DETECTION METHOD FOR FAILED MINOR LOOP OF BUBBLE MEMORY

摘要

PURPOSE:To detect a failed minor loop in a short time by permitting a magnetic bubble to circle under a condition that a bias magnetic field which is larger than a low limit bias magnetic field in which the magnetic bubble circle within a minor loop and which is smaller than the lower bias magnetic field in an integrated driving area. CONSTITUTION:If the magnetic bubble of test information is written in a minor loop mR which is formed in a magnetic bubble memory element and the low limit bias magnetic field in the total operation area is set to HBL1, and a low limit bias magnetic field in which the magnetic bubble circle the minor loop mR is to HBL2, the magnetic bubble in which writing is executed is permitted to circle in the minor loop mR in bias magnetic fields HBL1-HBL2. Thus, the failed loop which exists near the low limit of the integrated operation area due to a defect existing in the pattern of the minor loop mR and a pattern generation substrate can be detected in a short time.