Rui_flash read and write functions

Issue: Software


Details: Hi I actually had a questions: Lets say I have a send_data variable whose value I first save/write in the flash memory, sleep, wakeup and then read the value of the send_data from the flash memory again; then how do I that exactly go about doing that and also is there a specific keyword that I need to write next to it that marks it as a flash variable or something.