ACORN: a local customization approach to DCVS physical design

ABSTRACT

Differential cascode voltage switch (DCVS) trees are high performance, high functionality CMOS circuits, which, because they have a large number of inputs and internal connections, are difficult to wire on a large scale. Wirability is substantially improved by local customization at the tree level. This paper describes a DCVS customization procedure that exploits the fact that a Boolean function has more than one physical realization. Using ACORN, an automated physical design system based on this concept, we have placed and wired several designs, the largest of which is a group of three interconnected macros comprising approximately 800 DCVS trees.

REFERENCES

• 1: L. G. Heller, W. R. Griffin, J. W. Davis and N. G. Thoma, "Cascode 'Voltage Switch Logic: A Differential CMOS Logic Family," 31st IEEE International Solid- State Circuits Conference, Digest of Technical Papers, 1984, pp. 16-17.
• 2: C. K. Erdelyi, W. P. Griffin and R. D. Kilmoyer, "Cascode Voltage Switch Logic Design," VLSI Design, vol. V, 1984, pp. 78-86.
• 3: R. K. Brayton, C. L. Chen, C. T. McMullen, R. H. J. M. Otten and Y. J. Yamour, "Automated implementation of Switching Functions as Dynamic CMOS Circuits," Proceedings of the IEEE Custom Integrated Circuits Conference, 1984.
• 4: Peter S. Hauge , Ellen J. Yoffa, ACORN: a system for CVS macro design by tree placement and tree customization, IBM Journal of Research and Development, v.28 n.5, p.596-602, September 1984
• 5: R. K. Brayton and C. T. McMullen, "The Decomposition and Factorization of Boolean Expressions," Proceedings of the International Symposium on Circuits and Systems, Rome, 1982, pp. 49-54.
• 6: T. Uehara and W. M. vanCleemput, "Optimal Layout of CMOS Functional Arrays," I}EEE Transactions on Computers, vol. C-30, 1981, pp. 2,05-312.
• 7: Peter C. Elmendorf, KWIRE: a multiple-technology, user-reconfigurable wiring tool for VLSI, IBM Journal of Research and Development, v.28 n.5, p.603-612, September 1984
• 8: M. D. F. Schlag, E. J. Yoffa, P. S. Hauge, and C. K. Wong, "A Method for Improving Cascode-Switch Macro Wirability," IEEE Trans. CAD-IC, vol. 4, 1985, pp. 150-155.

INDEX TERMS

Primary Classification:
  B. Hardware
  B.7 INTEGRATED CIRCUITS
      B.7.1 Types and Design Styles
          Subjects: VLSI (very large scale integration)

Additional Classification:
  J. Computer Applications

General Terms:
Design, Experimentation, Measurement, Performance, Theory