Host communication circuit, client communication circuit, communication system and communication method

A client communication circuit that is adapted to be connected to a host communication circuit by means of a single signal wire, the client communication circuit being configured

• to generate a sync signal with one or more sync pulses, the generation of each sync pulse based on a detection of a significant voltage change within a voltage modulated signal received via the signal wire from a connected host communication circuit;
• to generate a client clock signal based on the sync pulses of the sync signal, the sync pulses determining a clock cycle of a reference clock signal of the connected host communication circuit, wherein the client clock signal has a higher frequency than the sync signal;
• and
• to perform a current modulation on the signal wire by generating a current modulated signal based on the client clock signal and on data to be transmitted from the client communication circuit to the connected host communication circuit, wherein a current modulation based on the data to be transmitted is performed only after a predetermined settling time after one of the sync pulses until the respective following sync pulse, for each clock cycle of the reference clock signal respectively the sync signal.

A method for communication between a host side and a client side, which are connected to each other by means of a single signal wire, the method comprising:

• on the host side, performing a voltage modulation on the signal wire by generating a voltage modulated signal based on a reference clock signal;
• on the host side, in a first period of a clock cycle of the reference clock signal, generating the voltage modulated signal with a significant voltage change based on a clock edge of the reference clock signal;
• on the host side, in a second period of the clock cycle, generating the voltage modulated signal with a voltage variation that is basically constant during said second period, wherein the clock cycle consists of the first period and the second period, and wherein the first period is significantly shorter than the second period;
• on the client side, generating a sync signal with a respective sync pulse based on a detection of the significant voltage change;
• on the client side, generating a client clock signal based on the sync pulses of the sync signal, wherein the client clock signal has a higher frequency than the sync signal;
• on the client side, performing a current modulation on the signal wire by generating a current modulated signal based on the client clock signal and on data to be transmitted from the client side to the host side, wherein a current modulation based on the data to be transmitted is performed only after a predetermined settling time after one of the sync pulses until the respective following sync pulse, for each clock cycle of the reference clock signal respectively the sync signal;
• and
• on the host side, demodulating the current modulated signal.