For the handheld device, it becomes being smaller and having more functionalities,
USB 2.0 interface is likely to be used more frequently with huge capacity of storage device, HDD. Comparing other interface like as
CF, it requires less pins to connect with peripherals, only 4 pins, D+, D-, ground and Vcc.
To get the maximum speed of transfer it's best way to make connection directly between the USB2.0 controller and storage device. But some of hardware design may cause bottleneck of transferring speed(see Fig.1.). I'll deal how to improve the speed of accessing mass storage device, HDD, with USB2.0.
