M50FLW040A datasheet(7/64 Pages) STMICROELECTRONICS

7 / 64 page

M50FLW040A, M50FLW040B

Summary description

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Summary description

The M50FLW040 is a 4 Mbit (512 Kb x8) non-volatile memory that can be read, erased and

reprogrammed. These operations can be performed using a single low voltage (3.0 to 3.6V)

supply. For fast programming and fast erasing in production lines, an optional 12 V power

supply can be used to reduce the erasing and programming time.

The memory is divided into 8 Uniform Blocks of 64 KBytes each, three of which are divided

into 16 uniform sectors of 4 KBytes each (see Appendix A for details). All blocks and sectors

can be erased independently. So, it is possible to preserve valid data while old data is

erased. Blocks can be protected individually to prevent accidental program or erase

commands from modifying their contents.

Program and erase commands are written to the Command Interface of the memory. An on-

chip Program/Erase Controller simplifies the process of programming or erasing the

memory by taking care of all of the special operations that are required to update the

memory contents. The end of a program or erase operation can be detected and any error

conditions identified. The command set to control the memory is consistent with the JEDEC

standards.

Two different bus interfaces are supported by the memory:

●

The primary interface, the FWH/LPC Interface, uses Intel’s proprietary Firmware Hub

(FWH) and Low Pin Count (LPC) protocol. This has been designed to remove the need

for the ISA bus in current PC Chipsets. The M50FLW040 acts as the PC BIOS on the

Low Pin Count bus for these PC Chipsets.

●

The secondary interface, the Address/Address Multiplexed (or A/A Mux) Interface, is

designed to be compatible with current Flash Programmers, for production line

programming prior to fitting the device in a PC Motherboard.

The memory is supplied with all the bits erased (set to ’1’).

In order to meet environmental requirements, ST offers the M50FLW040A and

M50FLW040B in ECOPACK® packages. ECOPACK® packages are Lead-free and RoHS

compliant. ECOPACK is an ST trademark. ECOPACK specifications are available at:

M50FLW040A датащи(PDF) 7 Page - STMicroelectronics