VLSI Digital Signal Processing Systems: Design and Implementation

6.6    CONCLUSIONS

Folding is a systematic transformation technique for design of time-multiplexed architectures and is a generalization of the techniques in [10],[11]. Although folded circuits require less silicon area, these can be operated at higher speed by exploiting fine-grain pipelining of the functional units. This results in no net loss in the sample rate of the system for small folding factors. Folding sets can be designed by any scheduling and allocation techniques (see Appendix B). Lifetime analysis, a technique used in compiler theory, can be used to reduce the number of storage units in folded circuits. This chapter has concentrated on storage unit reduction for scalars or one-dimensional variables. Register minimization for systems involving vectors or multidimensional signals is beyond the scope of this book (see [12],[13]). Extension of folding to one-dimensional multirate systems has been addressed. For folding of multi-dimensional single-rate and multirate systems, the reader is referred to [14].