US Patent 7644250 Defining pin functionality at device power on

An orientation detector within a device package is used to establish the device orientation. A host controller coupled to the device supplies a control signal to at least one of the pins on the device during a setup phase. The pin that receives the control signal is used for active signaling during normal operations of the device. Based on the control signal, the orientation detector generates an orientation signal within the device. An analog or digital selector circuit connects the pins to correct internal circuit components according to the device orientation.