| 摘要 |
PURPOSE:To make it possible to prevent a malfunction and to find instantly the abnormality of a program written on a ROM by inspecting written contents on the ROM, interrupting the execution of a program when the abnormality is found and displaying the state on an abnormality displaying part when an electronic key telephone set system is started up or is reset. CONSTITUTION:The program is started from the address 0 of the ROm 1 and is jumped to a test process part 9 when the system is started up or it is rest. At the inspection processing part 9, a check sum is calculated for every ROMN from N=1 to N=n and it is checked with the check sum of the ROMN which is written in advance at a check sum part 8 and when they are equal, the value of the N is updated and the above stated process is repeated until the N=n and when all of the content of the ROM1-ROMn are normal, the program is jumped to a system control part 4 and the primary process of the electronic key telephone set is started. When in inconsistency, the abnormality is displayed at an abnormality display part 7 and the interruption of the program is commanded. |
