Abstract: A decoding method for biphase-encoded data is provided. The decoding method includes detecting falling-edge transitions in the biphase-encoded data to decode according to a time difference (?t) between each two adjacent falling-edge transitions and the logic value of previous bit. When ?t is 1 bit period and previous bit is logic 1, it's determined that present bit is logic 1. When ?t is 1 bit period and previous bit is logic 0, it's determined that present bit is logic 0. When ?t is 1.5 bit periods and previous bit is logic 1, it's determined that present and next bits are both logic 0. When ?t is 1.5 bit periods and previous bit is logic 0, it's determined that present bit is logic 1. When ?t is 2 bit periods and previous bit is logic 1, it's determined that present and next bits are logic 0 and 1 respectively.