Good day Freaks!
I have a question that I would to get an opinion. As some may know, my big project I have been working on is an arcade machine. I have the majority of the systems prototyped with breadboards (audio, video, and controller input) and working great. I have slowly been working on getting things together for the main driver board.
However, recently this week I have been prototyping the audio system. Now this works great in it's current state (I have only been at it for about a week, so it's still pretty early in breadboard stage).
For the final design, I would like to integrate an SPI Flash memory chip that will go on the cartridge for the games.
Now the problem I seem to have encountered in my searching is that SPI Flash chips all seem to be 3.3v logic (the ones I found on DigiKey and Mouser). I would like to integrate at least 2MB (16MBit) but preferably something more like 4MB or even 8MB.
Currently, my video driver is based on 5 volt logic and is using an ATmega1284. I have this board already designed and routed. It is currently the only major system that is actually routed.
I would like all my main chips to be running the same logic level as the game cartridge CPU will communicate with the audio and video systems via SPI.
Most modern SPI Flash chips I've found are 3.3v volt logic and my current design is 5 volt. I see a few options here:
- Scrap my current video driver design which uses 5 volt logic and develop everything (audio and video) with ARM technology
- Use resistor dividers on the logic/supply pins for SPI Flash chips?
I have yet to get a stable image using an ARM processor (was testing on a D21 and it had way too much jitter) and that is why my current design uses an AVR8, as I was able to get perfect cycle timing using assembly.
Either way, I would still like to get VGA video working with an ARM but at this point I am just looking at a way to learn more options in this.
I really hope this isn't just a completely stupid question. Thanks for your help!