A semiconductor memory device, in which peripheral circuits are arranged in a cross area of a semiconductor chip composed of the longitudinal center portions and the transverse center portions, and in which memory arrays are arranged in the four regions which are divided by the cross area. The method is used to generate a wobble clock and an absolute time in pre-groove clock for controlling the operation of an optical disk drive. The data processor stores this time difference as a detection time of light emission. The method includes determining that the one or more event processing paths contain an independent rule, wherein an independent rule includes a rule or a rule subset where data for processing of the rule or rule subset is accessible by a client computing device. Embodiments include stepper motors having very fine adjustments so that size of tuning steps are substantially reduced for more precise tuning. The systems and methods permit, at the beginning of a communication event, the determination of a time limit for the event based on the available balance in a prepayment account associated with the event.