我现在在用tiny2451开发板做实验，我想把它的usb device改成usb host,以前在2440上非常容易修改，但是2451不一样了
修改的寄存器比较多：
PHYPWR 0x4C00_0084 0x0
PWRCFG 0x4C00_0060 (1<<4)
> URSTCON 0x4C00_0088 (0<<2)|(1<<1)|(1<<0)
> URSTCON 0x4C00_0088 (0<<2)|(0<<1)|(0<<0)
> PHYCTRL 0x4C00_0080 (0<<3)|(0<<2)|(1<<1)|(1<<0)
> UCLKCON 0x4C00_008C (0<<31)|(0<<2)|(1<<1)|(1<<0)
>
> Once I try to plug in a USB mass storage device (whose driver is present in
> kernel), I get the following error:
>
> usb 1-2: new full speed USB device using s3c2410-ohci and address 10
> usb 1-2: device descriptor read/64, error -62
> usb 1-2: device descriptor read/64, error -62
> usb 1-2: new full speed USB device using s3c2410-ohci and address 11
> usb 1-2: device descriptor read/64, error -62
> usb 1-2: device descriptor read/64, error -62
> usb 1-2: new full speed USB device using s3c2410-ohci and address 12
> usb 1-2: device not accepting address 12, error -62
> usb 1-2: new full speed USB device using s3c2410-ohci and address 13
> usb 1-2: device not accepting address 13, error -62
port 2插入U盘后的结果是这样的，各种修改还是不行，请大神指教有没有成功的。
另想问一下，用usb host 1.1接usb hub扩展出来的四个usb性能好吗？想同时接两个usb设备，到时会有问题吗？谢谢，盼回复。
