A semiconductor memory device with low power consumption in driving control signals of shift registers. This valve is typically a normally closed valve which is opened by application of nitrous oxide under pressure when the nitrous oxide delivery system is activated. Another instance of the same wireless key signal is received, its key-specific identifier is detected, and the stored signal transmission location is retrieved based on the detected key-specific identifier. The state fields in the index table object and the data segment objects facilitate the data recovery process.