| 摘要 |
<p>PURPOSE:To disconnect an abnormal part when a supply power source from a back up power source is abnormal and to easily search the element of the SRAM of an abnormal current by dividing the power source line of the back up power source of the SRAM of a surface mounting package directly mounted on a printed board into plural and providing parts to be disconnected respectively. CONSTITUTION:A battery, and a system power source are connected to a non- volatile memory circuit consisting of plural SRAMs through a switching circuit C so as to input a timing signal. The power source lines L1, L2, L3 to which the back up power source divided into three circuits respectively is supplied are disposed. The SRAMs 11-1n are connected to this line L1, the SRAMs 21-2n to the line L2 and SRAMs 31-3n to the line L3, respectively. In the respective parts of the lines L1, L2, L3, jumper wires J1, J2, J3 of the parts which can be disconnected and a corresponding metal pin P are disposed. When the back up power source is abnormal, the lines L1-L3 are selected by the wires J1-J3 to easily search the abnormal element.</p> |
