SPI master reconfigure on nRF54L15

[Anthony Yuan]

Hi,

I have an application with 2 SPI IC connected to the same SPIM port of nRF54L15.

These 2 ICs have different SPI mode:

A: SPI Mode 1 (CPOL 0 CPHA 1)

B: SPI Mode 0 (CPOL 0 CPHA 0)

Should I reconfigure SPI before each communication? Like this post suggested (devzone.nordicsemi.com/.../spi-master-reconfigure)

And how should I modify drivers on ncs 3.2.3 to do that?

Regards,

Yuan Bo 

[Vidar Berg]

Hi Yuan,

The SPI mode is configured for each device on the bus individually. Do you have anything implemented already? If so, could you say a bit more about your current implementation. For example, if you are using the Zephyr SPI driver api directly from your application.

Best regards,

Vidar

[Anthony Yuan]

Hi Vidar,

My plan is using devicetree to define compatible spim devices like this (Not verified, may have some error):

&spi21 {
    compatible = "nordic,nrf-spim";
    status = "okay";
    
    pinctrl-0 = <&spi21_default>;
    pinctrl-1 = <&spi21_sleep>;
    pinctrl-names = "default", "sleep";

    nucleo_nfc@0 {
        compatible = "x-nucleo-nfc";
        reg = <0>;
        spi-max-frequency = <DT_FREQ_M(8)>;
        irq-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
        cs-gpios = <&gpio2 8 GPIO_ACTIVE_LOW>;
    };

    gd25q32e: gd25q32e@0 {
        compatible = "nordic,spi-nor";
        reg = <0>;
        writeoc = "pp4o";
        readoc = "read4io";
        sck-frequency = <8000000>;
        label = "GD25Q32E";
        jedec-id = [c8 40 16];
        size = <33554432>;
        has-dpd;
        t-enter-dpd = <10000>;
        t-exit-dpd = <35000>;
        cs-gpios = <&gpio2 9 GPIO_ACTIVE_LOW>;
    };
};

Regards,

Yuan Bo

[Vidar Berg]

Hi Yuan,

Thanks. So when the driver uses the SPI_DT_SPEC_INST_GET() or SPI_DT_SPEC_GET() macro to get the SPI configuration for a particular bus device, it will may also change the default SPI mode as shown here: https://github.com/nrfconnect/sdk-nrf/blob/7e6ec2ee7d41f6c2ff65ef3620ec07a2b04237f5/tests/benchmarks/multicore/idle_spim/src/main.c#L21 

Best regards,

Vidar

[Anthony Yuan]

Thanks for your reply.

Is it mean that I just need to define spi-cpha; in the spi mode 1's node and the spim driver will handle that?

[Vidar Berg]

Yes, you may add the spi-cpha; property to your devictree node. Alternatively, you can specify the mode to use in SW in your driver implementation.