A host-to-host chip includes: first and second ports coupled to first and second hosts respectively; and a host-to-host control circuit coupled to the first port and the second port. When the host-to-host chip is coupled to the second host, the host-to-host control circuit identifies whether the second host is an i-Phone or an Android smartphone. If the host-to-host control circuit identifies that the second host is an i-Phone smartphone, in response to a command from the host-to-host control circuit, the second host switches to host role from device role, and the host-to-host control circuit controls whether data is transmitted between the first host and the second host via a DMA path. If the host-to-host control circuit identifies that the second host is an Android smartphone, the host-to-host control circuit determines that data is transmitted between the first host and the second host in a pass-through mode.