IBM Journal of Research and Development
IBM Skip to main content
  Home     Products & services     Support & downloads     My account  

  Select a country  
Journals Home  
  Systems Journal  
Journal of Research
and Development
    Current Issue  
    Recent Issues  
    Papers in Progress  
    Search/Index  
    Orders  
    Description  
    Patents  
    Recent publications  
    Author's Guide  
  Staff  
  Contact Us  
  Related links:  
     IBM Research  

IBM Journal of Research and Development  
Volume 28, Number 5, Page 596 (1984)
Design Automation
  Full article: arrowPDF   arrowCopyright info





   

ACORN: A system for CVS macro design by tree placement and tree customization

by P. S. Hauge, E. J. Yoffa
ACORN is a system for the physical design of cascode voltage switch (CVS) macros which utilizes tree placement and tree customization to improve macro wirability. The results obtained by designing a 43-tree differential (DCVS) macro on a masterslice chip image are presented to illustrate the design improvements. In this example, tree placement reduces wire length and via count by 12 percent relative to a transistor-pair placement design. Tree customization increases this improvement to 25 percent, and increases the porosity of the wired macro to vertical global wires from 8 percent for tree placement alone to 15 percent.
Related Subjects: Design automation; Integrated circuits; Logic macros; LSI