GB1248716A - Associative storage systems - Google Patents

Abstract

1,248,716. Associative stores. INTERNATIONAL BUSINESS MACHINES CORP. 16 June, 1970, No. 29113/70. Heading G4C. An associative data storage system comprises two storage arrays interconnected such that one or more selected words from either one of the arrays can be applied to the other array as a search argument for accessing the other array. In a first embodiment with only two arrays as above, each storage cell is a 4-state cell (0, 1, " match anything ", " mismatch anything ") as in Specification 1,127,270 (referred to). Corresponding bit line pairs of the two arrays are connected through logic driver circuits which permit either array to be written into or interrogated using data read from the other array or inserted from outside, or either array to be read out to the other array or to outside. A second embodiment differs in having a matrix of arrays, corresponding bit line pairs being connected going down each column of this matrix and corresponding word/mismatch lines being connected going along each row. Logic circuits interconnecting adjacent arrays in the matrix are controlled by two pairs of control lines per row of arrays in the matrix. A ring counter reads out columns of auxiliary 4-state cells a column at a time, to at least partially control a column of latch circuits, some of which control a pair of the control lines (see above) each, and the rest of which each control and are partially controlled by a respective word/mismatch line from the matrix of arrays and control for read out a respective row of further auxiliary cells. Correspondingly positioned cells in these latter rows are connected by their bit lines in columns, each column causing the ring counter to skip a respective position or not according to the value read out.