AT49F8192T

The AT49F8192 is a 5-volt-only, 8 megabit Flash Memory organized as 512K words of 16 bits each. Manufactured with Atmel's advanced nonvolatile CMOS technology, AT49F8192T offers access times to 90 ns with power dissipation of just 275 mW. When deselected, the CMOS standby current is less than 300 A.

AT49F8192T contains a user-enabled "boot block" protection feature. Two versions of the feature are available: the AT49F8192 locates the boot block at lowest order addresses ("bottom boot"); the AT49F8192T locates it at highest order addresses ("top boot").

To allow for simple in-system reprogrammability, the AT49F8192 does not require high input voltages for programming. Five-volt-only commands determine the read and programming operation of AT49F8192T. 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 AT49F8192 is performed by first erasing a block of data and then programming on a wordby- word basis.

AT49F8192T is erased by executing the erase command sequence; the device internally controls the erase operation. The memory is divided into three blocks for erase operations. There are two 8K word parameter block sections and one sector consisting of the boot block and the main memory array block. The AT49F8192 is programmed on a word-by-word basis. AT49F8192T has the capability to protect the data in the boot block; this feature of AT49F8192T is enabled by a command sequence. Once the boot block programming lockout feature is enabled, the data in the boot block cannot be changed when input levels of 5.5 volts or less are used. The typical number of program and erase cycles is in excess of 10,000 cycles.

The optional 8K word 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 of AT49F8192T is enabled, the boot sector is permanently protected from being reprogrammed.