US Patent 7519005 Single-wire communication bus for miniature low-power systems

A single-wire serial communications bus has a master device and one or more slave devices. The slave devices are addressed according to a predetermined addressing scheme in an address space. The master device starts a transmission with a number of line state changes which define a clock period to be used by the slave devices in clocking and framing the serial data. This permits omitting a clock line, thus saving a pin and saving printed circuit board space. This also permits the slave devices to shut down their own clocks during periods of inactivity on the bus, thus saving power. Likewise the master device is able to shut down its clock during periods of bus inactivity.