Serial communication device, method thereof and communication system using the same

The serial communication device as claimed in claim s, wherein

• the second reception circuit comprises:
• a second T4 delay circuit that delays the received serial data signal DATA by the time period T4 equaling to or greater than (T1+T2), and outputs said delayed signal;
• a second input signal delay circuit that delays the output signal from the second T4 delay circuit by a predetermined time period and outputs said delayed signal;
• and
• a second data extraction circuit that extracts the first transmission data from the received serial data signal DATA and the output signal from the second input signal delay circuit, and outputs the extracted signal.

A serial communication method of a serial communication device that includes a first transmission/reception circuit and at least one second transmission/reception circuit connected with the first transmission/reception circuit in a transmission path, and performs serial communication by half-duplex communication between the first transmission/reception circuit and the second transmission/reception circuit,

• said method comprising the steps of:
• superposing a first superposition pulse having a second level on a portion of a clock signal input from outside having a first level according to binary first transmission data to be output to the second transmission/reception circuit, outputting a resulting serial data signal DATA to the transmission path, said clock signal being a binary signal, said second level being reciprocal to said first level;
• and
• superposing a second superposition pulse having the first level on a portion of the serial data signal DATA input from the transmission path corresponding to a duration of the clock signal having the second level according to binary second transmission data to be output to the first transmission/reception circuit.

A communication system comprising a serial communication device that includes a first transmission/reception circuit connected to a host device and at least one second transmission/reception circuit connected corresponding to slave devices able to communicate with the host device, and performs serial communication by half-duplex communication between the first transmission/reception circuit and the second transmission/reception circuit, said first transmission/reception circuit and said second transmission/reception circuit being connected with each other in a transmission path,

• wherein
• the first transmission/reception circuit of the serial communication device outputs a serial data signal DATA to the second transmission/reception circuit via the transmission path, said serial data signal DATA being generated by superposing a first superposition pulse having a second level on a portion of a clock signal input from the host device having a first level according to binary first transmission data to be transmitted from the host device to the slave device, said clock signal being a binary signal, said second level being reciprocal to said first level;
• and
• the second transmission/reception circuit of the serial communication device superposes a second superposition pulse having the first level on a portion of the serial data signal DATA input from the first transmission/reception circuit transmission path according to binary second transmission data to be output from the corresponding slave device to the host device, said portion corresponding to a duration of the clock signal having the second level.