Elements of STIL

Standard • Test In. terface ____________________ Language So I was wrong. I was absolutely sure that by having an IEEE Standard defined, reviewed, and accepted, that I wouldn't need to write a book about it as well. The Standard would be the complete reference. And be aware - this book does not serve as a replacement to the IEEE Std. 1450 document. You should have a copy of the Standard as you go through this book. I realized that the Standard would not be the complete reference, about the time that the Working Group started to put notes into the draft proposa- notes to elaborate decisions in the Working Group, but that would be removed in the final draft. Then, once the Standard was accepted I became the central point of contact for people who just picked up the Standard, who didn't have the benefit of the Working Group discussions, who only had available that one final sentence in the Standard and who didn't benefit from the perspective of where those words came from. Sometimes those questions have resulted in clarifications to the Standard. Sometimes I would respond to those questions with more background and perspective as well. It is this additional background and perspective I hope you find in this book.

1 Foundations of STIL.- 1.1 Introduction.- 1.2 Organization of this Book.- 1.3 History.- 1.4 Foundation Efforts.- 1.5 Scope of STIL and Follow-On Efforts.- 1.5.1 Negotiating the Scope Limits.- 1.5.2 Format or Language?.- 1.5.3 Compression and the Binary Format Discussion.- 1.5.4 Evolving Standards.- 1.6 Parallel Standards.- 2 STIL Test.- 2.1 Test Stresses.- 2.1.1 ASIC Test.- 2.1.2 Microprocessor Test.- 2.2 Test Strategies.- 2.2.1 Fault Models.- 2.2.2 Functional and Structural Testing.- 2.2.3 Single Stuck-At Fault Model.- 2.2.4 Bridging Faults Model.- 2.2.5 IDDqTesting.- 2.2.6 Delay Tests.- 2.2.7 Transition Fault Model.- 2.2.8 Path Delay Fault Model.- 2.2.9 Test Metrics.- 2.2.10 Fault Diagnosis.- 2.3 Test Behaviors.- 2.3.1 Signals.- 2.3.2 Stimulus and Response.- 2.3.3 Periodicity.- 2.3.4 Output Response Constraints.- 2.4 Test Induced Faults.- 2.4.1 Packaging Effects.- 2.4.2 Simultaneous Switching Outputs.- 2.4.3 Guardbanding.- 2.5 Other Applications of STIL.- 3 Signals.- 3.1 Signals.- 3.1.1 User Names Characteristics.- 3.1.2 Really Long User Names and Concatenation.- 3.1.3 Types of Signals.- 3.2 Signal Arrays.- 3.3 SignalGroups.- 3.3.1 SignalGroup Block Names.- 3.3.2 SignalGroup Evaluation and Name Resolution.- 3.3.3 Applications of SignalGroups.- 3.4 STIL Statement Constructs and Block Structure.- 3.4.1 Single Statements Construct.- 3.4.2 Block Statements Construct.- 3.4.3 Named Blocks.- 3.4.4 Reserving the Leading Keyword.- 3.5 Signals and SignalGroups Syntax.- 3.6 Signal and SignalGroup Attributes.- 3.7 The Test Attributes.- 3.7.1 Application of the Test Attributes.- 3.7.2 Propagation of the Test Attributes.- 3.7.3 Two Usage Models for the Test Attributes.- 3.8 WGL Signals.- 4 Timing.- 4.1 The Timing Block.- 4.2 Event Statements.- 4.2.1 States and Levels.- 4.2.2 ForceUnknown, ‘N’.- 4.2.3 The Difference Between Compare and Expect States.- 4.2.4 The Relationship Between Drive and Compare States.- 4.3 Basic Time Expressions.- 4.4 Waveforms.- 4.4.1 Types of Waveforms.- 4.4.2 Waveform Styles.- 4.5 WaveformCharacters.- 4.6 Merging Common Waveforms.- 4.7 Event Ordering and Persistence.- 4.8 Maintaining Related Events.- 4.8.1 End-Strobe Relationships.- 4.8.2 Delayed Pulse or NRZ Waveforms.- 4.9 Special Events.- 4.9.1 Time-Zero Event.- 4.9.2 Tristate Events.- 4.10 The Rest of the Timing Block Syntax.- 4.10.1 Period Statement.- 4.10.2 Signal Reference Resolution in Timing.- 4.11 WGL Timing Constructs.- 5 Patterns.- 5.1 Fundamental Pattern Constructs.- 5.2 Statement Order Dependency.- 5.3 WaveformTable Reference Statement.- 5.4 Signal Assignment.- 5.4.1 Multiple Signal Assignment.- 5.4.2 Multiple Based Signal Assignment.- 5.4.3 Decimal Mapping.- 5.4.4 Default Attributes.- 5.4.5 WFC Expressions.- 5.4.6 Mixing Modifiers.- 5.5 Vectors.- 5.6 Conditions.- 5.7 Incremental Behavior.- 5.8 Loop Constructs.- 5.8.1 Loop Statement.- 5.8.2 MatchLoop.- 5.8.3 Other Loops.- 5.9 Labels.- 5.10 Stop and IDDQTestPoint.- 5.11 Breakpoint.- 5.12 WGL Pattern Constructs.- 6 Tying It All Together.- 6.1 Basic STIL Information Flow.- 6.2 The PatternBurst.- 6.2.1 Basic PatternBurst.- 6.2.2 Hierarchical PatternBursts.- 6.2.3 Environment/Context Statements in the PatternBurst.- 6.2.4 PatternBurst Organizations.- 6.3 The PatternExec.- 6.4 Additional STIL Constructs.- 6.4.1 STIL block.- 6.4.2 Header block.- 6.4.3 Annotations.- 6.4.4 Comments.- 6.5 STIL Block Order.- 6.6 WGL Constructs.- 7 Files and the Include Statement.- 7.1 Include Statement.- 7.1.1 Relative File Path Naming.- 7.1.2 Absolute File Path Naming.- 7.1.3 Using Logicals in the Path Name.- 7.2 The IfNeed Option.- 7.3 Additional File Constructs and Behaviors.- 8 Specifications.- 8.1 Device Operating Specifications.- 8.2 STIL Extensions to the Spec Variables.- 8.3 Spec and Category.- 8.4 Spec Variable Resolution.- 8.5 Based Expressions.- 8.6 Selector.- 8.7 Applying Spec Variables.- 8.8 More Spec Constructs.- 8.8.1 Explicit Spec Variable Type Referencing.- 8.8.2 The Spec Variable Meas Type.- 8.9 Relative Waveform Timing.- 8.10 Styles of Timing Representation.- 8.11 WGL Specification Constructs.- 9 Partitioning Timing.- 9.1 All-Waveforms-in-One-Table.- 9.2 One-Waveform-Per-Table.- 9.3 Happier Mediums.- 9.3.1 WaveformCharacter Conventions.- 9.3.2 Common Waveform Groups.- 9.4 Waveform Grouping/Merging.- 9.5 WGL Pattern Data and WaveformCharacters.- 10 Advanced Timing.- 10.1 Incremental Timing Definitions.- 10.1.1 Waveform Labels.- 10.1.2 Inherit Statements in the Timing Block.- 10.1.3 InheritWaveformTable timing_name.wft_name.- 10.1.4 InheritWaveform timing_name.wft_name.wave_label.- 10.1.5 InheritWaveform timing_name.wft_name.wave_label.wfc.- 10.1.6 Inherited Information Resolution.- 10.1.7 Inherited signal_reference Resolution.- 10.1.8 The Syntax Issue with Inherit Names and Concatenation.- 10.2 Inherit Strategies.- 10.2.1 InheritWaveformTable Examples.- 10.2.2 Inheriting Separated Time and State in Waveforms.- 10.3 SubWaveforms.- 10.4 Multiple Data Waveforms.- 11 Procedures and Macros.- 11.1 Structured Test Development.- 11.2 STIL Procedures.- 11.3 MacroDefs.- 11.4 Differences Between Procedures and Macros.- 11.5 Procedure and Macro Parameters.- 11.5.1 Single Parameter Application.- 11.5.2 Multiple Parameter Application.- 11.6 Calling Procedures and Macros.- 11.6.1 Parameter Passing By Name.- 11.6.2 Parameter Passing By Contents.- 11.6.3 Extra Parameters.- 11.6.4 Missing Parameters.- 11.7 Using Named Procedures/MacroDefs Blocks.- 11.8 WGL Procedures and Macros.- 12 STIL Scan.- 12.1 Scan Design.- 12.1.1 Scan Operation (Design).- 12.1.2 Scan Process (Test).- 12.1.3 Characteristics of a Scan Test.- 12.2 STIL Scan Constructs.- 12.2.1 The Shift Block.- 12.2.2 Scanln and ScanOut Attributes.- 12.2.3 ScanStructures Block.- 12.2.4 ScanStructures PatternBurst Statement.- 12.2.5 ScanChain Pattern Statement.- 12.3 Scan Data Alignment (“Scan Padding”).- 12.4 More Considerations on Scan Constructs.- 12.4.1 Pre-shift and Post-Shift Scan Data Consumption.- 12.4.2 The STIL Shift Calculation.- 12.4.3 The STIL Scan Pad State.- 12.5 Scan Groups.- 12.6 An Example: Transition Testing.- 12.7 WGL Scan.- 13 STIL Levels.- 13.1 STIL Statement with Extensions.- 13.2 Static and Dynamic Levels.- 13.3 Static Levels.- 13.3.1 DCLevels Statements.- 13.3.2 States and Levels.- 13.3.3 Applying DCLevels in the Test.- 13.4 Inter-cycle Dynamic Levels.- 13.4.1 Interaction of DCLevels and DCSets in the PatteraExec.- 13.5 Intra-cycle Dynamic Levels.- 13.6 DCSequence.- 13.7 Inherit Constructs.- 13.8 STIL Blocks and Data.- 14 More Pattern Constructs.- 14.1 Event-based Pattern Data.- 15 User Extensions.- 15.1 UserKeywords statement.- 15.2 Ambiguous Scenarios.- 15.3 UserFunctions.- 16 Additional Test Considerations.- 16.1 The Concept of Test Constraints.- 17 Name Mapping.- 17.1 Signal Names.- Terminology.- STIL Syntax Summary.