在ds中BuildVendorRequest怎么样呀,哪位大侠知道?

我是用ds开发usb程序，但不知道如何读写register,
BuildVendorRequest这个函数到底怎么用呀，

我的源码如下:
NTSTATUS Fps200Device::writeRegister(int reg, unsigned char data)
{
PURB pUrb;
//USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
NTSTATUS status = STATUS_SUCCESS;
unsigned char p = (data << 8) | reg;
pUrb = m_Lower.BuildVendorRequest(NULL,
0,
0,//USB_TYPE_VENDOR|USB_DIR_OUT|USB_RECIP_DEVICE,
0,//FPS200_USB_WRITE_REQUEST,
(data << 8) | reg,
FALSE,
FALSE,
NULL,
0,
URB_FUNCTION_VENDOR_DEVICE);
status = m_Lower.SubmitUrb(pUrb);
return status;
}



[编辑 -  6/9/04 by  zj7310]

Fps200  的驱动不是已经提供了？