Magnetic bubble memory chip with dedicated redundancy data section

Abstract

A magnetic bubble memory chip structure on which a plurality of magnetic bubble storage loops are provided for containing information data as represented by bubbles and voids and including a dedicated area on the chip for containing redundancy data as represented by a chain of bubbles and voids arranged in a predetermined manner to identify good and defective information data storage loops. The redundancy data-containing dedicated area of the chip comprises a plurality of redundancy data-containing storage loops of equal number to the information data-containing storage loops so as to correspond thereto in a one-on-one relationship, with the number of individual bit positions included in each information data-containing storage loop being significantly greater than the number of bit positions included in each individual redundancy data-containing storage loop. At least one bubble detector is included on the chip, being associated with the information data-containing bubble storage loops and the redundancy data-containing storage loops for receiving readout of information data and redundancy data in an alternating coordinated sequence with each bit of information data from a respective information data-containing storage loop being preceded by a bit of redundancy data from the corresponding redundancy data-containing storage loop which identifies whether the following bit of information data is from a good or a defective information data-containing storage loop. The output from the detector is operably controlled by appropriate logic circuitry for restricting the usable readout from the information data-containing bubble storage loops to data which is delivered from good storage loops as determined by the redundancy data imparted by respective redundancy data-containing storage loops.