Highly parallel structure for fast multi cycle binary and decimal adder unit

摘要

An adder circuit for adding two binary or two decimal operands A and B in which the carries are calculated directly from the input operands A and B without including the plus 6 or minus 6 operations into the carry calculation. For all timing critical functions the reduced input data set, i.e., valid decimal data can be used and the non-existing decimal numbers (10 to 15) need not be excluded by separate check logic any more. This reduces the complexity of the logic functions.