in stm32h7, access to battery backup ram inside stm chip sometimes doesnt work. on nucleo board. when clk turned on, battery ram stops working. thanks

[Ishel.18]

battery backup ram works after power on. stops working ( get hard fault ) upon access to variable in battery backup ram. battery backup ram works when developement system dissconnected. sporadicaly stops working when ijet or segger connected to nucleo. works ok on eval board. doesnt work on nucleo board.

[Jack Peacock_2]

Sounds like an initialization problem at startup. Make sure the clock is on and the backup domain enabled for write access. When you get the hard fault check the PWR, SYSCFG and RCC registers. Do you have backup power to the VBAT pin? Make sure it stays within spec when main power switches off and on.

Jack Peacock