Magnetic domain minor loop redundancy system

A magnetic domain memory system comprising:

• a thin magnetic film suitable for use in generating magnetic domains;
• means disposed on said magnetic film for defining a major path for propagating magnetic domains;
• and
• a plurality of minor magnetic domain propagation loops adjacent said path, one or more of said minor loops being inoperable, means for transferring magnetic domains between said minor loops and said major path;
• and
• a programmable read-only memory for storing the locations of said one or more inoperable loops, said programmable read-only memory providing output signals effective to inhibit transfer of magnetic domains into or out of said one or more inoperable loops.

A magnetic domain memory system including:

• a plurality of magnetic domain data chips each having a major magnetic domain propagation path means and a plurality of minor loops for propagating magnetic domains, at least one of said minor loops being inoperative for propagating magnetic domains;
• control means for propagating magnetic domains around each of said major path means and around said loops at a selected clock frequency and controlling transfer of data in the form of magnetic domains between said minor loops and said major path means;
• a programmable read-only memory connected to said control means for storing the relative location of each defective minor loop on each of said data chips, the output of each address of said programmable read-only memory providing a binary code corresponding to the time delay between defective minor loops;
• and
• counter means coupled to the output of said programmable read-only memory, said counter means providing an output pulse, said output pulse being coupled to said control means for inhibiting any read or write operations during the time interval associated with said output pulse, said counter means providing said output pulse responsive to the output of said programmable read-only memory, said output pulse being delayed in time from application of said programmable read-only memory output by a time corresponding to the binary code present at the programmable read-only memory output.

A magnetic domain memory system including:

• a plurality of magnetic domain memory modules, each module respectively including a plurality of magnetic domain chips;
• control means associated with each of said chips for propagating magnetic domains, said control means including sensors for detecting the presence or absence of magnetic domains and generators for writing in new magnetic domains, each of said chips including a major magnetic domain propagation path and a plurality of minor loop propagation paths associated therewith, one or more of said minor loops of at least one chip being defective;
• a programmable read-only memory coupled to said plurality of memory modules and said control means, said programmable read-only memory storing the location of the defective minor loops in each chip;
• first storage means coupled to said plurality of modules for transferring data in parallel between said plurality of modules and said first storage means;
• second storage means coupled to an output terminal for transferring data in parallel between said output terminal and said second storage means;
• said first and second storage means coupled together by serial data transfer means, said first and second storage means further coupled to the output of said programmable read only memory whereby serial data transfer between said first and second storage means is prevented during transfer times corresponding to the location of a defective minor loop.