M29W640FT, M29W640FB
1 Summary description
1
Summary description
The M29W640F is a 64 Mbit (8Mb x8 or 4Mb x16) non-volatile memory that can be read,
erased and reprogrammed. These operations can be performed using a single low voltage (2.7
to 3.6V) supply. On power-up the memory defaults to its Read mode.
The memory is divided into blocks that can be erased independently so it is possible to
preserve valid data while old data is erased. Blocks can be protected in units of 256 KByte
(generally groups of four 64 KByte blocks), to prevent accidental Program or Erase commands
from modifying the memory. 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 required to control the memory
is consistent with JEDEC standards.
The device features an asymmetrical blocked architecture. The device has an array of 135
blocks:
8 Parameters Blocks of 8 KBytes each (or 4 KWords each)
127 Main Blocks of 64 KBytes each (or 32 KWords each)
M29W640FT has the Parameter Blocks at the top of the memory address space while the
M29W640FB locates the Parameter Blocks starting from the bottom.
The M29W640F has an extra block, the Extended Block, of 128 Words in x16 mode or of 256
Byte in x8 mode that can be accessed using a dedicated command. The Extended Block can
be protected and so is useful for storing security information. However the protection is not
reversible, once protected the protection cannot be undone.
Chip Enable, Output Enable and Write Enable signals control the bus operation of the memory.
They allow simple connection to most microprocessors, often without additional logic.
The V
PP
/WP signal is used to enable faster programming of the device, enabling multiple word/
byte programming. If this signal is held at V
SS
, the boot block, and its adjacent parameter block,
are protected from program and erase operations.
The device supports Asynchronous Random Read and Page Read from all blocks of the
memory array.
The memories are offered in TSOP48 (12x 20mm) and TFBGA48 (6x8mm, 0.8mm pitch)
packages.
In order to meet environmental requirements, ST offers the M29W640FT and the M29W640FB
in ECOPACK
®
packages. ECOPACK packages are Lead-free. The category of second Level
Interconnect is marked on the package and on the inner box label, in compliance with JEDEC
Standard JESD97. The maximum ratings related to soldering conditions are also marked on
the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at:
The memory is delivered with all the bits erased (set to 1).
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