The solid-state imaging device includes a DA converting circuit generating a reference voltage to be used for an AD conversion. A point coordinator station determines whether at least one of upstream traffic and side-stream traffic is scheduled to be transmitted from at least one non-PC station At least one available TO is allocated to each selected non-PC having at least one traffic to transmit. The write circuit operates on a positive power supply voltage provided by a host computer, and on a negative power supply voltage generated by a programmable DC\u2014DC converter mounted on a hard disk drive’s card. A run length field may be used to indicate the length of the second run field.