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

[Ivenhor]

Hello,

I am experiencing an issue while trying to connect an external flash memory (MX25R64) via the QSPI interface on an nRF52840-based custom board. My pin configuration differs from the one used in the official development kit.

Here is my pin setup:

qspi_default: qspi_default {
    group1 {
        psels = <NRF_PSEL(QSPI_SCK, 1, 12)>,
                <NRF_PSEL(QSPI_IO0, 1, 11)>,
                <NRF_PSEL(QSPI_IO1, 1, 10)>,
                <NRF_PSEL(QSPI_IO2, 0, 10)>,
                <NRF_PSEL(QSPI_IO3, 0, 9)>,
                <NRF_PSEL(QSPI_CSN, 0, 31)>;
        nordic,drive-mode = <NRF_DRIVE_H0H1>;
    };
};

qspi_sleep: qspi_sleep {
    group1 {
        psels = <NRF_PSEL(QSPI_SCK, 1, 12)>,
                <NRF_PSEL(QSPI_IO0, 1, 11)>,
                <NRF_PSEL(QSPI_IO1, 1, 10)>,
                <NRF_PSEL(QSPI_IO2, 0, 10)>,
                <NRF_PSEL(QSPI_IO3, 0, 9)>;
        low-power-enable;
    };
    group2 {
        psels = <NRF_PSEL(QSPI_CSN, 0, 31)>;
        low-power-enable;
        bias-pull-up;
    };
};

Flash configuration:

&qspi {
    status = "okay";
    pinctrl-0 = <&qspi_default>;
    pinctrl-1 = <&qspi_sleep>;
    pinctrl-names = "default", "sleep";

    mx25r64: mx25r6435f@0 {
        compatible = "nordic,qspi-nor";
        reg = <0>;
        writeoc = "pp4io";
        readoc = "read4io";
        sck-frequency = <2000000>;
        jedec-id = [ c2 28 17 ];
        sfdp-bfp = [ e5 20 f1 ff ff ff ff 03 44 eb 08 6b 08 3b 04 bb ee ff ff ff ff ff 00 ff ff ff 00 ff 0c 20 0f 52 10 d8 00 ff 23 72 f5 00 82 ed 04 cc 44 83 68 44 30 b0 30 b0 f7 c4 d5 5c 00 be 29 ff f0 d0 ff ff ];
        size = <67108864>;
        has-dpd;
        t-enter-dpd = <10000>;
        t-exit-dpd = <35000>;
    };
};

Upon initialization, I get the following error:

<err> qspi_nor: JEDEC id [00 00 00] expect [c2 28 17]

I suspect that the issue may be related to the fact that some of the assigned pins were originally used for NFC functionality. I attempted to reconfigure them as GPIO using:

nrfx_nvmc_word_write((uint32_t) & (NRF_UICR->NFCPINS),
                     (uint32_t)UICR_NFCPINS_PROTECT_Disabled);

However, this did not resolve the issue.

Could you please provide guidance on resolving this problem?

Thank you for your assistance!

[Menon]

Hello,

I suspect that the issue may be related to the fact that some of the assigned pins were originally used for NFC functionality.

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

[Ivenhor]

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?

[Menon]

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.

Ivenhor said:

Debugger shows that the NRF_UICR->NFCPINS register is at 0x00

Are you seeing this after performing an eraseall?

Kind Regards,

Abhijith