Difference between revisions of "W25Qxx"

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[[File:W25Q128 Blocks.png|300px]]
 
[[File:W25Q128 Blocks.png|300px]]
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=== Sectors ===
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Each [[#Blocks|block]] is divided into a number of sectors.  In the W25Q128 each sector contains 4kB:
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[[File:W25Q128 Block Segmentation.png|300px]]
  
 
== Miscellaneous Links ==
 
== Miscellaneous Links ==

Revision as of 04:15, 26 February 2022

The W25Qxx is a common series of serial EEPROM chips.

Naming

These EEPROM chips are typically named "x25qxxx" where the first x indicates the manufacturer ("W" indicates Winbond) and the xxx after the Q indicates the size (in Mbits). A "W25Q128" is therefore 128 Mbits = 16 mB EEPROM manufactured by Winbond.

Connections

W25Qxx devices are available in a number of different packages, but the most common is a SOIC-8 package. These will typically have the following pinout:

W25Q128 SOIC-8 Pinout.png

It is worth noticing that many (if not all) of these devices can operate in two different "modes". Regular SPI with a MOSI/MISO pair of signals, and Quad-SPI where 4 data lines are being used.

Memory Layout

The memory in these devices are divided into blocks, sectors and pages.

Blocks

At the highest level is the "block". Blocks will typically be chunks of 64kB. In the case of the W25Q128 it will look like this:

W25Q128 Blocks.png

Sectors

Each block is divided into a number of sectors. In the W25Q128 each sector contains 4kB:

W25Q128 Block Segmentation.png

Miscellaneous Links