What is programming margin in flash
There is a minimum time/voltage required to program a cell in FLASH
technologies, maybe its referring to additional margin over the minimums ?
Where did you see the reference ?
This might be useful -
In layman terms, Programming margin tells you how strongly the flash block is written. This parameter can be used to calculate the retention characteristics of a flash block.
Here is a basic reference for how FLASH works at the cell level, margins......