A bidirectional loop-to-loop transfer gate for ion-implanted bubble devices with on chip cache organization

A new bidirectional loop-to-loop transfer gate has been designed with an N-shape conductor stripe. It is characterized for use with ion-implanted bubble devices with on chip cache organization (OCCO). The gate is operated in 4 modes for He+ ion implanted devices with 1 µm diameter bubbles. Only one of the 4 transfer modes is found to be usable for bidirectional transfer operation, according to bubble data recurrence considerations between cache and storage loops, and according to operation margin stability. Composite operation margins are obtained as 25 Oe for greater than 55 Oe in-plane drive field, even for consecutive data transfer. The bidirectional transfer gate makes possible ion-implanted bubble devices for high access performance, even in high bit density large capacity memories.