I tested the example in STM32Cube_FW_H7_V1.7.0/Projects/NUCLEO-H745ZI-Q/Templates_LL. It works perfectly on my Nucleo board.However, when I want to test my STM32H755 with the same code. The CM7 main blocked at while((LL_RCC_D2CK_IsReady() != 0) && ...