Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Menon — Thu, 08 May 2025 06:09:40 GMT

Hello,

Apologies for the delayed response. I was on vacation and have just returned to work.

Glad to hear you got it working in SPI mode!

[quote user="Ivenhor"]My current hypothesis is that the issue may be related to how the QSPI peripheral maps its IO lines across Port 0 and Port 1. In our current hardware design, the flash lines are distributed across both ports.[/quote]

As long as the pin configuration is valid and matches the hardware setup, assigning the I/O lines across both ports shouldn’t be an issue. I recommend probing the QSPI lines with a logic analyzer or oscilloscope to check the signals.

Kind regards,
Abhijith

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Ivenhor — Fri, 02 May 2025 14:23:38 GMT

We came back to this problem. We managed to connect an external flash in SPI mode.
My current hypothesis is that the issue may be related to how the QSPI peripheral maps its IO lines across Port 0 and Port 1. In our current hardware design, the flash lines are distributed across both ports.
Could this be the cause of the problem?

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Menon — Mon, 31 Mar 2025 13:17:50 GMT

Hello,

Good to hear that you checked the QSPI signals. If you would like a hardware review of your custom board, I recommend opening a new (private) ticket where you can share the hardware files.

Kind regards,
Abhijith

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Ivenhor — Mon, 31 Mar 2025 10:06:48 GMT

Checked the qspi signals on the devkit. Everything works.

However, on the custom board for some reason only CS works. Looks like the problem is somewhere in the hardware. Thanks for your help.

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Menon — Mon, 24 Mar 2025 15:10:12 GMT

Hello,

From the screenshot shared, I can see that the NFC pins have been configured correctly as GPIOs. So, if you are still seeing the error message shared in the first response, then this might not be an issue of conflicting NFC pins. I doubt if this could be a hardware issue. I recommend using a logic analyzer to see if signals are present on the QSPI lines.

Kind Regards,
Abhijith

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Ivenhor — Fri, 21 Mar 2025 09:09:40 GMT

I have prepared a project based on the spi flash example. In which I created an overlay with pinout of our board and added

&uicr {
    nfct-pins-as-gpios;
};

The problem is reproduced with this example. Before flashing, I executed nrfjprog --eraseall
The state of the registers in the debugger:

Example project

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Menon — Thu, 20 Mar 2025 10:07:52 GMT

Hello,

Are you getting the same error as before? Please make sure your hardware connections are correct and properly. If the issue is due to an NFC pin conflict, it should be resolved by the provided solution.

[quote user="Ivenhor"]Debugger shows that the NRF_UICR->NFCPINS register is at 0x00[/quote]

Are you seeing this after performing an eraseall?

Kind Regards,

Abhijith

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Ivenhor — Mon, 17 Mar 2025 12:29:43 GMT

Unfortunately that didn't help. I performed a complete wipe and flashed with the specified configuration for device three

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Menon — Wed, 12 Mar 2025 19:21:47 GMT

Hello,

The CONFIG_NFCT_PINS_AS_GPIOS=y is deprecated; see here. You only need to update the DTS to configure the NFC pins. Can you try running nrfjprog --eraseall, then rebuild and flash the application?

Kind Regards,

Abhijith

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Ivenhor — Wed, 12 Mar 2025 10:22:32 GMT

We are using SDK 2.5.2 and toolchain 2.8.0
Tried adding CONFIG_NFCT_PINS_AS_GPIOS=y to prj.conf and tried adding to devicetree:

&uicr {
    nfct-pins-as-gpios;
};

Unfortunately this did not help. Debugger shows that the NRF_UICR->NFCPINS register is at 0x00

Any other ideas?

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Menon — Wed, 12 Mar 2025 08:05:12 GMT

Hello,

[quote user=""]I suspect that the issue may be related to the fact that some of the assigned pins were originally used for NFC functionality.[/quote]

Yes, this is true. On the nRF52840, the default NFC pins are P0.09 (NFC1) and P0.10 (NFC2). See the product specification, pages 927 and 928, for pin assignments. These pins overlap with your QSPI IO3 (P0.09) and IO2 (P0.10). If NFC is enabled, it will conflict with QSPI. Which SDK version are you using?

To configure NFC pins as GPIOs, try including:

&uicr{

nfct-pins-as-gpios;
};

inside the device tree.

Kind REgards,

Abhijith

RE: Issue with QSPI Flash MX25R64 on Custom Pin Configuration (nRF52840)

Anthony Yuan — Wed, 12 Mar 2025 07:42:57 GMT

Could you try CONFIG_NFCT_PINS_AS_GPIOS=y