Patent attributes
In an associative memory, when a reference data having the minimum distance with respect to an input data is detected as winner, it is determined whether or not a distance between the input data and winner is less than a threshold value. If the distance is less than the threshold value, it is determined that the reference data detected as winner matches with the input data, and then, a rank of the reference data is improved. If the distance is more than the threshold value, it is determined that the reference data is data different from the input data, and then, the input data is written as new reference data to the associative memory and replaces the reference data with the lowest rank. The upper positions of rank form as a long-term memory, and the lower positions thereof form as a short-term memory.