Device description
UM0453
2 Device
description
The M29W128GH and M29W128GL are 128 Mbit (8 Mb x16 or 16 Mb x8 or) non-volatile
Flash memories that can be read, erased, and reprogrammed. These operations can be
performed using a single low voltage (2.7 to 3.6 V) supply. Upon power-up, the memory
defaults to read mode.
The memory array is divided into 64 Kword/128 Kbyte uniform blocks that can be erased
independently so it is possible to preserve valid data while old data is erased. 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
managing 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 are identified.
The command set required to control the memory is consistent with JEDEC standards.
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 M29W128GH and M29W128GL support asynchronous random read and page read
from all blocks of the memory array. The devices also feature a write to buffer program
capability that improves the programming throughput by programming in one instance a
buffer of 32 words/64 bytes. The V
PP
/WP signal can be used to enable faster programming
of the device.
The M29W128GH and M29W128GL have an extra block, the extended block, of 128 words
in x16 mode or of 256 bytes in x8 mode that can be accessed using a dedicated command.
The extended block can be protected and, therefore, is useful for storing security
information. However, the protection is not reversible; once protected, the protection cannot
be undone.
The device features different levels of hardware and software block protection to avoid
unwanted program or erase (modify):
●
Hardware protection:
–
The V
PP
/WP provides hardware protection of the highest and lowest block on the
M29W128GH , M29W128GL, respectively.
●
Software protection:
–
Volatile protection
–
Non-volatile protection
–
Password protection
