Reballoting 1076.1

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Reballoting 1076.1

• FDL'03, 9/24/2003
• Ernst Christen

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Reasons for Reballoting

• IEEE Std. 1076.1-1999 was approved in 1999
• IEEE Standards must be reaffirmed every 5 years

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Necessary Updates to IEEE Std. 1076.1-1999

• Synchronization with IEEE Std. 1076-2002
• Correction of errata
• 8 page errata sheet, published at eda.org/analog
• Definitional errors (including examples)
• Typographical errors
• Layout issues
• Several more errata

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Enhancements to Consider

• Postponed requirements
• Handling of mixed nets
• Support for "analog" and "digital" architecture
  for an entity
• Problem is that ports of entity are unchangeable

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Mixed Nets

• A net where participating objects are of
  different object classes
• signal
• quantity
• terminal
• Compare with VHDL net where all participating
  objects are signals
• Types may be different

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Handling of Mixed Nets

• Insert conversion model between disparate objects
• Conversion model defines semantics of mixed
  connection
• Can be arbitrarily complex and include, in
  addition to value "translation", loading effects,
  power supply dependency, etc.
• Note that signal ports and quantity ports are
  directional, but terminal ports are not

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Mixed Nets Local Focus

• Define semantics of a port association element
  whose formal and actual are of different object
  class
• Advantage
• Could follow type conversion/conversion function
  paradigm
• Disadvantage
• Information loss if association elements at
  different levels of hierarchy are involved

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Mixed Nets Global Focus

• If mixed net includes a terminal, convert net to
  a node, otherwise convert net to a quantity net
• Insert conversion models between the net and the
  objects connected to the net that have a
  different object class
• Advantage
• Best approach possible
• Disadvantage
• Multiphase elaboration
• Definitional difficulties with conversion fcts

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Mixed Nets Global Focus Example
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Mixed Nets Global Focus Example
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conversion models
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Mixed Nets Global Focus Example
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