Overview
IEC 62525:2007 - Standard Test Interface Language (STIL) for Digital Test Vector Data - specifies a vendor-neutral test description language for exchanging large volumes of digital test vector data between CAE (computer-aided engineering) environments and automated test equipment (ATE). STIL encodes pattern, format, and timing information sufficient to define how digital test vectors are applied to a device under test (DUT). The standard is optimized for high-volume structured tests (scan/ATPG), integral techniques (BIST), and functional test specifications for ICs and assemblies.
Key Topics
- Test vector exchange: Standardized representation to transfer bulk digital test vectors from CAE tools to ATE systems.
- Pattern and timing definitions: Describes pattern formats, waveform events, and timing expressions needed for accurate signal application on ATE.
- Support for structured tests: Accommodates scan tests, ATPG outputs, and advanced scan constructs used in IC test flows.
- Integral test support: Enables representation of built-in self-test (BIST) and other integral test techniques.
- Pattern organization and reuse: Includes constructs for pattern blocks, pattern execution, pattern bursts, macros, loops, and procedure calls to minimize file size and improve readability.
- Waveform and timing tables: WaveformTable and Timing blocks provide event-based timing and waveform character definitions for ATE application.
- Cyclized and non-cyclized data: Supports both cyclic vector data (repeated patterns) and event/non-cyclized sequences for flexible test definition.
- Scan structure representation: ScanStructures block and related statements for managing chain definitions and scan-specific pattern data.
- File modularity: Include, header, and annotation facilities to organize multi-file test descriptions.
Applications
- ATE vendors: Implement STIL parsers to load CAE-generated test data directly into test handlers and handlers’ sequencers.
- Test engineers & manufacturing: Use STIL to ensure consistent, repeatable application of digital tests across production ATE platforms.
- CAE & ATPG tool developers: Export test vectors in STIL to enable seamless handoff to diverse ATE ecosystems.
- IC design teams: Document and transfer functional test specifications, scan patterns, and BIST vectors for silicon validation and production test.
Benefits include reduced translation errors, improved interoperability between CAE and ATE, and efficient handling of large vector data volumes.
Related Standards
- IEEE Std 1450 (reference present in the IEC publication) - aligns STIL with existing IEEE test-data practices.
- IEEE Std 1149.1 (JTAG/scan) - referenced for scan-related test structures and compatibility considerations.
Keywords: IEC 62525, STIL, Standard Test Interface Language, digital test vector data, ATE, CAE, ATPG, scan, BIST, waveform, timing, pattern, DUT.