METHOD AND DEVICE FOR ADDING PARTIAL PRODUCT, METHOD AND DEVICE FOR MULTIPLYING FLOATING POINT, AND METHOD AND DEVICE FOR FLOATING POINT PRODUCT-SUM OPERATION

摘要

PROBLEM TO BE SOLVED: To unnecessitate the code extension of a negative partial product. SOLUTION: A booth decoder 101 executes quadratic booth decoding of a multiplier and a booth selector 102 generates a partial product except high- order two digits from the output of the decoder and a multiplicand. A partial product correcting circuit 104 outputs a high-order two digits obtained by correcting the high-order two digits based on the multiplier (three digits per each partial product) and the multiplicand (a digit next to a silent one digit). A carry storage adder 105 adds outputs 113 to 115 without code extension.