US Patent 7983099 Dual function compatible non-volatile memory device

A dual function memory device architecture compatible with asynchronous operation and synchronous serial operation. The dual function memory device architecture includes one set of physical ports having two different functional assignments. Coupled between the physical ports and core circuits of the memory device are asynchronous and synchronous input and output signal paths or circuits. The signal paths include shared or dedicated buffers coupled to the ports, asynchronous and synchronous command decoders, a network of switches, and a mode detector. The mode detector determines the operating mode of the dual function memory device from a port, and provides the appropriate switch selection signal. The network of switches routes the input or output signals through the asynchronous or synchronous circuits in response to the switch selection signal. The appropriate command decoder interprets the input signals and provides common control logic with the necessary signals for initiating the corresponding operation.