10 Clock sources
The STM32U5A9J-DK Discovery kit is using external HSE (16 MHz crystal) and external LSE (32.768 kHz
crystal) as clock references.
Using the HSE (instead of HSI) is mandatory to manage the DSI interface for the LCD module and the USB
high‑speed interface.
Any other internal clock reference might be used, but the clock tree might be adapted, and some features might
be unavailable.
HSE external crystal might be replaced by an external clock reference thanks to a solder bridge (MCO clock
source coming from STLINK-V3E, but the clock tree might be adapted, and some features might be unavailable).
The LSE might be replaced by internal LSI use, but the clock tree might be adapted, and some features might be
unavailable.
UM2967
Clock sources
UM2967 - Rev 1
page 25/68