DETECTION METHOD FOR BUBBLE VORTEX FOR BUBBLE MEMORY CHIP

摘要

PURPOSE:To reduce the test time and to increase the reliability, by setting the bias magnetic field to a given value after erasing all the bubbles among bubble chips and performing read-out operation in synchronizing with the period of driving magnetic field. CONSTITUTION:The operation margin performance A at the driving magnetic field HR versus bias magnetic field HB of the major loop 1 on the bubble chip memory is obtained, the applied magnetic field is set to the point B on the curve A, and all the bubbles on the chip are erased by increasing HB to the point C during the time a. After that, HB is returned to the lower limit D (point B) and the read-out for all bits is made. In this case, driving magnetic field is produced with the driving current a, driving current b flows to the transfer gate 7 to obtain the output signal c from the detector 3. Thus, all the bit information of the minor loop 2 is transferred every one period of HB on the loop 1 by opening the gate 7 to enable to detect the signal c as the vortex bubble.