| 摘要 |
PURPOSE:To detect the capacity of the whole of a memory ending with a prescribed substrate by providing a control element on the transmission line from the memory substrate to a CPU and applying a mounting signal for mounting of a succeeding substrate to the control element to make the control element unoperated. CONSTITUTION:When memory substrates MP1, MP2-MPn are mounted up to the substrate MPn of a prescribed capacity, the mounting signal from a succeeding substrate does not come to a signal inverting circuit INVn of the last substrate. Therefore, a control element TRSn is controlled to be conductive, and information of the memory capacity is transmitted to the CPU. In other substraites, mounting signals from succeeding substrates come to signal inevrting circuits INV,and therefore, control elements are controlled to be unoperated. If a halfway memory substrate is pulled out, the line through which the capacity of the memory ending with the preceding substrate is transmitted is switched to the operating state. |
