A setup to use two Teensy 3.1 microprocessors to dump an Intel 28F400 NOR FLASH chip.
Always with the why? Because my ancient Dataman S4 doesn't support the 44-pin PSOP package, but I happen to have a socket that fits in a breadboard, so...
Oh, right. A single Teensy does have enough digital I/O, but only if you solder to the pads on the back. Not the most breadboard friendly. So I use one Teensy to set the address pins when commended over serial from the other Teensy.
Not as slow as you'd think. I set the Teensys to use 6,000,000 baud for serial, which works pretty well. You do have to overclock them to 96 MHz for that to work right.
Everything seems to work fine. I can dump the chip in about 45 seconds, which isn't blindingly fast, but is plenty quick for my purposes. I suspect I could optimize this process greatly by tightening up timings and getting creative with the address pins, but I don't think the complexity and development time is worth saving a few seconds the few times I will actually use this setup.
Writing the chip could certainly be faster (takes a couple minutes), but I think the driving factor is actually the program time on the array, not the sketchy interface provided here.
I'll get to it, probably. Honestly, just read the pin definitions in the source code, and follow the datasheet for the 28F400. It is pretty straightforward.
For now, just check out the wiring in the images below. Also check out that sweet Logic timing graph from a test dump!
