Debugging HW/SW interface for MPSoC: video encoder system design case study

ABSTRACT

This paper reports a case study of multiprocessor SoC (MPSoC) design of a complex video encoder, namely OpenDivX. OpenDivX is a popular version of MPEG4. It requires massive computation resources and deals with complex data structures to represent video streams. In this study, the initial specification is given in sequential C code that had to be parallelized to be executed on four different processors. High level programming model, namely Message Passing Interface (MPI) was used to enable inter-task communication among parallelized C code. A four processor hardware prototyping platform was used to debug the parallelized software before final SoC hardware is ready. The targeting of abstract parallel code using MPI to the multiprocessor architecture required the design of an additional hardware-dependent software layer to refine the abstract programming model. The design was made by a team work of three types of designer: application software, hardware-dependent software and hardware platform designers. The collaboration was necessary to master the whole flow from the specification to the platform.The study showed that HW/SW interface debug was the most time-consuming step. This is identified as a potential killer for application-specific MPSoC design. To further investigate the ways to accelerate the HW/SW interface debug, we analyzed bugs found in the case study and the available debug environments. Finally, we address a debug strategy that exploits efficiently existing debug environments to reduce the time for HW/SW interface debug.

REFERENCES

• 1: The Ptolemy project, http://ptolemy.eecs.berkeley.edu/
• 2: E. Rijpkema , K. G. W. Goossens , A. Radulescu , J. Dielissen , J. van Meerbergen , P. Wielage , E. Waterlander, Trade Offs in the Design of a Router with Both Guaranteed and Best-Effort Services for Networks on Chip, Proceedings of the conference on Design, Automation and Test in Europe, p.10350, March 03-07, 2003
• 3: Jinfeng Liu , Pai H. Chou, Energy Optimization of Distributed Embedded Processors by Combined Data Compression and Functional Partitioning, Proceedings of the 2003 IEEE/ACM international conference on Computer-aided design, p.201, November 09-13, 2003 [doi>10.1109/ICCAD.2003.62]
• 4: Paul Lieverse , Pieter Van Der Wolf , Kees Vissers , Ed Deprettere, A Methodology for Architecture Exploration of Heterogeneous Signal Processing Systems, Journal of VLSI Signal Processing Systems, v.29 n.3, p.197-207, November 2001 [doi>10.1023/A:1012231429554]
• 5: W. Cesário , A. Baghdadi , L. Gauthier , D. Lyonnard , G. Nicolescu , Y. Paviot , S. Yoo , A. A. Jerraya , M. Diaz-Nava, Component-based design approach for multicore SoCs, Proceedings of the 39th conference on Design automation, June 10-14, 2002, New Orleans, Louisiana, USA [doi>10.1145/513918.514115]
• 6: J.-Y. Brunel , W. M. Kruijtzer , H. J. H. N. Kenter , F. Pétrot , L. Pasquier , E. A. de Kock , W. J. M. Smits, COSY communication IP's, Proceedings of the 37th conference on Design automation, p.406-409, June 05-09, 2000, Los Angeles, California, United States [doi>10.1145/337292.337515]
• 7: Henry Chang , Larry Cooke , Merrill Hunt , Grant Martin , Andrew J. McNelly , Lee Todd, Surviving the SOC revolution: a guide to platform-based design, Kluwer Academic Publishers, Norwell, MA, 1999
• 8: Christian Berthet, Going mobile: the next horizon for multi-million gate designs in the semi-conductor industry, Proceedings of the 39th conference on Design automation, June 10-14, 2002, New Orleans, Louisiana, USA [doi>10.1145/513918.514015]
• 9: OpenDivX, Project Mayo, http://www.projectmayo.com
• 10: The Message Passing Interface (MPI) standard, http://www-unix.mcs.anl.gov/mpi/
• 11: ARM AP Integrator, http://www.arm.com
• 12: OpenMP, http://www.openmp.org/
• 13: SystemC, http://www.systemc.org
• 14: CoCentric System Studio, http://www.synopsys.com/
• 15: ConvergenSC, http://www.coware.com
• 16: Platform Express, http://www.mentor.com
• 17: Virtex-II Pro FPGAS, http://www.xilinx.com

INDEX TERMS

Primary Classification:
  B. Hardware
  B.1 CONTROL STRUCTURES AND MICROPROGRAMMING

Additional Classification:
  D. Software
  D.1 PROGRAMMING TECHNIQUES
      D.1.3 Concurrent Programming
  D.2 SOFTWARE ENGINEERING
      D.2.5 Testing and Debugging

General Terms:
Design, Experimentation, Verification

Keywords:
debug, hardware-dependant software, hardware-software interface, multiprocessor system-on-chip