1# Copyright (c) 2021, Linaro ltd 2# SPDX-License-Identifier: Apache-2.0 3 4description: STM32 HSE Clock 5 6compatible: "st,stm32-hse-clock" 7 8include: [fixed-clock.yaml] 9 10properties: 11 hse-bypass: 12 type: boolean 13 description: | 14 HSE crystal oscillator bypass 15 Set to the property to by-pass the oscillator with an external clock. 16 17 css-enabled: 18 type: boolean 19 description: | 20 HSE clock security system enabled 21 Set the property to enable the clock security system (CSS) for the HSE clock. 22 23 If a failure is detected on the HSE clock, the HSE oscillator is automatically disabled, 24 a clock failure event is sent to timers, and a non-maskable interrupt is generated to 25 inform the software about the failure, allowing the MCU to perform rescue operations. 26 See the MCU reference manual for details. 27 28 The interaction of CSS and low-power modes is unclear from the documentation. 29 For at least some devices Zephyr will reconfigure the clocks on resuming from low-power 30 modes; this will include re-enabling CSS. However it is important that you verify 31 this for your own hardware. 32
