AT49LV001T

The AT49BV/AT49LV001T is a 3-volt-only in-system reprogrammable Flash Memory. Its 1 megabit of memory is organized as 131,072 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 90 mW over the commercial temperature range. When the device is deselected, the CMOS standby current is less than 50 µA. For the AT49BV/LV001NT pin 1 for the DIP and PLCC packages and pin 9 for the TSOP package are don't connect pins.

To allow for simple in-system reprogrammability, the AT49BV/AT49LV001T does not require high input voltages for programming. Three-volt-only commands determine the read and programming operation of the device. 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 AT49BV/AT49LV001T is performed by erasing a block of data and then programming on a byte by byte basis. The byte programming time is a fast 50 µs. The end of a program cycle can be optionally detected by the DATA polling feature. Once the end of a byte program cycle has been detected, a new access for a read or program can begin. The typical number of program and erase cycles is in excess of 10,000 cycles.

The device AT49LV001T is erased by executing the erase command sequence; the device internally controls the erase operations. There are two 8K byte parameter block sections and two main memory blocks.

The device AT49LV001T has the capability to protect the data in the boot block; this feature is enabled by a command sequence. The 16K byte boot block section includes a reprogramming lock out feature to provide data integrity. The boot sector is designed to contain user secure code, and when the feature is enabled, the boot sector is protected from being reprogrammed.

In the AT49BV/AT49LV001T once the boot block programming lockout feature is enabled, the contents of the boot block are permanent and cannot be changed. In the AT49BV/LV001(T), once the boot block programming lockout feature is enabled, the contents of the boot block cannot be changed with input voltage levels of 5.5 volts or less.