How do you flash the modem firmware on the NRF9151

[Jonathon Ross]

I was doing development on the development kit and I noticed that when flashing the device there is application core and modem core firmware that is flashed

I'm trying to figure out how to flash a production device with both the application and modem core firmware however the quick start doesn't allow a JTAG to be used to flash this. I imagine I can use the programmer, but I'm not sure what addresses to flash and what file to flash.

I've downloaded the modem core firmware from https://www.nordicsemi.com/Products/nRF9151/Download?lang=en#infotabs

It's also not very obvious which one of these should be used to flash.

I don't imagine the modem core is programmed prior to shipping?

Would the Serial LTE Modem firmware still function without the modem core being updated and send any UART traffic? Currently it sends "Ready" over the UART when it starts up on my dev kit, but would it print any error information on a chip that doesn't have modem core firmware?

I've built my application with Zephyr and one of the samples, which was super easy to do, loving the tools. But it's not clear to me if that image contains both cores or if I need another step.

We're attempting a custom board bringup and hoping to get this sorted out but I'm having trouble finding documentation on the modem core here.

Thank you,
Jon

[SwRa]

Hi Jonathan,

I don't imagine the modem core is programmed prior to shipping?

nRF91 Series devices come with preprogrammed modem firmware, that must be updated in production to the modem firmware version the end product is certified with. The modem firmware is not included in your application build and must be updated separately.

Would the Serial LTE Modem firmware still function without the modem core being updated and send any UART traffic?

The Serial LTE Modem (SLM) application requires a working modem firmware. 

You need to flash both the application firmware (your Zephyr-based app or a sample like Serial LTE Modem) and the modem firmware (modem core). These are separate binaries. You can either use the programmer app or nrfutil to do this. Using programmer, once you have selected the nRf91 device, Click "Add file" and select the modem firmware .zip file (do not unzip it). Then click "Write" to flash the modem. Then you can write the application firmware(Zephyr-built image (e.g., merged.hex or app_update.bin)).

All the above has also been explained here: Updating the DK firmware using Programmer and Updating the modem.

Best Regards,

Swathy