I'm designing custom systems with ADSP-21478 and BF-592 processors, and I'd like to boot my software from SPI Flash, utilising the VDSP++ Flash Programmer utility. I have successfully done so using the M25P16 parts that are used in the EZ-kits with the flash drivers provided.
Unfortunately it looks like these parts are being phased out, being labelled 'Obsolete' or 'Last Time Buy' at all of the large electronics parts distributors. Can Analog Devices recommend an alternative part to use in place of the M25P16? Ideally it would be pin and package compatible and work with the provided drivers.
Which part will be used in the BF-592 and ADSP-21479 EZkits going forward?
Thank you very much.
Welcome to the club. Serial flash manufacturers are constantly changing their product lines and updating features. Currently Micron & Cypress (previously Spansion) parts are in play. Micron seems to have bailed on small devices and Cypress also seems to be moving in this direction. I think this is because small serial flash is too inexpensive for their tastes.
The good news is that you generally just need to find a footprint compatible part. All devices are read compatible.
The bad news is that flash is not necessarily universally programmable from different suppliers and they may not support some optional features that you may like.
More bad news is that many of the larger memory devices are not readily available in narrow SOIC-8 packages which is the most common footprint for 16Mb and smaller parts.
Many new devices are now supporting SFDP. This is aimed at making it possible to write different devices with a universal programmer. For those familiar with parallel flash, this is similar to CFI. However, SFDP came much later than CFI, so boards designed with earlier parts probably don't have SFDP programming support. Small serial flash devices are also less likely to implement SFDP.
It seems to me that perhaps the most logical migration might be to either Winbond or Adesto. Adesto bought the flash line from Atmel a few years ago. Both of these companies seem interested in this business. There also a few others as well, for example Microchip bought SST. The replacement parts will take modifications to the programming utility.
It would probably help if the ADI tools team in Nashua jumps in with their plan. They have been using Winbond on some of the newer designs.
Our solution was to buy an 18 month supply while everything sorts itself out. This is quickly becoming a non-option as supply is drying up. Our customers are not generally impacted because we supply bootloaders that abstracts the flash from the programming.
Thank you very much for your explanation of the situation, including things like SFDP and CFI. It sounds like the best option for me will be to do the same as you - securing a supply of M25P16s from alternative sources and wait it out in the hope that the ADI team will step up at some stage with recommended alternatives and ideally, drivers.