2 ms·
That's often true on a scale of microseconds, but USB input devices are polled at intervals on millisecond scale.
by wtallis 5y ago
That's often true on a scale of microseconds, but USB input devices are polled at intervals on millisecond scale.
- cma 5y agoOnly in the slowest modes. It is possible to go faster than the 1ms poll rate, though it is back to interrupts: > Transaction latency > For low speed (1.5 Mbit/s) and full speed (12 Mbit/s) devices the shortest time for a transaction in one direction is 1 ms.[6] High speed (480 Mbit/s) uses transactions within each micro frame (125 µs)[7] where using 1-byte interrupt packet results in a minimal response time of 940 ns. 4-byte interrupt packet results in 984 ns. https://www.wikipedia.org/wiki/USB_(Communications) https://www.wikipedia.org/wiki/USB_(Communications)