Pipeline of additional storage elements to shift input/output data of combinational scan compression circuit
US7823034B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 2007 |
| Grant date | Oct 26, 2010 |
| Priority date | — |
| Expiry date | Mar 24, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/318547
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electronic device includes a scan-based circuit that includes a combinational decompressor, a combinational compressor, scan chains, and logic which typically includes a number of storage elements. Cycle time normally needed to shift data into or out of a scan cell to/from an external interface of the electronic device is reduced by use of one or more additional storage element(s) located between the external interface and one of the combinational elements (decompressor/compressor). The one or more additional storage element(s) form a pipeline that shifts compressed data in stages, across small portions of an otherwise long path between the external interface and one of the combinational elements. Staged shifting causes the limit on cycle time to drop to the longest time required to traverse a stage of the pipeline. The reduced cycle time in turn enables a corresponding increase in shift frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.