| 摘要 |
PURPOSE:To reduce the hardware quantity of a low-order device and to simplify the processing of a host device, by writing a self-diagnosed result on the memory in the host device by the low-order device. CONSTITUTION:A field representing a memory address in the host device 1 to which the self-diagnosed result is reported is provided in a command which instructs the execution of self-diagnosis from the host device 1. And the low- order devices 2-1-2-n receiving the command to instruct the execution of the self-diagnosis write the self-diagnosed results on the memory address instructed by the command in the host device 1. A processing control part 11 in the host device 1 obtains the self-diagnosis of the low-order device 2-1 by reading data in the area 12-1 of the memory 12, and performs the processing of the self- diagnosed result. Thus, since the self-diagnosed result of the low-order device 2-1 can be cleared by reading the content of the memory 12 in its own device, it is not required to make access to the low-order device 2-1 for the reading of the self-diagnosed result. |
