ttl to usb3.0 speed


I’m trying to understand if it is possible to count 20ns ttl signals with the computer.
Can I use standart ttl to USB convrter? does this converters are fast enough?


I can’t answer, but I suspect the answer is “no”. One detail to consider is that the USB driver itself is not running continuously, the driver runs upon hardware interrupt on CPU0…many different hardware drivers are being run one at a time on that CPU core, constantly switching in and out of context. USB can give you bursts of quick response, but there is virtually no way to get a consistent fast response.

Now imagine that your source of 20ns TTL signals has a driver too, and that the driver can’t run at the same time as the USB driver, or runs on a different core without a guarantee of timing. Any I/O results would need to be saved into memory, the TTL signal source driver swapped out of context, and the USB driver swapped into context.

To find a solution you may need to post a much more detailed description of what you want to accomplish regarding the source of the TTL signal and what it is that needs to consume that signal.

Thanks for your answer :)