at49lh00b4 ATMEL Corporation, at49lh00b4 Datasheet - Page 2

• Manufacturer Part Number: at49lh00b4
• Description: 4-megabit Top Boot, Bottom Partitioned Firmware Hub And Low-pin Count Flash Memory
• Manufacturer: ATMEL Corporation

The memory array of the AT49LH00B4 can be sectored in two ways simply by using two differ-
ent erase commands. Using one erase command allows the device to contain a total of eleven
sectors comprised of a 64-Kbyte boot sector, six 64-Kbyte sectors, a 32-Kbyte sector, a
16-Kbyte sector, and two 8-Kbyte sectors. The 64-Kbyte boot sector is located at the top (upper-
most) of the device’s memory address space and can be hardware write protected by using the
TBL pin. Alternatively, by using a different erase command, the memory array can be arranged
into eight even erase sectors of 64-Kbyte each.
The AT49LH00B4 supports two hardware interfaces: The FWH/LPC interface for In-System
operations and the A/A Mux interface for programming during manufacturing. The Interface Con-
figuration (IC) pin of the device provides the control between these two interfaces. An internal
Command User Interface (CUI) serves as the control center between the device interfaces and
the internal operation of the nonvolatile memory. A valid command sequence written to the CUI
initiates device automation.
Specifically designed for use in 3-volt systems, the AT49LH00B4 supports read, program, and
erase operations with a supply voltage range of 3.0V to 3.6V. No separate voltage is required for
programming and erasing.
The AT49LH00B4 utilizes fixed program and erase times, independent of the number of pro-
gram and erase cycles that have occurred. Therefore, the system does not need to be calibrated
or correlated to the cumulative number of program and erase cycles.
AT49LH00B4
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3379C–FLASH–3/05