Page buffer counting for in-memory search

Abstract

A memory such as a 3D NAND array, having a page buffer having page buffer cells coupled to bit lines has a search word input such as a search word buffer coupled to word lines. A circuit, such as string select gates, is provided to connect a selected set of memory cells in the array to the page buffer. The page buffer includes sensing circuitry configured to apply a match sense signal to a latch in a plurality of storage elements for a stored data word and an input search word. Logic circuitry uses storage elements in the plurality of storage elements of the page buffer to accumulate the match sense signals output by the sensing circuitry over a sequence matching a plurality stored data words to one or more input search words. A match for a search is based on a threshold and the accumulated match sense signals.