CARRY OUTPUT CIRCUIT FOR BINARY NUMBER ADDITION AND BINARY NUMBER ADDITION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a carry output circuit suppressing delay time without complicating the circuit even when the number of input digits increases. ;SOLUTION: The carry output circuit is provided with a low-order digit carry part 151 computing the low-order digit values of respective numerical values A and B and outputting low-order carry signals, a pertinent digit all 1 detection part 152 detecting that the respective OR output values of the pertinent addition digits of the respective numerical values A and B are all 1, a pertinent digit AND output part 44a outputting a first temporary pertinent carry signal to the arithmetic part of highorder digits when input is present from both of the low-order digit carry part 151 and the pertinent digit all 1 detection part 152, a pertinent digit carry part 153 computing the respective values of the pertinent addition digits of the respective numerical values A and B and outputting a second temporary pertinent carry signal to the arithmetic part of the high-order digits and a pertinent digit OR output part 44b outputting pertinent carry signals to the arithmetic part of the high-order digits when at least one of the first temporary pertinent carry signal from the pertinent digit AND output part 44a and the second temporary pertinent carry signal from the pertinent digit carry part 153 is inputted.;COPYRIGHT: (C)2003,JPO