external memory SPI pin configuration in serial ltm application

[Amol_Chor]

Hello,

 

We are developing a custom board having nrf9160 cellular modem and we are using serial ltm application in it.

in serial ltm application there is pin selection available for UART2 in overlay file of nrf9160

same way can we configure the pin for external memory in serial ltm application?

 Thanks !!

[Håkon Alseth]

Hi,

 

Yes, you can add an entry for &spiX overlay, with new pinctrl definitions.

Here's an example:

arduino_spi: &spi3 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	cs-gpios = <&arduino_header 16 GPIO_ACTIVE_LOW>; /* D10 */
	pinctrl-0 = <&my_spi3_default>;
	pinctrl-1 = <&my_spi3_sleep>;
	pinctrl-names = "default", "sleep";
	cs-gpios = <&arduino_header 16 GPIO_ACTIVE_LOW>, /* D10 */
		   <&gpio0 25 GPIO_ACTIVE_LOW>;
	mx25r64: mx25r6435f@1 {
		compatible = "jedec,spi-nor";
		status = "okay";
		reg = <1>;
		spi-max-frequency = <8000000>;
		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 48 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>;
	};	
};

&pinctrl {
	my_spi3_default: my_spi3_default {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 13)>,
				<NRF_PSEL(SPIM_MISO, 0, 12)>,
				<NRF_PSEL(SPIM_MOSI, 0, 11)>;
			nordic,drive-mode = <NRF_DRIVE_H0H1>;
		};
	};

	my_spi3_sleep: my_spi3_sleep {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 13)>,
				<NRF_PSEL(SPIM_MISO, 0, 12)>,
				<NRF_PSEL(SPIM_MOSI, 0, 11)>;
			low-power-enable;
		};
	};
};

Please note that if you use external flash in mcuboot (for dual banking), you will also have to add specific overlay in your mcuboot configuration as well, similar as done in the asset tracker application:

https://github.com/nrfconnect/sdk-nrf/tree/v2.5.0/applications/asset_tracker_v2/child_image/mcuboot/boards

 

Kind regards,

Håkon

[Amol_Chor]

How can we test the connected external flash?
Is there any specific overlay file to use external flash memory?

[Håkon Alseth]

Once you have setup the overlay, you can for instance run a FOTA:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/applications/serial_lte_modem/doc/FOTA_AT_commands.html

 

Amol_Chor said:

Is there any specific overlay file to use external flash memory?

The former attached overlay sets up the mx25r64 - if you use another flash device, you will need to populate the jedec-id and subsequent parameters per your chosen device.

You can find some of these parameters by running this sample: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/samples/drivers/jesd216/README.html

However; please note that you will need an overlay present matching the board that you've chosen. Here's an example for the nRF52840DK: https://github.com/nrfconnect/sdk-zephyr/blob/v3.5.99-ncs1/samples/drivers/jesd216/boards/nrf52840dk_nrf52840_spi.overlay

 

Kind regards,

Håkon

[Amol_Chor]

Thanks for quick response !!

I do not want to modify the application firmware, only configure the project configuration files and overlay files.
Using this I want to achieve the enable the external flash and test using sample app. 

Håkon Alseth said:

Once you have setup the overlay, you can for instance run a FOTA:

(In my region lte-m/nbIoT network not available )  so I am not able to test FOTA commands.

Håkon Alseth said:

The former attached overlay sets up the mx25r64

I am using the same chip as external flash, please let me know the basic configuration on version nrf connect sdk 2.5.0, also sample application (how to validate external memory)

[Håkon Alseth]

Hi,

 

Add the overlay and flash; check the runtime output of the sample to see if it booted correctly.

You can also check the partition layout to verify that the mcuboot_secondary is located in the "flash_primary" or "external_flash" region.

 

to verify correct connections and overlay; please have a look at for instance jesd216 sample and run this on your board.

Kind regards,

Håkon