| 摘要 |
PURPOSE:To attain the diagnosis without using an exclusive hardware by setting only one of two registers of a duplex structure under an available state while the other register is undergoing the diagnosis of its normalcy. CONSTITUTION:The duplex registers 1 and 2 always receive the same data when they receive accesses from a host device. A control means writes the diagnosing data to the 1st one of both registers 1 and 2 for diagnosis of the normalcy of the 1st register. While the error data is written to a 2nd register to produce a parity error. Thus, only a 1st register is available at diagnosis and therefore the diagnosis is possible without using any exclusive hardware. |
