Serial scan chain architecture for a data processing system and method of operation
US5592493A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1994 |
| Grant date | Jan 7, 1997 |
| Priority date | — |
| Expiry date | Sep 13, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/318558
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A scan chain architecture which has a controller (10), and a multiplexer (24) is used to route test data through functional units (12, 14, 16, 18, 20, and 22). The controller (10) receives as input a serial data stream from an STDI terminal and demultiplexes this data stream to one of the functional units (six functional units are illustrated in FIG. 1). Each of the functional units is considered as one scan chain and therefore FIG. 1 has six scan chains (one for each functional unit). In addition, a seventh scan chain couples all output flip-flops in each of the functional units together between an output of the MUX (24) and the STDO terminal/pin. Therefore, a serial scan of a data stream can be done through one functional unit, the multiplexer (24) and into the output flip-flops of each function unit to make testing easier to set-up. In addition, various new scan chain cells and low power methods are used herein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.