Freescale Semiconductor TWR-MCF52259-Ethenet - page 92

TM
Software – General Concepts
The General USB Process
How Data is Transferred in USB
Frames are made up of transfers, which are made up of
transactions, which are made up of packets. The USB
host schedules these 1mS frames when communicating
with the low and full speed devices.
Frame
Transfer Transfer
Transaction Transaction Transaction Transaction
Packet 1 Packet 2 Packet 3
Packet 1
Packet 2 Packet 3
Packet 1
Packet 2 Packet 3 Packet 1 Packet 2
Packet 3