Operating method of human interface device

An operating method of a human interface device, the operating method comprising:

• estimating an accumulated bit number of bits between a first bit of a SYNC field and a bit immediately preceding an End-of-Packet of a data packet in a USB data stream according to a clock signal and counting an oversampling number of the clock signal;
• comparing the oversampling number and M times of the accumulated bit number when the accumulated bit number exceeds a predetermined value;
• determining a correction parameter according to a ratio between the oversampling number and the M times of the accumulated bit number;
• and
• processing raw data detected by the human interface device according to the correction parameter;
• and
• calculating detected information according to the processed raw data.

An operating method of a human interface device, the human interface device being wirelessly coupled to a programmable oscillator and comprising an oscillator, a demodulator and a receiver, the operating method comprising:

• estimating an accumulated bit number of bits between a first bit of a SYNC field and a bit immediately preceding an End-of-Packet of a data packet in a USB data stream according to a clock signal and counting an oversampling number of the clock signal;
• comparing the oversampling number and M times of the accumulated bit number when the accumulated bit number exceeds a predetermined value;
• decreasing a frequency of the clock signal when the oversampling number is larger than the M times of the accumulated bit number;
• increasing the frequency of the clock signal when the oversampling number is smaller than the M times of the accumulated bit number;
• receiving a packet for communication request from the human interface device;
• transmitting a packet for reply to the communication request with a payload comprising a synchronous signal;
• receiving the synchronous signal by the receiver;
• generating an oscillation frequency by the oscillator;
• mixing the synchronous signal and the oscillation frequency to retrieve a sampled signal;
• demodulating the sampled signal by the demodulator to retrieve an error correct signal;
• and
• calibrating, using the error correct signal, detected information obtained according to the oscillation frequency,
• wherein the synchronous signal corresponds to the trimmed frequency of the clock signal.