Reset button doesn't work on some nRF52840 DK PCA10056 1.0.0 boards

[mtfurlan_t]

The reset button doesn't seem to work on two of my PCA10056 1.0.0 development kits, but works on two others, and works on some earlier versions.

I tested by running the peripheral/uart and peripheral/blinky examples with SDK 15.0.0 and SDK 15.2.0

nrfjprog -f NRF52 -r works fine.

What could I be doing wrong to make the reset button not work on two specific boards? I'm not modifying the examples to not define CONFIG_GPIO_AS_PINRESET or anything.

[AndreasF]

Hi.

Could you first measure if you have a signal on P0.18 when you click on RESET?

And then measure SB42 when you click on RESET?

You find SB42 close to DEBUG IN

- Andreas

[mtfurlan_t]

So on a board where the reset button does work, SB42 and P0.18 are around 3V unrelated to if I am pressing the reset button or not.

When the board is off, I can see connectivity between P0.18 and SB42, but not to any of the pads of the reset button.

I don't see a difference on boards that don't have a working reset button.

[mtfurlan_t]

I have it defined in CFLAGS and ASMFLAGS

CFLAGS += -DCONFIG_GPIO_AS_PINRESET

ASMFLAGS += -DCONFIG_GPIO_AS_PINRESET

[AndreasF]

Hi.

Could you try to hold down the RESET button, and switch the board off and on, and release the RESET button.

Is LED 5 blinking slowly? If it is then the RESET button is connected to the debugger as it should be.

- Andreas

[mtfurlan_t]

That works fine.

The two boards that are having this issue are

PCA10056 1.0.0 2018.17 683415786

PCA10056 1.0.0 2018.17 683742869

One of the boards that works is

PCA10056 1.0.0 2018.20 683557756

Also working are the boards I tried under version 1.0.0

[AndreasF]

Hi.

Could you try this command on both board that does not work:

nrfjprog --memrd 0x10001200 --w 32 --n 8

Please post the output, it should be:

0x10001200: 00000012 00000012                     |........| 

- Andreas

[mtfurlan_t]

0x10001200: 00000015 00000015

[AndreasF]

Hi.

You pin reset number is not 18 somehow, as it should be, but 21.

Can you open the project you have programmed the boards you have a problem with and search for:

NRF_UICR->PSELRESET[0] and NRF_UICR->PSELRESET[1]

They should be set to 18, not 21.

Like this:

    #if defined (CONFIG_GPIO_AS_PINRESET)
        if (((NRF_UICR->PSELRESET[0] & UICR_PSELRESET_CONNECT_Msk) != (UICR_PSELRESET_CONNECT_Connected << UICR_PSELRESET_CONNECT_Pos)) ||
            ((NRF_UICR->PSELRESET[1] & UICR_PSELRESET_CONNECT_Msk) != (UICR_PSELRESET_CONNECT_Connected << UICR_PSELRESET_CONNECT_Pos))){
            NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen << NVMC_CONFIG_WEN_Pos;
            while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
            NRF_UICR->PSELRESET[0] = 18;
            while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
            NRF_UICR->PSELRESET[1] = 18;
            while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
            NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren << NVMC_CONFIG_WEN_Pos;
            while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
            NVIC_SystemReset();
        }
    #endif

You can find them in the system_nrf52840.c file.

Hopefully this works.

- Andreas