The AT49BV/LV040 are 3-volt-only, 4-megabit Flash memories organized as 524,288 words of 8-bits each. Manufactured with Atmel's advanced nonvolatile CMOS technology, the devices offer access times to 120 ns with power dissipation of just 90 mW over the commercial temperature range. When the device is deselected, the CMOS standby current is less than 50 A. The device contains a user-enabled "boot block" protection feature. Two versions of the feature are available: the AT49BV/LV040 locates the boot block at lowest order addresses ("bottom boot"); the AT49BV/LV040T locates it at highest order addresses ("top boot").