
Exercises
635
Although the basic algorithm is radix 2, it has been extended to higher
radices. The most-direct extension is to radix 4, which results in half the number
of iterations as for radix 2. However, in the high-radix cases, the scaling factor
is not constant, so additional hardware is required to compute the scaling factor.
Consequently, an alternative approach is to perform the first iterations radix 2
and the last iterations radix 4, since the scaling factor is affected only by the first
iterations.
Very-high-radix implementations have been proposed using selection by
rounding (see the references at the end of the