| 摘要 |
PURPOSE:To facilitate diagnosing troubles of a two-way bus and an interface circuit, by performing the data turn-back test on the two-way bus by each device itself. CONSTITUTION:In case of the diagnosis for the data write and transfer operation, a bus interface controlling circuit C10 of a master device sets write data for test and the device address of the master device itself to a data output register C6 and an output address register C7, respectively and indicates an input/ output controlling circuit C9 with an input/output operation controlling signal B3 to write and transfer data to a slave device. The circuit C9 generates the signal B3 as the slave device and inputs data on a data bus A1 to a data input register C5 and reports it with the signal B3 that data is inputted to the circuit C10. The circuit 10 inputs data from the register C5 and collates it with write data to perform the diagnosis. The diagnosis for the read and transfer operation of data is performed similarly. |
