Patent ID: 7221291

Claim:
A character string retrieving circuit for retrieving a character matched with a character of an inputted character string at every one period of an operation clock from a dictionary, creating a match/no match signal indicating whether or not a character matched with a retrieval target exists in a dictionary and incrementing the number of characters of the retrieval target one by one by using the retrieved result in the next clock period if the character matched with the retrieval target exists in the dictionary, comprising: delay means for delaying said match/no match signal by n periods (n is an integer greater than 1) of said operation clock; creating means for creating in advance signals of 2 n kinds consisting of combinations of assumption to assume that a character matched with a retrieval target exists in said dictionary and assumption to assume that a character matched with a retrieval target does not exist in said dictionary in each period from the n−1 period before the clock period to the clock period as signals to predict retrieved results in a certain clock period; and selecting means for selecting a signal with a correct assumption from said signals of 2 n kinds created by said creating means in accordance with said match/no match signal delayed by said delay means, wherein the signal selected by said selecting means is used in the next clock period.