DATA ACCESS SYSTEM AND INFORMATION PROCESSOR

摘要

A data change detector (102) is provided for detecting that a data bus (120) is changed to a high level or a low level from a high impedance status or a middle potential status, and for outputting a data change detection signal which indicates that the change has been detected. When the data change detector (102) outputs the data change detection signal, data is fetched by a control circuit (103) from the data bus (120).