skip to main content
article
Free Access

A case study in using two-level control stores

Published:01 September 1988Publication History
Skip Abstract Section

Abstract

A two-level control store can reduce storage requirements of microprograms without affecting microprogrammability, which is important for a processor programmed directly in microcode. This paper presents a case study investigating how to use a two-level control store effectively. The study is based on Warp cell, a high-performance, microprogrammable processor used in a systolic array computer called Warp. Warp cell is programmed directly in microcode by an optimizing compiler and uses wide horizontal microinstructions with over 200 bits.Two methods which can increase the effectiveness of using a two-level control store have been considered. First, control store configuration can be adjusted so that the storage of an instruction can be partitioned among microstore and one or more nanostores to maximize storage efficiency. Second, it is possible to increase storage reduction of microprograms by exploiting insignificant and symmetric fields in instructions in mapping microprograms to the control store. It has been found that the average storage reduction for Warp cell programs can be increased from 41% in a straightforward two-level control store implementation to 72% by using these methods.

References

  1. Agerwala, T. "Microprogram Optimization: A Survey". IEEE Transactions on Computers C-25, 10 (Oct. 1976), 962--973.Google ScholarGoogle ScholarDigital LibraryDigital Library
  2. Annaratone, M., Amould, E., Gross, T., Kung, H.T., Lam, M., Menzilcioglu, O., Sarocky, K. and Webb, J.A. Warp Architecture and Implementation. Conference Proceedings of the 13th Annual International Symposium on Computer Architecture, June, 1986, pp. 346--356. Google ScholarGoogle ScholarDigital LibraryDigital Library
  3. Annaratone, M., Bitz, F., Deutch, J., Hamey, L., Kung, H. T., Maulik, P., Ribas, H., Tseng, P. and Webb, J. Applications Experience on Warp. Proceedings of the 1987 National Computer Conference, AFIPS, 1987.Google ScholarGoogle Scholar
  4. Annaratone, M, Arnould, E., Cohn, R., Gross, T., Kung, H.T., Lam, M., Menzilcioglu, O., Sarocky, K., Senko, J., and Webb, J. Warp Architecture: From Prototype to Production. Proceedings of the 1987 National Computer Conference, AFIPS, 1987.Google ScholarGoogle Scholar
  5. Baer, J.L. and Koyama, B. "On the Minimization of the Width of the Control Memory of Microprogrammed Processors". IEEE Transactions on Computers C-28, 4 (Apr. 1979), 310--316.Google ScholarGoogle ScholarDigital LibraryDigital Library
  6. Grasselli, A. "The Design of Program-Modifiable Micro-Programmed Control Units". IRE Transactions on Electronic Computers EC-11, 6 (June 1962), 334--339.Google ScholarGoogle Scholar
  7. Gross, T. and Lam, M. Compilation for a High-performance Systolic Array. Proceedings of the SIGPLAN 86 Symposium on Compiler Construction. ACM SIGPLAN, June, 1986, pp. 27--38. Google ScholarGoogle ScholarDigital LibraryDigital Library
  8. Lam, M. A Systolic Array Optimizing Compiler. Ph.D. Th., Carnegie Mellon University, May 1987. Google ScholarGoogle ScholarDigital LibraryDigital Library
  9. Martinez-Carballido, J. F. and Powers, V. M. General Microprogram Width Reduction Using Generator Sets. Proceedings of the 14th Annual Workshop on Microprogramming, October, 1981, pp. 144--153. Google ScholarGoogle ScholarDigital LibraryDigital Library
  10. Tudruj, M. S. A Customized Control Store Design in Microprogrammed Control Units. Proceedings of the 18th Annual Workshop on Microprogramming, December, 1985, pp. 189--199. Google ScholarGoogle ScholarDigital LibraryDigital Library

Index Terms

  1. A case study in using two-level control stores

    Recommendations

    Comments

    Login options

    Check if you have access through your login credentials or your institution to get full access on this article.

    Sign in

    Full Access

    • Published in

      cover image ACM SIGMICRO Newsletter
      ACM SIGMICRO Newsletter  Volume 19, Issue 3
      Sept. 1988
      58 pages
      ISSN:1050-916X
      DOI:10.1145/62185
      Issue’s Table of Contents

      Copyright © 1988 Author

      Publisher

      Association for Computing Machinery

      New York, NY, United States

      Publication History

      • Published: 1 September 1988

      Check for updates

      Qualifiers

      • article

    PDF Format

    View or Download as a PDF file.

    PDF

    eReader

    View online with eReader.

    eReader
    About Cookies On This Site

    We use cookies to ensure that we give you the best experience on our website.

    Learn more

    Got it!