Byte stuffing circuit and byte stuffing method

A byte stuffing circuit, comprising:

• an input gate, receiving a first data stream and generating a second data stream according to the first data stream, wherein a first size of the first data stream is N bytes, and a second size of the second data stream is 2N bytes, wherein N is a positive integer;
• a logic circuit, coupled to the input gate, comprising:
• an Xth stage logic gate, overwriting the Xth byte with a first stuffing byte in response to the Xth byte of the second data stream matching a first flag byte and inserting a second stuffing byte into an (X+1)th byte of the second data stream, wherein X is a positive integer between 1 and 2N−1;
• a remnant register, storing a remnant data stream;
• a remnant gate, coupled to the logic circuit and the remnant register, wherein the remnant gate combines the remnant data stream and a first part of the second data stream to generate a third data stream and configures a second part of the second data stream as the remnant data stream;
• and
• an output gate, coupled to the remnant gate, outputting the third data stream.