On 14.07.22 09:06, gnuarm.del...@gmail.com
> On Wednesday, July 13, 2022 at 9:53:55 AM UTC-4, Josef Moellers wrote:
>> On 13.07.22 15:36, gnuarm.del...@gmail.com
>>> On Wednesday, July 13, 2022 at 2:31:30 AM UTC-4, Josef Moellers wrote:
>>>> On 12.07.22 17:23, DJ Delorie wrote:
>>>>>> Anyone using Efinix parts? They look ok, even if they don't have a
>>>>>> lot of package offerings.
>>>>> I checked into them a little while back, hoping for 5v tolerance, but
>>>>> they didn't have it.
>>>> Are there ANY FPGAs that have 5V tolerance?
>>>> I'm looking for one to replace an FDC9266.
>>> Unless you use a very, very obsolete device, you won't find 5V tolerance in any FPGAs. On inputs, 5V tolerance is easy to add, using just a pair of resistors as a voltage divider. On output, you will need to use at least a transistor to allow switching to 5V. But if you are working with TTL inputs, you don't need 5V drive, 3.3V drive should be enough.
>>> There are also ways to use resistors on outputs, to allow higher rise, by giving up something on the low end. What do you need to interface to?
>> It's a very old SingleBoardComputer with an HD64180 and lots of LS TTL
>> stuff. I need to interface to inputs (eg DMA requests), outputs (eg
>> address lines) and bidirectional (data lines). I am considering using
>> level shifters on the latter.
>> IIRC I had been asking here before and got the same answer you gave
>> above, but as DJ mentioned it, I thought I might be lucky today.
>> As I'm hopefully having lots of spare time in the near future
>> (retirement after almost 41 years in the IT industry), I guess I'll put
>> it all together and give it a try.
shifter using a FET and two pull-ups. That's what I'll (probably) use,
at least for the bidirectional signals. As only a one side is actually