Serial Flash

I don't know what the difference is, but you might shop by what is available in the size you need, and then decide if it will do the job. When I look at what I could have on my desk tomorrow from Digikey, Atmel's offerings in your size range (I assume you mean Bytes not bits) are from their dataflash series only.

=46rom Four serial Flash families to meet all of your needs

The AT25Fxxx, AT25FSxxx and AT25DF/26xxx series of products are pin compatible to our complete offering of SPI serial EEPROMs. This gives you the flexibility of increasing your memory size from a low- density serial EEPROM device to a serial Flash without any changes to your board layout.

The full-featured AT45DBxxx DataFlash=AE family is taking SPI serial Flash to the next level. Advanced features to further enable system integration, robustness and cost reduction include a 128-byte security register, individual sector protection, and a permanent lockdown feature. This popular page erase architecture allows key software routines, parameters and user data to be stored more efficiently, so that more memory space isn't wasted by allocating large sectors for different types of code or data.

Alan Nishioka

"DataFlash is a low pin-count serial interface for flash memory. It is an Atmel proprietary interface, compatible with the SPI standard." as per Wikipedia

Serial flash conforms to an industry standard serial interface protocol (SPI).

Serial flash implies the same product is available in the same packaging as other manufacturers products of a similar configuration and memory size (This is implied but in reality it is not always the case). You really need to read the data sheets, to determine which is more appropriate to your needs. However if your implementation is more general purpose, choose the component that fits the memory requirements and design the interface accordingly.

Jack a écrit :

Hi,

There are actually 4 series:

If you write the whole data at once, you can use any.

ST (now known as Numonyx) -> M25Pxx, M25PExx, M25PXxx, M45PExx Winbond W25Xxx Macronix M25Lxx AMIC A25L0xx SST 25VFxxx, 26VFxxx Spansion S25FLxxx

For 3 MB, you need at least 24 Mbits, so you must choose a 32 Mbits part.

Winbond has some cheap and big serial flash ICs:

I don't know if this will be produced any longer, because Digikey says the stock won't be filled when depleted, but there are some pin compatible parts from other manufactures, too, like STMicroelectronics, or this one:

I think DataFlash has some more features, like smaller block size when programming, but is available from Atmel, only.

Branding. Older Atmel DataFlash was different, it had a ping-pong RAM buffer, so you could stream to it continually. Now I think they call more memory DataFlash

See

AT45DBxx is the family with RAM buffers AT25DF is more conventional SPI Flash memory

Lots of companies make SPI flash, and there are also SD cards, if you need a removable memory.

-jg