USB_CMD
wrl(USB_CMD, rdl(USB_CMD) & ~USB_CMD_RUN);
wrl(USB_CMD, rdl(USB_CMD) | USB_CMD_RESET);
while (rdl(USB_CMD) & USB_CMD_RESET);
wrl(USB_CMD, rdl(USB_CMD) | USB_CMD_RESET);
while (rdl(USB_CMD) & USB_CMD_RESET);