The AT49F040 is a 5-volt-only in-system Flash Memory. Its 4 megabits of memory is organized as 524,288 words by 8 bits. Manufactured with Atmel's advanced nonvolatile CMOS technology, the device offers access times to 70 ns with power dissipation of just 275 mW over the commercial temperature range. When the device is deselected, the CMOS standby current is less than 100 A. The device contains a user-enabled "boot block" protection feature. Two versions of the feature are available: the AT49F040 locates the boot block at lowest order addresses ("bottom boot"); the AT49F040T locates it at highest order addresses ("top boot").