getafixx wrote:
Aren't the 29L3211 chips 16-bit? How do would you wire it to run in 8-bit mode
No, they aren't. You can set them in word or byte mode by tying pin 33 to GND or Vcc. Anyway, if they were 16 bit only, you could multiplex their output.
lidnariq wrote:
Also, I'm not altogether convinced you could have safely used it in a 5V system without level shifters or creative interpretation of the datasheet (by e.g. running it at 4V and relying on the 1V official overvoltage allowance)
No, you SHOULDN'T do that. The datasheet is crystal clear about that: absolute maximum 4V supply, typical 3.3V+10%. I don't know where you read that "
1V official overvoltage allowance", but the "[b]Absolute Maximum Ratings" can't be never exceeded. Anyway, the problem in using 29LV3211 is not the power supply (linear regulators are cheap as hell) but the Vih: the HIGH output level is, at least, 2.4V and at most, 3.3V and the TTL HIGH input level is, at least 2V. At first glance, you may ask where the problem is, because 2.4V is higher than 2V so the TTL logic after the 29LV3211 flash should sample the proper logic value, but this becomes fussy when there are long traces between flash and CPU, an edge connector and supply noise in each digital chip (specially, those synchronous to the MCLK). It's confirmed that 29LV3211 flash memories cause problems when used directly as a mask ROM replacement. They MIGHT work when used connected to some special chip like SA-1 or Super-FX, but not 100% reliable either.