Why does LPC4337 freeze?

[alexander_gumen]

#LPC4337 hangs after repeated short-term drops

After a reset, the processor stops reading the PMC_PD0_SLEEP0_MODE register. In the test program for the OM13070 evaluation board hovering is determined by the red color of the LED after reset. To restore normal operation after a failure, you must simultaneously turn off VREG and VBAT - resetting or turn off only VREG will not unlock. 
It seems like PMC_PD0_SLEEP0_MODE clocking is lost.
Below is the text of the program - the whole program is Reset_Handler

void Reset_Handler(void)
{
    CREG_CREG0 = (1 << 0)   // Enable 1 kHz output
               | (1 << 1)   // Enable 32 kHz output
               | (0 << 2)   // Clear 32 kHz oscillator reset
               | (0 << 3)   // Powered 32 kHz oscillator
               | (1 << 5)   // Disable USB0 PHY
               | (3 << 6    // Disable RTC_ALARM pin according to errata
               | (2 << 8)   // level 2 (typ: assertion - 2.95 V, de-assertion - 3.03 V)
               | (3 << 10)  // level 3 (typ: assertion - 2.2 V, de-assertion - 2.28 V)
               | (3 << 12);  // Disable SAMPLE pin according to errata
    on_red_led();
    uint32_t dummy = PMC_PD0_SLEEP0_MODE;
    off_red_led();           
    on_green_led();
    while (1);
}
After adding a delay, there are no freezes

void Reset_Handler(void)
{
    CREG_CREG0 = (1 << 0)   // Enable 1 kHz output
               | (1 << 1)   // Enable 32 kHz output
               | (0 << 2)   // Clear 32 kHz oscillator reset
               | (0 << 3)   // Powered 32 kHz oscillator
               | (1 << 5)   // Disable USB0 PHY
               | (3 << 6    // Disable RTC_ALARM pin according to errata
               | (2 << 8)   // level 2 (typ: assertion - 2.95 V, de-assertion - 3.03 V)
               | (3 << 10)  // level 3 (typ: assertion - 2.2 V, de-assertion - 2.28 V)
               | (3 << 12);  // Disable SAMPLE pin according to errata
    on_red_led();
    for (uint32_t i = 1000000; i; i--)
        ;
    uint32_t dummy = PMC_PD0_SLEEP0_MODE;
    off_red_led();           
    on_green_led();
    while (1);
}

[Alexis_A]

Hello Alex,

Did you replace the ResetISR code for this one or are you calling this code after the reset intialization?

Best Regards,

Alexis Andalon

[alexander_gumen]

Hello Alexis,

I replaced the ResetISR code with this.

Test project in attachment

Best Regards,

Alex Humeniuk

[Alexis_A]

Hello Alex,

In the LPCOpen example (link here) before enabling the clocks there's some sentences need it for the correct functionality, for example, the RGU->RESET_CTRL0/1 are the first registers that are written, and this enables/disables if some reset peripherals, the clearing of the pending interrupts or the allocation of the VTOR.

There's also a function (Board_SetupClocking) where the CREG0 is called, maybe you could try the configuration you need to this one.

Let me know if this helps you.

Best Regards,

Alexis Andalon

[alexander_gumen]

Hello Alexis,
My device uses Deep Sleep mode. Therefore, according to Reset.3 Errata Sheet, 
I check the value in PD0_SLEEP0_MODE before initializing the peripherals. 
Since Errata Sheet does not indicate which configuration must be performed 
before checking PD0_SLEEP0_MODE, I only completed the installation of CREG0.

Best Regards,

Alex Humeniuk

[Alexis_A]

Hello Alex,

Do you have some problem using the ResetHandler found in the LPCOpen? 

Best Regards,

Alexis Andalon

[alexander_gumen]

Hello Alexis,

My test differs from the example in LPCOpen by the lack of a clocking setting. Why can't I use the default clocking settings when checking the Reset.3 problem.

Best Regards,

Alex Humeniuk