PURPOSE: To make it possible to decide securely the existence of a new-creative defective loop, by increasing the intensity of a revolving magnetic field much greater than that of the least upper bound magnetic field in memory-operation securing range for an extremely short period.
CONSTITUTION: A magnetic bubble memory chip is equipped with minor loop (m), read major line RML, write major line WML, magnetic bubble detector D, magnetic bubble generator G, replicate gate R, swap gate T, and guard rail GR. To decide the existence of a defective loop, bias magnetic field intensity HB is increased about 50% to clear bubbles and revolving magnetic field intensity HR is increased above the maximum value of value H1 under normal use condition. At the same time, a frequency in revolution is lowered. Then, the revolving magnetic field intensity and revolution frequency are returned under the normal use conditions to read information in all addresses of all minor loops, so that a loop out of which a bubble is read out will be considered to be defective.
HARA KOUZOU
FUSATANI AKIHIKO
| JPS51139737A | 1976-12-02 | |||
| JPS51126733A | 1976-11-05 |