Universal Serial Bus - Latency

Latency

For USB1 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. USB2 high-speed (480 Mbit/s) uses transactions within each micro frame (125 µs) where using 1-byte interrupt packet results in a minimal response time of 940 ns. 4-byte interrupt packet results in 984 ns.