
532 c H ApT E R 9 Digit-Serial Arithmetic
Without attempting any optimizations, several filter implementation alternatives
are analyzed, assuming (i) parallel-in/parallel-out interface, (iii) coefficients in
parallel form, and (iii) fixed-point format with n bits. Alternatives 2 and 3 use
digit-serial arithmetic internally.
1. Conventional parallel arithmetic implementation may, for example, use
a five-module network: Module M1 is a n • n/2 multiplier producing
a carry-save product; module M2 is a multiply-add unit producing the
2n-bit product in carry-save form; modules M3 and M4 are [4:2] adders;
and module M5 is a carry-propagate ...