Hello @liyouliu
Hope you are doing well.
By any chance, is this inquiry related to a demo application from the JN5189 SDK? If so, which one?
Could you please provide more details about your development? What do you mean by "storage unit"?
If you are interested in Flash driver usage for initialization, erase and programming, you could take a look at the flash_test demo application from the JN5189. More information on Flash driver can be found inside JN5189 SDK documentation folder > docs > wireless > MCUXpresso SDK API Reference Manual_JN5189 Chapter 13 FLASH: Flash driver.
In addition, I would recommend using Persistent Data Manager (PDM) instead to store non-volatile data. More information on PDM can be found inside JN5189 SDK documentation folder > docs > Common > Connectivity Framework Reference Manual, Section 3.6 PDM component and docs > wireless > Zigbee > JN-UG-3133 Core Utilities, Chapter 2 PDM and Chapter 6 PDM API.
Regards,
Eduardo.
