N-digit subtraction unit, N-digit subtraction module, N-digit addition unit and N-digit addition module

摘要

Provided are N-digit addition and subtraction units and N-digit addition and subtraction modules in which borrowing and carrying are not propagated in modules having basic digits. In the units and modules, an output pattern of results of addition and subtraction is predicted based on a relation between an augend and an addend and a relation between a minuend and a subtrahend, respectively, thereby preventing borrowing and carrying from being propagated in modules having basic digits.