Patent ID: 7191267

Claim:
An electronic device system having a controlling device and a controlled device interconnected via a data bus which complies with a predetermined communication format and which allows data to be exchanged between the devices, said electronic device system comprising: means for causing said controlling device to transmit a command to said controlled device over said data bus in a transaction; means for allowing said controlling device to receive a response returned within a first predetermined period by said controlled device over said data bus in response to the transmitted command during said transaction; means for judging whether the response received by said controlling device is an interim response corresponding to when said controlled device determines that the transmitted command has been received and that a transmission of a final response is impossible within a second predetermined period less than the first predetermined period; and means for immediately terminating said transaction without waiting for reception of said final response from said controlled device if said judging means judges the response received by said controlling device to be said interim response, said means for terminating including means for recognizing a command transmission error when said controlling device does not receive a response within said first predetermined period.