US 11,942,152 B2
Fuzzy string search circuit
Yoshinori Okajima, Tokyo (JP); and Mariko Okajima, Tokyo (JP)
Assigned to Yoshinori Okajima, Tokyo (JP)
Filed by Yoshinori Okajima, Tokyo (JP)
Filed on Oct. 3, 2022, as Appl. No. 17/958,898.
Application 17/958,898 is a continuation of application No. PCT/JP2020/015100, filed on Apr. 1, 2020.
Prior Publication US 2023/0073272 A1, Mar. 9, 2023
Int. Cl. G11C 15/04 (2006.01); G11C 7/10 (2006.01); G11C 7/22 (2006.01)
CPC G11C 15/04 (2013.01) [G11C 7/1063 (2013.01); G11C 7/1069 (2013.01); G11C 7/22 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An approximate search circuit comprising:
a plurality of matching degree determination circuits, wherein each of the matching degree determination circuits includes,
a first storage circuit including a plurality of memory cells arranged in a matrix with at least m columns by k rows, where m is an integer of two or greater and k is an integer of two or greater,
m or m pairs of activation signal input lines for carrying pulse signals from the outside to the memory cells,
k detection lines that conduct the signals from the memory cells to a following counting circuit, when any of the memory cells generates current as a signal,
the counting circuit that has a plurality of multiplying circuits each of which makes a product operation of the number of signals that conducted through the detection line by a predetermined weight coefficient for the detection line, and an adding-up circuit of accumulating the results of all the product operations in the counting circuit,
a second storage circuit that stores therein a threshold value for use in evaluating an output of the counting circuit, and
a determination circuit that evaluates the output of the counting circuit by comparing with the threshold value, wherein
when the determination circuit in a predetermined time period receives the output of the counting circuit which indicate the output of the counting circuit exceeded the threshold value, the determination circuit puts out an ignition signal as an output of the matching degree determination circuit,
each of the matching degree determination circuits shares the activation signal input lines commonly as their input connections, and
the approximate search circuit puts out,
information indicating which of the matching degree determination circuits has exceeded the threshold value stored in the second storage circuit, or
information indicating which of the matching degree determination circuits has most similar data to data delivered by the signals sent through the activation signal input lines.