The "semihost_hardfault" when activating LIN break detection on the K32L2B31 most certainly suggests a problem that extends beyond simply setting the 'LKDE' bit. Possible causes include faulty LPUART clock configuration, accessing the peripheral before proper activation, memory access violations caused by an invalid base address, wrongly configured LIN break interrupts without a handler, or problems with the debugger/semihosting configuration. Before enabling LIN break detection, debug the initialization code, validate the base address, step through code with a debugger, check interrupts, simplify your code, and reference the datasheet to guarantee proper peripheral configuration. pa turnpike ez pass login