Image sensor synchronization without input clock and data transmission clock

An endoscopic system for use a controlled light environment comprising:

• an endoscope comprising a lumen and an image sensor;
• an emitter;
• a fiber optic cable;
• a control circuit in electronic communication with the image sensor and the emitter;
• wherein the control circuit will control a duty cycle of the emitter in response to signals that correspond to the duty cycle of the emitter;
• wherein the image sensor comprises:
• input and output pads wherein the pad count is reduced by not having a dedicated synchronization clock pad;
• a frame period that is divided into three defined states:
• a rolling-readout state during which image data is output through the pads,
• a service-line state during which non-image data is output through the pads, and
• a configuration state during which the instruction data is received by the image sensor through the pads,
• wherein signal transitions are encoded within the output data from the image sensor in correspondence to the frame period states.