Other Functions of the Arithmetic Unit

The arithmetic unit of a computer may be called on to execute many different functions besides those discussed so far. These include logical operations, in which the result is a word, the bits of which are a logical combination of the corresponding bits of the operands. Among these are shift functions, in which the bits of a word are reordered in a specified fashion. Usually the bits remain in the same order, but changed in position; the end bits may be lost, or re-entered at the opposite end of the word. These instructions are straightforward and will not be discussed in detail here.