Memory management

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Memory management

• Ingrid Verbauwhede
• Department of Electrical Engineering
• University of California Los Angeles

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Literature

1. F. Catthoor, K. Danckaert, S. Wuytack, N. Dutt,
   Code transformations for Data Transfer and
   Storage Exploration Preprocessing in Multimedia
   Processors, IEEE Design Test of Computers,
   May-June 2001, pg. 70-82.
2. P. Panda, F. Catthoor, N. Dutt, et al, Data and
   memory optimization techniques for embedded
   systems, ACM Transactions on Design Automation
   of Electronic Systems, Vol. 6, no. 2, april 2001,
   pg. 149- 206.
3. W. Verhaegh, E. Aarts, P. van Gorp, P. Lippens,
   A Two-Stage approach to multi dimensional
   periodic scheduling, IEEE Transactions on CAD,
   Vol. 20, no. 10, October 2001, pg. 1185-1199.

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Important Memory Decisions inEmbedded Systems

• What is a good memory architecture for an
  application?
• Total memory requirement
• Delay due to memory
• Power dissipation due to memory access
• Compiler and Synthesis tool (Exploration tools)
  should make informed decisions on
• Registers and Register files
• Cache parameters
• Number and size of memory banks

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Minimizing Register Count

• Graph Colouring is NP-complete
• Heuristics (Growing clusters)
• Polynomial time solution exists for straight
  line code (no branches)
• Left-edge algorithm
• Possible to incorporate other factors
• Interconnect cost annotated as edge-weight

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Intermediate conclusion

• Memory management is important
• Two main types
• background memory optimization
  (multidimensional arrays)
• foreground memory optimization (scalars)
• Foreground memory
• registers graph coloring
• register files and limited access
• model of individual read/write operations to SRAM