How to activate HSE monitoring

Applicable for STM32MP13x lines

1 Article purpose[edit]

The purpose of this article is to explain how to monitor the HSE oscillator.

If the HSE oscillator is used in the clock tree, it is possible to enable a monitoring function to detect and avoid over frequency. The LPTIM mechanism can detect any over frequency and triggers a tamper event which runs the appropriate custom actions.

2 How to activate the monitoring[edit]

By default, the HSE monitor is disabled in the dtsi "SoC" files.

To activate the HSE monitor, add this node in your board OP-TEE device tree

	&hse_monitor {
		status = "okay";