Setting VDD to 3.0V

RE: Setting VDD to 3.0V

Juergen — Fri, 10 Dec 2021 07:04:00 GMT

One final question from my side:

How to run the solution I mentioned before (devzone.nordicsemi.com/.../113169).

I made the changes as described:

In flash_placement.xml:

<MemorySegment name="UICR" start="$(UICR_START)" size="$(UICR_SIZE)">
  <ProgramSection alignment="4" keep="Yes" load="Yes" name=".uicr_regout0" start="0x10001304" size="4"/>
</MemorySegment>

In uicr_config.h (included in main.c):

const uint32_t REGOUT0 __attribute__((section(".uicr_regout0"))) = 4;

But after build and starting the debugger, REGOUT0 is "0xFFFFFFFF"" and not "0x00000004".

What is the reason?

RE: Setting VDD to 3.0V

Juergen — Thu, 09 Dec 2021 16:11:28 GMT

Your question regarding the J-Link has brought me to a solution:

Yes, the J-Link is able to work in this Range, but has to be restartet. So if I do as described befor until the Debugger stops with the HW-Error and then I restart and reconnect the J-Link in SES the Debug-Mode runs fine with 3V.

With this solution I can go on with my project.

So I would say my idea about a perfect solution will not run. No matter when VDD is changed - the J-Link has to be switched to 3V. This would run only perfectly if the J-Link would have an automatic Level adjustment.

Thank you a lot for your help.

RE: Setting VDD to 3.0V

Juergen — Thu, 09 Dec 2021 15:24:53 GMT

1. Debugger Problem:

I included this snippet in my program, found in "boards.c":
/*
* Function for configuring UICR_REGOUT0 register
* to set GPIO output voltage to 3.0V.
*/
static void gpio_output_voltage_setup(void)
{
// Configure UICR_REGOUT0 register only if it is set to default value.
if ((NRF_UICR->REGOUT0 & UICR_REGOUT0_VOUT_Msk) ==
(UICR_REGOUT0_VOUT_DEFAULT << UICR_REGOUT0_VOUT_Pos))
{
NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen;
while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

NRF_UICR->REGOUT0 = (NRF_UICR->REGOUT0 & ~((uint32_t)UICR_REGOUT0_VOUT_Msk)) |
(UICR_REGOUT0_VOUT_3V0 << UICR_REGOUT0_VOUT_Pos);

NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren;
while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

// System reset is needed to update UICR registers.
NVIC_SystemReset();
}
}

If I exclude "NVIC_SystemReset();" everthing is running ok, but VDD is still 1,8V. With a RESET or with "NVIC_SystemReset();" the debugger stops with a HW error.

2. What do I want as a perfect solution:

This is also explained in this comment by Jakob:

devzone.nordicsemi.com/.../113169

But unfortunately I don't get it run. Esspacially I have not found this path "Code > Build > Memory Segments "

RE: Setting VDD to 3.0V

haakonsh — Thu, 09 Dec 2021 13:44:18 GMT

You might have to disconnect/reconect/power-cycle the debug probe after you've changed the I/O voltage (changed VDD from 1.8V to 3.0V).

[quote user="Juergen"]The HW fault occurs when I change 0x304 after build - I tried this as a workaround. But isn't it better to set 0x304 in the build-process? [/quote]

What exactly do you mean by setting the valtage in the build-process and after build?
Do you mean do say that you're setting the voltage by writing to UICR with the debugger vs the MCU's app?

RE: Setting VDD to 3.0V

Juergen — Thu, 09 Dec 2021 10:41:50 GMT

I use J-Link ultra + and I just checked the description: It works with 1,2 up to 5V.

The HW fault occurs when I change 0x304 after build - I tried this as a workaround. But isn't it better to set 0x304 in the build-process?

RE: Setting VDD to 3.0V

haakonsh — Thu, 09 Dec 2021 09:32:54 GMT

[quote user=""]It is posible to set REGOUT0 in UICR 0x304 to 0x04. After the necessary Reset, this works in RUN-Mode outside IDE. In Debugger-Mode the Debugger shows an HW-error and stops. [/quote]

Does your debugger support 3.0V I/O?