Worked on improving deep sleep functionality for si91x-based devices in the zephyrproject-rtos/hal_silabs repository, focusing on embedded systems and driver development using C. Addressed a bug by aligning deep sleep register access with CMSIS-6 standards, updating register mappings from NVIC->IP to NVIC->IPR and SCB->SHP to SCB->SHPR. This ensured correct saving and restoring of interrupt and system handler priorities during deep sleep, enhancing power management reliability. The work also involved updating CMSIS-6 defines across both si91x and WiseConnect platforms, resulting in improved maintainability and consistency for the Zephyr hardware abstraction layer within an RTOS environment.