Interfacing with CMOS flash memory - possible?

Using Arduino Microcontrollers
1

I have a few chips kicking around from a previous life...
They are 32 pin DIP 256kx8 5V CMOS flash memory, such as the Winbond W49F002U.
The datasheet is pretty comprehensive and it looks like it might work.
Could they be used for data storage on an AVR?
Maybe create a separate sketch to write data to the chip, then use that data with the "actual" sketch.
That would provide 2Mbit of storage and about 10k reflashes.

2

blast from the past. i have used that kind of chip with great success on many different avrs. there are several approaches:

  1. use avr that has bus like m8515, m128, etc
  2. use smaller avr like m8 or m328 with 4040 counter chip to supply address
  3. use bigger chips like m2560 to emulate address and data with io pins

be aware that reading is easy like any eprom but writing requires special sequence of commands.

3

Sweet, Thanks John

Yeah, I was thinking 1284P - I can probably spare a dozen pins for this purpose.

4

Uhm..... You do know that you can get cheap I2C EEPROMs now, right? That's a 2 mbit part - 2 mbit I2C or SPI EEPROM chips are in the $2-5 range. Those only use 2 pins (for I2C), or 4 (for SPI)
http://www.digikey.com/product-search/en/integrated-circuits-ics/memory/2556980?k=&pv142=115&FV=fff40027%2Cfff80434%2C2680042%2C26802e4&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

5

Doc,

Thank you, yes, I actually already have one, but I just found these in a box and the gears started spinning.
Of course I2C mem is hard to beat, only two pins, libraries available...
I was just wondering about these little guys. Seems like a shame to let them go to waste...

6

Or, use F-RAM directly with this code: GitHub - LowPowerLab/SPIFlash: Arduino library for read/write access to SPI flash memory chips

Ray