Help me about a delay in MCU startup

Yes, debugging hardware is unlikely to transition a power down of the target.

You could check DBGMCU setting with respect to debugging and powering.

Perhaps you can ask more senior staff or professor/supervisor for assistance?

Really have no idea here what code you're running, or why it would power down after several seconds. If active/dynamic analysis isn't helping, perhaps you can do some more through static analysis of the code, and the startup process.

If you leave main() or exit()/abort(), expect the system to collapse into failure.

Yes, debugging hardware is unlikely to transition a power down of the target.

You could check DBGMCU setting with respect to debugging and powering.

Perhaps you can ask more senior staff or professor/supervisor for assistance?

Really have no idea here what code you're running, or why it would power down after several seconds. If active/dynamic analysis isn't helping, perhaps you can do some more through static analysis of the code, and the startup process.

If you leave main() or exit()/abort(), expect the system to collapse into failure.

-> after power on, the LED starts flashing rapidly for few seconds (between 2 to 10 seconds) then LED becomes steadily on.

I encountered similar problem before.

The LCD of our device shares the same pins with a FT240X USB Chip, our device has a Lithium battery and a USB charging circuit. I encountered similar problem as you, so I discuss this problem with my hardware colleague, he did a full hardware analysis, and told me that this hardware needs a few seconds to become stable after power on. Since hardware can't be modified, he asked me to do a Sleep_Mode_IO_Config() immediately after power on, then wait for a while, then start to do the Runtime_IO_Config() and the real work. After this software modification, the problem doesn't disappear, but under our control.

Sleep_Mode_IO_Config(): He checked and decided each GPIO pins should be configured as In or Out, if it is an output pin, it should be high or low.

int main(void)
{
    int i;
    static uint8_t Wait_PC_Connect = 1;

    LPC_SYSCON->PDRUNCFG |= (1u<<3);    /* Set BOD Power-Down bit */
    GPIO_OutInit();
    Enable_Timer32B0();

    Sleep_Mode_IO_Config();
    delay_in_ms(50);
    GPIOSetValue( LPC_GPIO0, 7, 1 );    // En_OP_Power - ON
    Blink_Delay(8);
    Runtime_IO_Config();

    ADC_Init();
    SSP_Init();
    I2C_Init( LPC_I2C, 400000 );
    UART_Init(115200);

    delay_in_ms(10);
    LCD_Init();
    delay_in_ms(10);
    GPIOSetValue( LPC_GPIO2, 10, 1 );    // LCD_BKL - ON

-> after power on, the LED starts flashing rapidly for few seconds (between 2 to 10 seconds) then LED becomes steadily on.

After this software modification, the
few seconds (between 2 to 10 seconds)
becomes a fixed number, let's say at most 5 seconds.

Dear John
Thanks for your advise.
I found that my problem is from the firmware since I tried with earlier versions of the firmware and modified it to new version. Now this problem has disappeared. I am trying to find out what are the differences that has made this problem.

Hamed Adldoost
Posted 29-Jun-2015 16:30 GMT
I used the same program to run on STM32L152RC discovery board but I had no problem.

So, it was not the same program?