Considering USB is a serial bus you're only going to get one bit at a time no matter what chip you use! =) kchristie is right juat send two bytes at the same time, the data is sent in discrete packets much bigger (usually) than 8 bits at a time anyways. Usually you stuff the buffer as fast as you can and it sends a few hundred bytes at a time while the buffer is refilling. If you try to transmit individual bytes or words at a time the packet overhead becomes better than half of the data stream and your available bandwidth drops to less than you can do on a normal serial port pretty fast.