CMD38 (ERASE) is the SD card command that physically erases a defined range of sectors. It works in combination with CMD32 (ERASE_WR_BLK_START) and CMD33 (ERASE_WR_BLK_END), which set the start and end addresses of the erase range. Once CMD38 is issued, the card’s controller erases those blocks internally, rather than just overwriting them with zeros.