The system COMPAS and BCOMPAS are a software for finding a compressed test pattern sequence. The tools reduce the memory requirements for storing test patterns. The patterns are decompressed during the testing phase in the scan chain.
The algorithm of finding the compressed scan chain sequence reorders and overlaps the patterns previously generated with the help of an ATPG. Possible application of the compressed sequence generated by COMPAS can be found here.
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The system COMPAS is suited for multicore SOCs. The BCOMPAS system can be used for single core, as it has lower hardware overhead.
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| Possible ATPG tool is ATALANTA with parametr -Z (one test pattern for each fault). The COMPAS uses HOPE or FSIM fault simulation tool. DOWNLOAD |
| Circuit bench file example c880.bench and test patterns file example c880.test. |
The major versions of the COMPAS compressor are:
- Initial version, that uses direct pattern overlapping. Does not use bit prediction and hard-to-test fault detection.
- Bit prediction algorithm. (Improves compression and speed.)
- Hard to test fault detection and preference. (Further improves compression.)
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The major versions of the BCOMPAS compressor are:
- Initial version of broadcast compressor.
- Scan-chain optimized version.
- Broadcast compressor r.2013 version (efficiency improvement).
- Script controlled version r.2014. Controlled via command line or by user provided script.
- Version r.2015 (5.5alpha1). Fully scriptable via embedded Lua engine. Controlled via command line or by user provided script.
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