Alliance Memory M25Px Serial Flash Embedded Memory Devices feature advanced write protection mechanisms accessed by a high-speed SPI-compatible bus. These memory devices can be programmed 1byte to 256bytes at a time using the PAGE PROGRAM command. The M25P10A memory device is organized as 4-sectors with each containing 128 pages and the M25P80 memory device is organized as 16-sectors with each containing 256 pages. The M25PE40 memory device is organized as 8-sectors that is divided into 16 sub-sectors each containing 256 pages in each sector and each sub-sector contains 16 pages. The entire memory of the M25P10A and M25P80 devices can be erased using the BULK ERASE command, or it can be erased one sector at a time using the SECTOR ERASE command. The memory of M25PE40 can be erased one page at a time using the PAGE ERASE command. The SECTOR ERASE command can be used for erasing one sector at a time and SUBSECTOR ERASE command for one sub-sector at a time. The M25PE40 memory can also be erased using the BULK ERASE command.