Guidance in designing a Synchronous NAND Flash (ONFI 2.x/Toggle-Mode) interface.

[Altera_Forum]

I am looking into the possibility of rolling my own external memory interface (Controller and PHY) to support Synchronous NAND Flash protocols. Either ONFI 2.x (Micron and others) or "Toggle"-mode (Toshiba and others). The Altera target device will be Cyclone V. I have successfully designed for an asynchronous NAND Flash but that was pretty easy. I could go and purchase IP in the market but we have some very special requirements for the controller. The design of the PHY, I hope, can take advantage of Altera's ready-to-go Megafunctions. The trouble is, I need a guide to what Megafunctions I need to use and how best to use them. Although not appropriate since it is for Stratix III and IV, the "External Memory Interface Handbook Vol 5: Section I - Implementing Custom Memory Interface PHY", EMI_CUSTOM-1.1, Dec 2010 is what I am looking for. For those who are not familiar with ONFI 2.x "synchronous" NAND Flash interface, it is spec'ed to "leverage" already familiar DDR techniques.  

 Thanks,  Mark Boston, MA  BTW, I am not an "Altera beginner". I guess I need to edit my profile sometime:oops:

[Altera_Forum]

HI Mark, 

 Did you do any progress with this. I am designing my own custom controller with toggle interface but I need to figure out the PHY part. The only thing I know is that I need to use ALT_DQ_DQS megafunction in Arria5. The problem is that for address/command phases I need to have direct access to the DQ bus and while doing data Input output I need all the functionality in this megafunction to make DQS based sampling work. I am wondering how you managed to do this. It would be great if you could tell me if you found any robust solution for interfacing to any PHY/Megafunction for sending these flash signals from internal logic to the flash memory outside fpga.

[Altera_Forum]

I have not progressed on this at all. Main reason is that our product requirements are not yet forcing the situation, not yet!. But you are correct in that you will have to work directly with the PHY "modules" like ALT_DQ_DQS. Sorry for the non-answer. This seems like a ripe area where Altera could help out by providing a megafunction. 

 -Mark