Two methods for fast integer binary-BCD conversion

Two methods for performing binary-BCD conversion of positive integers are discussed. The principle which underlies both methods in the repeated division by five and then by two, obtained the first by means of substructions performed from left to right, the second by shifting bits before next subtraction. It is shown that these methods work in a time which is linear with the length in bit of the number to be converted. A ROM solution is proposed and its complexity is compared with that of other methods.