For my Kinetis K21 project, after deepsleep wakeup(lls)( Before going to sleep erase/write flash is working without any problem ), any try to erase/write flash sector from software is giving hard fault. Even if we do software reset, still problem persists. While issuing the command for sector erase the controller is giving hard fault. But after a power on reset it is possible to erase/write the flash. Please help me to narrow down the issue and solve it.