Title :
An Interconnect-Centric Approach to Cyclic Shifter Design Using Fanout Splitting and Cell Order Optimization
Author :
Zhu, Haikun ; Zhu, Yi ; Cheng, Chung-Kuan ; Harris, David M.
Author_Institution :
Dept. of CSE, California Univ., La Jolla, CA
Abstract :
We propose two orthogonal approaches to logarithmic cyclic shifter design. The first method, called fanout splitting, replaces multiplexers in a conventional design with demultiplexers which have two fanouts driving the shifting and non-shifting paths separately. The use of demultiplexers has a two-fold effect; it cuts the accumulated wire load on the critical path from O(Nlog2(N)) to O(N), and reduces the switching probabilities on the inter-stage long wires from 1/4 to 3/16. We then perform cell order optimization to further improve the delay, and formulate it as an integer linear programming problem. For the 64-bit case, the two approaches together reduce the total delay by 67.1% and dynamic power consumption by 17.6%, respectively.
Keywords :
circuit optimisation; integer programming; integrated circuit interconnections; linear programming; logic circuits; logic design; 64 bit; accumulated wire load; cell order optimization; demultiplexers; fanout splitting; integer linear programming; interconnect-centric approach; logarithmic cyclic shifter design; nonshifting paths; shifting path; switching probabilities; Adders; Capacitance; Delay; Design optimization; Energy consumption; Integer linear programming; Integrated circuit interconnections; Multiplexing; Multivalued logic; Wire; Design; Performance; Power; cyclic shifter; fanout splitting; integer linear programming; interconnect; permutation;
Conference_Titel :
Design Automation Conference, 2007. ASP-DAC '07. Asia and South Pacific
Conference_Location :
Yokohama
Print_ISBN :
1-4244-0629-3
Electronic_ISBN :
1-4244-0630-7
DOI :
10.1109/ASPDAC.2007.358054