Patent ID: 8171193

Claim:
A master communication circuit communicatively connected to a slave communication circuit, comprising: a first output circuit that outputs a first output signal of one logical level to initiate transmission of either a first logical value or a second logical value from the master communication circuit to the slave communication circuit; a timer circuit that can detect a first time, the timer circuit starting a detecting operation of the first time when the first output signal is output to initiate transmission of the first logical value from the master communication circuit to the slave communication circuit; a second output circuit that outputs a second output signal of another logical level when the timer circuit detects the first time, wherein the output of the first output signal instructs the slave communication circuit to start a detecting operation of a second time longer than the first time, and wherein the slave communication circuit receives the first logical value if the slave communication circuit does not detect the second time before the second output circuit outputs the second output signal, and wherein the slave communication circuit receives the second logical value if the slave communication circuit detects the second time.