The RD9700 is "USB 2.0" and what they don't tell you is that it's actallly "USB 2.0 (FS)", i.e. the 12Mbps full speed mode.
It also comes in a 32-pin package, and comes from a shady-looking company (http://www.corechip-sz.com/ ) that has parts numbered 6872 and 6873, so the "RD6877" on the PCB of OP's clone suggests it might be a RD6877.
It also comes in a 32-pin package, and comes from a shady-looking company (http://www.corechip-sz.com/ ) that has parts numbered 6872 and 6873, so the "RD6877" on the PCB of OP's clone suggests it might be a RD6877.