M35B32 datasheet(6/44 Pages) STMICROELECTRONICS

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Description

M35B32

6/44

DocID18391 Rev 4

Description

The M35B32 is a 32-Kbit electrically erasable programmable memory (EEPROM) accessed

through the SPI bus.

The M35B32 is able to save and store up to 256 bytes within a very short time with the help

of the Event sector, this feature being convenient in cases of an unexpected power loss or if

an urgent data storage is required. The fast storage is performed with a very low energy

budget as the Program time lasts less than 1 ms and as the supply voltage can be as low as

2.5 V associated with a low Programming current (the M35B32 is based on EEPROM cells,

energy-saving technology when compared to the Flash technology).

Memory organization

The M35B32 is split into two sectors:

•

the Data sector: standard EEPROM which can be written(a) by page (1 to 256 bytes at

a time) with a standard write time and a standard retention time,

•

the Event sector: data bytes which can be programmed(b) by page (1 to 256 bytes at a

time) with a fast programming time and a limited retention time.

The time required to update data is significantly reduced by the Page size (256 bytes) as a

page is updated in a single shot.

Both Data sector and Event sector can be erased either a page at a time (using the Page

Erase instruction) or a sector at a time (using the Sector Erase instruction).

The size of each sector is defined by the user.

Figure 1. Logic diagram

a. Write cycle = 2 cycles = Erase + Program

b. Program cycle = single cycle (a Write cycle includes two cycles: Erase cycle + Program cycle)

RESET

AI15472

VCC

M35B32

VSS

M35B32 数据表(PDF) 6 Page - STMicroelectronics