Start bit detecting circuit

摘要

A start bit detecting circuit is disclosed, which employs a waveform reshaper, a detection and start circuit and a decision circuit. The waveform reshaper has threshold values T+ and T-. The detection and start circuit starts the start bit detecting circuit upon detection of a predetermined pulse width. The decision circuit judges, for a plurality of decision points, coincidence between the input signal and a specific pattern having a start-signal element, which comprises a plurality of bits.