Just wanted to put this here in case anyone else runs into it. The STM32L43xxx/44xxx/45xxx/46xxx microcontroller family has SRAM1 and SRAM2. Difference is SRAM2 has extra features like optional parity check. For this problem, I do not have parity check enabled. When SEGGER_RTT_SECTION is not set, the linker may place _SEGGER_RTT and other RTT stuff in SRAM2 since RAM space (.data + .bss) is contiguous starting at 0x2000 0000 and there is no distinction from the linker's perspective. When the RTT…