC_CLK_ENABLE();

	GPIO_InitTypeDef my_GPIO_InitStruct = {0};

	// TEST PIN
	my_GPIO_InitStruct.Pin = GPIO_PIN_3;
	my_GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
	my_GPIO_InitStruct.Pull = GPIO_PULLUP;
	HAL_GPIO_Init(GPIOC, &my_GPIO_InitStruct);

	GPIOC->BSRR = (uint32_t) GPIO_PIN_3;
}

 I know that some clock setting needs some time, but this? it varies from 100ms to 1600ms !

Could it be, that the chip is bad?

[Andrew Neil]

You haven't shown what your clock setup is.

How are you measuring the startup time?

Does it make any difference if the startup is from a power cycle, or just a reset?

[Tobe]

I removed my clock setup to create a minimal code. See the picture for the measurement. I do reset with a wavegen.

I also measured with power cycle: With powercycle it was very constant (2.143s).

But now that i switched back, i can not reproduce this issue anymore. Maybe i got the setup not back as it was with the issue? Or maybe a powercycle removed the issue.

 

It is not constant at about 200us.