The erase-write command is a combination of the
erase and write command, but without clearing the page
buffer after the erase command: The erase-write operation first erases
the selected page, then it writes the content of the page buffer to the same page.
When executed on the Flash, the CPU will be halted when the operations are ongoing. When executed on EEPROM, the CPU can continue executing code.
The page buffer will be automatically cleared after the operation is finished.