LEADING ZERO PREDICTION CIRCUIT AND CONTROL METHOD FOR LEADING ZERO PREDICTION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To reduce a circuit size of a leading zero prediction circuit that predicts a head bit position where a first logical value appears in a bit string after an operation of a data pair.;SOLUTION: A first predicted value after an operation of each bit pair of a data pair and a second predicted value after an operation of an end bit pair are generated. Each first encoder generates first positional information indicating a head bit position from a predetermined number of first predicted values and appearance information of a first logical value, and a second encoder generates second positional information indicating a head bit position from the second predicted value and the predetermined number of first predicted values. A positional information generation unit generates, based on the appearance information and the first positional information, third positional information indicating the head bit position. A replacement unit outputs, when the end bit pair is an end of the data pair, the second positional information to the positional information generation unit instead of the first positional information, and a mask unit changes appearance information outputted by the first encoder corresponding to the end bit pair to information indicating the appearance of the first logical value.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2018,JPO&INPIT