1. A system, comprising a PC system and an embedded subsystem, the PC system comprising a host system, a power source, an Embedded Controller (EC) specific to the PC system, a first transmission interface, a second transmission interface and an input device, the power source being connected to the embedded subsystem, the host system and the EC, respectively, and the EC being connected to the embedded subsystem through the first transmission interface and to the host system through the second transmission interface, wherein the EC is configured to establish, in response to receipt of a first switching instruction, communication with the embedded subsystem such that the embedded subsystem is enabled to process input data from the input device connected to the EC and to transmit the input data obtained from the input device to the first transmission interface, and is further configured to transmit, in response to receipt of a second switching instruction, the input data obtained from the input device to the second transmission interface such that the host system is enabled to process the input data, wherein the first switching instruction is triggered by detecting that the host system is disabled while the embedded subsystem is enabled, and the second switching instruction is triggered by detecting that the host system is enabled while the embedded subsystem is disabled; and the embedded subsystem is configured to receive the input data from the first transmission interface, process the input data and perform an operation corresponding to the input data; wherein sharing of the input device between the embedded subsystem and the host system is achieved by the EC, wherein, the embedded subsystem is separable from the system, such that the embedded subsystem and the PC system, upon separation, are capable operating independently of each other, wherein the embedded subsystem comprises a personal digital assistant or a mobile phone, and wherein the embedded subsystem further comprises an input device processing module and a virtual input device driving module, wherein: the input device processing module is configured to receive the input data from the first transmission interface and to parse the type of the input data from the input data for generating data type information; and the virtual input device driving module is configured to convert the input data into data executable by the embedded subsystem based on the data type information.