Why does the change in the Feature Row appear to take effect immediately when using a background mode operation?
The Feature Row programming will take effect immediately, whether it's Transparent Programming or Normal (offline) Programming. The idea behind it is that we want to make the content inside the shadow register always in sync with the actual flash memory content. The Flash Programming might not be successful on every single bit, especially after several thousand program/erase cycles, and the flash bits will degrade eventually. And those unsuccessful/failed bits, we want the flash contents immediately reflect those error information in Shadows Register. During verification, the readout is from the shadow register. Also, a lot of FR contents are related to security; we want them to take effect as soon as possible.
The customer's idea of trying to background programming the Feature Row will not be feasible due to the above explanation