IBIS 5'0 Pending Changes

1
IBIS 5.0Pending Changes

• IBIS 5.0 has several BIRDs already queued
• BIRD74.6 EMI Parameters
• BIRD95.6 Power Integrity Analysis using IBIS
• BIRD97.2/98 Gate Modulation Effect
• BIRD103.1 Model Spec DDR2 Over/Undershoot
• BIRD1xx External Model under Circuit Call
• BIRD1xx ICM-IBIS Linking
• BIRD1xx User-Defined Measurements

2
IBIS 5.0 Direction

• IBIS 5.0 is a fork in the road
• With each revision, we add keywords,
  subparameters
• Features from previous versions unchanged
• Clarifications excepted
• IBIS 5.0 becoming highly encumbered
• 101 keywords in IBIS 4.2
• New features have to avoid stepping on old ones
• Example ICM-IBIS link nearly impossible due to
  paths blocked by old requirements, assumptions

3
Proposed Actions

• New compatibility switch
• If switch is in non-compatible mode, rules
  regarding previous versions are simplified
• Compatible mode keeps 4.2 rules features plus
  enhancements we selectively add

Splitting IBIS 5.0 into sub-specifications
New keyword, feature development need not
be hampered by previous version limitations
Old features can be maintained as they are phased
out
4
Non-Compatible Mode

• New mode eliminates keywords
• Package, TTgnd, TTpower
• Voltage Range, Driver Schedule, Submodel
• PKG, EBD, Diff Pin, Pin Mapping, etc.
• Simplify features using multi-lingual structure
• Pin no longer assumes 11 link to Model
• Can add Pad keyword for buffer pad nodes
• Support arbitrary power, package paths
• Support direct link to ICM
• Parser enforces differences

5
Pros and Cons

• Pros
• Focuses IBIS on value-add in multi-lingual
  world
• Makes connections intuitive again
• Removes obstacles to advanced development
• Cons
• Two-parsers-in-one required
• Dual-meaning of keywords depending on context
• e.g., Pin will have different rules for both
  modes
• Some retooling of passed BIRDs required