AT49BV4096AT

The AT49BV004(T) and AT49BV4096A(T) are 3-volt, 4-megabit Flash Memories organized as 524,288 words of 8 bits each or 256K words of 16 bits each. Manufac- tured with Atmel's advanced nonvolatile CMOS technology, the devices offer access times to 120 ns with power dissipation of just 67 mW at 2.7V read. When 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 AT49BV004/4096A locates the boot block at lowest order addresses ("bottom boot"); the AT49BV004T/4096AT locates it at highest order addresses ("top boot").

To allow for simple in-system reprogrammability, the AT49BV004(T)/4096A(T) does not require high input voltages for programming. Reading data out of the device is similar to reading from an EPROM; it has standard CE ,OE , and WE inputs to avoid bus contention. Reprogramming the AT49BV004(T)/4096A(T) is performed by first erasing a block of data and then programming on a byte-by-byte or word-by-word basis.