TEST MODE CHANGEOVER METHOD AND TEST MODE CHANGEOVER DEVICE FOR IC FOR FDD, FDD DEVICE

摘要

PROBLEM TO BE SOLVED: To surely prevent an IC for FDD device from being changed over to a test mode after it is made to enter into a normal mode. SOLUTION: The changing over of the IC 1 for FDD device into the test mode is carried out, provided that there is the input of a test mode shifting command within a fixed period posterior to the applying of the power source.