power consumption +400uA with TFM enabled

[embeddedCoder]

I'm using the peripheral_lbs sample for testing with the PPK2 kit and the 1.0.0 nRF54L15-DK. 

I have disabled logging and serial and added PM_DEVICE and PM_DEVICE_RUNTIME.

A build for nRF54l15 DK nRF54l15 Application gives me low power I am expecting.

A build for  nRF54l15 DK nRF54l15 Application Non Secure increases current by a constant 400uA. This is visible by a constant horizontal line between peaks.

How can I reduce TFM power/make it sleep?

Thanks

[Simonr]

Hi

TF-M support for the nRF54L15 is experimental, so there's no guarantee that it's power optimized at all: https://docs.nordicsemi.com/bundle/ncs-3.1.1/page/nrf/releases_and_maturity/software_maturity.html#trusted_firmware-m_support

That being said, 400µA matches the current consumption for the UART, and TF-M has logging enabled by default. It might just be a matter of disabling logging in TF-M.

Best regards,

Simon

[embeddedCoder]

I tried

CONFIG_TFM_LOG_LEVEL_SILENCE=y

CONFIG_TFM_SECURE_UART1=n

but that didn't seem to help unless I'm missing how to disable the UART?