17.
    发明专利
    未知

    公开(公告)号:DE2209253A1

    公开(公告)日:1973-09-06

    申请号:DE2209253

    申请日:1972-02-26

    Abstract: 1365057 Testing data stores INTERNATIONAL BUSINESS MACHINES CORP 24 Jan 1973 [26 Feb 1972] 3608/73 Heading G4C The addressing circuits of an addressable data store are tested by sequentially addressing the storage locations, writing into each addressed location at least a part of its address, again sequentially addressing the storage locations, and comparing each applied address signal or part thereof with data read from that location, and generating an output AS only when the result of the comparison changes from match to mismatch or vice versa. As described, the output from the comparator is fed to a control circuit 5 which reverses the comparison criterion each time the comparator output changes to produce a signal AS which enables gate 6 thereby to record the current address at 4. The resulting recorded addresses delineate fields in the store in which the addresses do not match the stored data. Circuit 5, Fig. 2, includes two AND gates 57 and 55 enabled by a clock signal T1, the output of a latch 51 which stores the comparator output when clocked by T2 which follows T1, and the true and negated comparator outputs.

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