For a return value, 0 is returned when sucessful and -1 when failed. As the entire area is deleted at one time, this function allows you to delete the entire area in high speed, rather than repeating the execution of osFlashSectorErase.
Timer wait is done inside of osFlashAllErase. Since timer management is done by VI manager, it is necessary to boot VI manager with osCreateViManager prior to the use of this function. It takes from several msec to several hundred msec to delete the entire area of data.